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  • richardmitnick 9:23 am on April 24, 2017 Permalink | Reply
    Tags: , , , , Breaking Planet Chains and Cracking the Kepler Dichotomy, , Kepler Dichotomy, NASA Kepler, Planetary migration   

    From astrobites: “Breaking Planet Chains and Cracking the Kepler Dichotomy” 

    Astrobites bloc

    Astrobites

    Apr 24, 2017
    Michael Hammer

    Title: Breaking the Chains: Hot Super-Earth systems from migration and disruption of compact resonant chains
    Authors: Andre Izidoro, Masahiro Ogihara, Sean N. Raymond, Alessandro Morbidelli, Arnaud Pierens, Bertram Bitsch, Christophe Cossou, Franck Hersant
    First Author’s Institution: Laboratoire d’astrophysique de Bordeaux, University of Bordeaux
    1
    3

    Status: Submitted to MNRAS [open access]

    To migrate, or not to migrate? That is the question. Of course, since planets are not Shakespearean characters, they should not have a choice! When a planet forms in a disk, it creates two spiral waves: a weaker one ahead of the planet that drags it forward (sending the planet outwards), and a stronger one behind the planet that pulls it backwards (sending the planet inwards). Ultimately, every planet should migrate inwards and in most cases, end up much closer to its star than where it formed.

    When planets in the outer disk migrate inwards faster than planets closer in, they start to catch up to each other. As these planets get closer together, they eventually become gravitationally locked into resonance: pairs of orbits where the outer planet takes exactly twice as long (or another integer ratio such as 3-to-2, etc.) to complete an orbit around its star as the inner one. Once this happens, the planets migrate together, maintaining that 2-to-1 ratio. In systems with many rocky planets, the third one will follow suit and fall into a resonance with the second planet, as will the fourth with the third, and so on. Eventually, the system will have a long chain of up to 10 resonant rocky planets tightly packed in the inner part of the disk!

    Yet even though migration is supposed to be inevitable, only about 5% of the planetary systems discovered by the Kepler mission are actually in this setup (TRAPPIST-1 is the most famous).

    The TRAPPIST-1 star, an ultracool dwarf, is orbited by seven Earth-size planets (NASA).

    The other 95% are not, many of which because they only have one planet. Today’s paper, led by Andre Izidoro, attempts to explain these discrepancies by suggesting that all systems migrate into resonant chains, but not all of them stay in resonant chains!

    Two-Phase Setup

    Izidoro et al. study this problem by conducting two-phase N-body simulations of 120 hypothetical planetary systems with 20 to 30 rocky planets for 100 Myr. These planets start out with 0.1 to 4.5 Earth masses and are spread out evenly in the outer disk beyond 5 AU.

    In phase one (0 to 5 Myr), the planets may migrate due to the presence of a gaseous protoplanetary disk. Meanwhile, the disk also keeps the planets on flat, circular orbits by damping the planets’ eccentricities and inclinations.
    In phase two (5 to 100 Myr), the planets can no longer migrate since the disk has dissipated away. However, they are free to develop eccentric and inclined orbits since they are now controlled by interactions with each other instead of interactions with the disk.

    Compact, but not too compact

    Izidoro et al. find that all of their planetary systems migrate into compact resonant chains within 1.5 Myr, safely less than the disk’s lifetime of 5 Myr. Many of these systems (40%) then survive as resonant chains for the entire 100 Myr simulation.

    However, some systems (60%) become too compact (see Figure 1). In particular, the ones that are too compact with higher mass planets become unstable after the disk fades away! The resonant chains then collapse as some of the planets eject and the rest spread farther apart. As they spread out, the surviving planets’ orbits also become more eccentric and inclined.

    2
    Figure 1. Two example resonant chains after phase one. The first system (left) will survive phase two (without the disk). The second system (right) will become unstable because it has more planets too close together. Some of the surviving planets will develop inclined orbits, making them less likely to transit. Adapted from Figs. 2 and 3 of the paper.

    Single-Planet Imposters

    In order to compare their results with actual exoplanet systems discovered by the Kepler Mission, Izidoro et al. must determine what fraction of their planets can transit (and be “detected” by Kepler).

    Planet transit. NASA/Ames

    NASA/Kepler Telescope

    They find that in the stable resonant chains, Kepler can detect 3 or more planets in 66% of these systems. On the other side in the unstable systems, the inclined orbits from the instabilities make it so that Kepler can only detect 1 planet in 78% of these systems, even though over 90% of the unstable systems still have multiple planets.

    Explaining the Kepler Dichotomy

    One of the defining features of Kepler’s planets is the large number of systems with only one transiting planet. Naturally, we expected that Kepler would not be able to find all of the planets in each of its systems since planets at large separations from their star that do not line up with our line-of-sight will not transit. However even with this bias, the fact that there are so many more single-planet systems than two-planet systems (see Figure 2) suggests that Kepler systems belong to a dichotomy: roughly 50% of all systems have just one planet (including non-transiting ones) and 50% have many planets (5+ for small stars). Such a high fraction of single-planet systems is a huge surprise, given how many planets exist in our own solar system.

    However, the two populations of planetary systems in this study offer an explanation for the Kepler dichotomy that would imply these single planets are not so lonely. Izidoro et al. calculate that if no more than 25% of all planetary systems are compact resonant chains (with the rest being unstable systems), this distribution of systems can match the high fraction of systems with just one transiting planet in the Kepler dichotomy — even though nearly all of these systems would have multiple planets.

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    Figure 2. Comparison of Kepler’s planetary systems to this paper’s planetary systems. In the Kepler sample (green), the vast majority of systems have only one transiting planet. The unstable systems in this paper (blue) would have even more single-transit systems, while the stable resonant chains (red) have a lot fewer. A proper balance between these two (90% unstable, 10% stable — gray) matches the Kepler dichotomy pretty well. Fig. 15 of the paper.

    Why so unstable?

    Izidoro et al. expect that in reality, roughly 5% of all planetary systems are stable resonant chains (since this is the fraction found by Kepler), which is consistent with their upper limit of 25% they need to explain the dichotomy. Even though the authors find that 40% remain stable in their study, they suspect that simulations with a more realistic protoplanetary disk would lead to many more systems going unstable. Nonetheless, the authors caution that their model remains incomplete until they find a reason for ~95% of Kepler’s systems becoming unstable at some point in their history.

    It may also be the case that not all systems migrate into resonant chains to begin with, or even that planets do not migrate as easily as this study presumes. For now, we can still take solace in knowing that at least some of Kepler’s single-planet systems have non-transiting companions that they can orbit with for billions of years.

    See the full article here .

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    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.
    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 7:21 am on April 24, 2017 Permalink | Reply
    Tags: , , , , NASA Kepler, Natalie Batalha,   

    From Many Worlds: Women in STEM – “The Influential Natalie Batalha” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-04-24
    Marc Kaufman

    1
    Natalie Batalha, project scientist for the Kepler mission and a leader of NASA’s NExSS initiative on exoplanets, was just selected as one of Time Magazine’s 100 most influential people in the world. (NASA, TIME Magazine.)

    I’d like to make a slight detour and talk not about the science of exoplanets and astrobiology, but rather a particular exoplanet scientist who I’ve had the pleasure to work with.

    The scientist is Natalie Batalha, who has been lead scientist for NASA’s landmark Kepler Space Telescope mission since soon after it launched in 2009, has serves on numerous top NASA panels and boards, and who is one of the scientists who guides the direction of this Many Worlds column.

    Last week, Batalha was named by TIME Magazine as one of the 100 most influential people in the world. This is a subjective (non-scientific) calculation for sure, but it nonetheless seems credible to me and to doubtless many others.

    Batalha and the Kepler team have identified more than 2500 exoplanets in one small section of the distant sky, with several thousand more candidates awaiting confirmation. Their work has once and for all nailed the fact that there are billions and billions of exoplanets out there.

    “NASA is incredibly proud of Natalie,” said Paul Hertz, astrophysics division director at NASA headquarters, after the Time selection was announced.

    “Her leadership on the Kepler mission and the study of exoplanets is helping to shape the quest to discover habitable exoplanets and search for life beyond the solar system. It’s wonderful to see her recognized for the influence she has had on the world – and on the way we see ourselves in the universe.”

    And William Borucki, who had the initial idea for the Kepler mission and worked for decades to get it approved and then to manage it, had this to say about Batalha:

    “She has made major contributions to the Kepler Mission throughout its development and operation. Natalie’s collaborative leadership style, and expert knowledge of the population of exoplanets in the galaxy, will provide guidance for the development of successor missions that will tell us more about the habitability of the planets orbiting nearby stars.”

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    Batalha has led the science mission of the Kepler Space Telescope since it launched in 2009. (NASA)

    As a sign of the perceived importance of exoplanet research, two of the other TIME influential 100 are discoverers of specific new worlds. They are Guillem Anglada-Escudé (who led a team that detected a planet orbiting Proxima Centauri) and Michael Gillon (whose team identified the potentially habitable planets around the Trappist-1 system.)

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

    The TRAPPIST-1 star, an ultracool dwarf, is orbited by seven Earth-size planets, NASA announced on Wednesday. (NASA)

    ESO Belgian robotic Trappist National Telescope at Cerro La Silla, Chile interior

    But Batalha, and no doubt the other two scientists, stress that they are part of a team and that the work they do is inherently collaborative. It absolutely requires that many others also do difficult jobs well.

    For Batalha, working in that kind of environment is a natural fit with her personality and skills. Having watched her at work many times, I can attest to her ability to be a strong leader with extremely high standards, while also being a kind of force for calm and inclusiveness.

    We worked together quite a bit on the establishing and running of this column, which is part of the NASA Nexus for Exoplanet System Science (NExSS) initiative to encourage interdisciplinary thinking and collaboration in exoplanet science.

    It was NASA’s astrobiology senior scientist Mary Voytek who set up the initiative and saw fit to start this column, and it was Batalha (along with several others) who helped guide and focus it in its early days.

    I think back to her patience. I was visiting her at NASA’s Ames Research Center in Silicon Valley and talking shop — meaning stars and planets and atmospheres and the like. While I had done a lot of science reporting by that time, astronomy was not a strong point (yet.)

    So in conversation she made a reference to stars on the Hertzsprung-Russell diagram and I must have had a somewhat blank look to me. She asked if I was familiar with Hertzsprung-Russell and I had to confess that I was not.

    Not missing a beat, she then went into an explanation of what is a basic feature of astronomy, and did it without a hint of impatience. She just wanted me to know what the diagram was and what it meant, and pushed ahead with good cheer to bring me up to speed — as I’m sure she has done many other times with many people of different levels of exposure to the logic and complexities of her very complex work.

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    Hertzsprung–Russell diagram with 22,000 stars plotted from the Hipparcos Catalogue and 1,000 from the Gliese Catalogue of nearby stars. Stars tend to fall only into certain regions of the diagram. The most prominent is the diagonal, going from the upper-left (hot and bright) to the lower-right (cooler and less bright), called the main sequence. In the lower-left is where white dwarfs are found, and above the main sequence are the subgiants, giants and supergiants. The Sun is found on the main sequence at luminosity 1 (absolute magnitude 4.8) and B−V color index 0.66 (temperature 5780 K, spectral type G2V). Wikipedia

    (Incidently, the Hertzsprung-Russell diagram plots each star on a graph measuring the star’s brightness against its temperature or color.)

    I mention this because part of Batalha’s influence has to do with her ability to communicate with individuals and audiences from the lay to the most scientifically sophisticated. Not surprisingly, she is often invited to be a speaker and I recommend catching her at the podium if you can.

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    By chance — or was it chance? — the three exoplanet scientists selected for the Time 100 were at Yuri Milner’s Breakthrough Discuss session Thursday when the news came out. On the left is Anglada-Escude, Batalha in the middle and Gillon on the right.

    Batalha was born in Northern California with absolutely no intention of being a scientist. Her idea of a scientist, in fact, was a guy in a white lab coat pouring chemicals into a beaker.

    As a young woman, she was an undergrad at the University of California at Berkeley and planned on going into business. But she had always been very good and advanced in math, and so she toyed with other paths. Then, one day, astronaut Rhea Setton came to her sorority. Setton had been a member of the same sorority and came to deliver a sorority pin she had taken up with during on a flight on the Space Shuttle.

    “That visit changed my path,” Batalha told me. “When I had that opportunity to see a woman astronaut, to see that working for NASA was a possibility, I decided to switch my major — from business to physics.”

    After getting her BA in physics from UC Berkeley, she continued in the field and earned a PhD in astrophysics from UC Santa Cruz. Batalha started her career as a stellar spectroscopist studying young, sun-like stars. Her studies took her to Brazil, Chile and, in 1995, Italy, where she was present at the scientific conference when the world learned of the first planet orbiting another star like our sun — 51 Pegasi b.

    It had quite an impact. Four years later, after a discussion with Kepler principal investigator Borucki at Ames about challenges that star spots present in distinguishing signals from transiting planets, she was hired to join the Kepler team. She has been working on the Kepler mission ever since.

    Asked how she would like to use her now publicly acknowledged “influence,” she returned to her work on the search for habitable planets, and potentially life, beyond earth.

    “We’ve seen that there’s such a keen public interest and an enormous scientific interest in terms of habitable worlds, and we have to keep that going,” she said. “This is a very hard problem to solve, and we need all hands on deck.”

    She said the effort has to be interdisciplinary and international to succeed, and she pointed to the two other time 100 exoplanet hunters selected. One is from Belgium and the other is working in the United Kingdom, but comes from Spain.

    When the nominal Kepler mission formally winds down in September, she says she looks forward to more actively engaging with the exoplanet science Kepler has made possible.

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    The small planets identified by Kepler as of one year ago that are small and orbit in the region around their star where water can exist as a liquid. NASA Ames/N. Batalha and W. Stenzel

    Batalha’s role in the NASA NExSS initiative offers a window into what makes her a leader — she excels at making things happen.

    Voytek and Shawn Domogal-Goldman of Goddard founded and oversee the group. They then chose Batalha two other leaders (Anthony Del Genio of the Goddard Institute for Space Studies and Dawn Gelino of NASA Exoplanet Science Institute ) to be the hands-on leaders of the 18 groups of scientists from a wide variety of American universities.

    (Asked why she selected Batalha, Voytek replied, “TIME is recognizing what motivated us to select her as one of the leaders for….NExSS. Her scientific and leadership excellence.”)

    This is the official NExSS task: “Teams will help classify the diversity of worlds being discovered, understand the potential habitability of these worlds, and develop tools and technologies needed in the search for life beyond Earth. Scientists are developing ways to identify habitable environments on these worlds and search for biosignatures, or signs of life. Central to the work of NExSS is understanding how biology interacts with the atmosphere, surface, oceans, and interior of a planet, and how these interactions are affected by the host star.”

    She has encouraged and helped create the kinds of collaborations that these tasks have made essential, but also helped identify upcoming problems and opportunities for exoplanet research and has started working on ways to address them. For instance, it became clear within the NExSS group and larger community that many, if not most exoplanet researchers would not be able to effectively apply for time to use the James Webb Space Telescope (JWST) for several years after it launched in late 2018.

    NASA/ESA/CSA Webb Telescope annotated

    To be awarded time on the telescope, researchers have to write detailed descriptions of what they plan to do and how they will do it. But how the giant telescope will operate in space is not entirely know — especially as relates to exoplanets. So it will be impossible for most researchers to make proposals and win time until JWST is already in space for at least two of its five years of operation.

    Led by Batalha, exoplanet scientists are now hashing out a short list of JWST targets that the community as a whole can agree should be the top priorities scientifically and to allow researchers to learn better how JWST works. As a result, they would be able to propose their own targets for research much more quickly in those early years of JWST operations. It’s the kind of community consensus building that Batalha is known for.

    She also has an important roles in the NASA Astrophysics Advisory Committee and hopes to use the skills she developed working with Kepler on the upcoming Transiting Exoplanet Survey Satellite (TESS) mission.

    NASA/TESS

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    Batalha preparing for the Science Walk in San Francisco on Earth Day.

    A mother of four (including daughter Natasha, who is on her way to also becoming an accomplished astrophysicist), Batalha is active on Facebook sharing her activities, her often poetic thoughts, and her strong views about scientific and other issues of the day.

    She was an active participant, for instance, in the National March for Science in San Francisco, posting photos and impressions along the way. I think it’s fair to say her presence was noticed with appreciation by others.

    And that returns us to what she considers to be some of her greatest potential “influence” — being an accomplished, high ranking and high profile NASA female scientist.

    “I don’t have to stand up and say to young women ‘You can do this.’ You can just exist doing your work and you become a role model. Like Rhea Setton did with me.”

    And it is probably no coincidence that four other senior (and demanding) positions on the Kepler mission are filled by women — two of whom were students in classes taught some years ago by Natalie Batalha.

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 11:03 am on January 29, 2017 Permalink | Reply
    Tags: , , , Dwarf Planet 2007 OR10, , , NASA Kepler,   

    From JPL-Caltech: “2007 OR10: Largest Unnamed World in the Solar System” 

    NASA JPL Banner

    JPL-Caltech

    May 11, 2016 [Just found this]
    Michele Johnson
    NASA Ames Research Center, Moffett Field, Calif.
    650-604-6982
    michele.johnson@nasa.gov

    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    Elizabeth.landau@jpl.nasa.gov

    Written by Preston Dyches
    Jet Propulsion Laboratory

    1
    New K2 results peg 2007 OR10 as the largest unnamed body in our solar system and the third largest of the current roster of about half a dozen dwarf planets. The dwarf planet Haumea has an oblong shape that is wider on its long axis than 2007 OR10, but its overall volume is smaller. Credits: Konkoly Observatory/András Pál, Hungarian Astronomical Association/Iván Éder, NASA/JHUAPL/SwRI

    Dwarf planets tend to be a mysterious bunch. With the exception of Ceres, which resides in the main asteroid belt between Mars and Jupiter, all members of this class of minor planets in our solar system lurk in the depths beyond Neptune. They are far from Earth – small and cold – which makes them difficult to observe, even with large telescopes. So it’s little wonder astronomers only discovered most of them in the past decade or so.

    Pluto is a prime example of this elusiveness. Before NASA’s New Horizons spacecraft visited it in 2015, the largest of the dwarf planets had appeared as little more than a fuzzy blob, even to the keen-eyed Hubble Space Telescope.

    NASA/New Horizons spacecraft
    NASA/New Horizons spacecraft

    NASA/ESA Hubble Telescope
    NASA/ESA Hubble Telescope

    Given the inherent challenges in trying to observe these far-flung worlds, astronomers often need to combine data from a variety of sources in order to tease out basic details about their properties.

    Recently, a group of astronomers did just that by combining data from two space observatories to reveal something surprising: a dwarf planet named 2007 OR10 is significantly larger than previously thought.


    Access mp4 video here .
    NASA’s Kepler spacecraft observed dwarf planet 2007 OR10 for 19 days in late 2014. The object’s apparent movement (indicated by the arrow) against the stars is caused by Kepler’s changing position as it orbits the sun. The diffuse light at right is from Mars, which was near the field of view. Credits: Konkoly Observatory/László Molnár and András Pál

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    The results peg 2007 OR10 as the largest unnamed world in our solar system and the third largest of the current roster of about half a dozen dwarf planets. The study also found that the object is quite dark and rotating more slowly than almost any other body orbiting our sun, taking close to 45 hours to complete its daily spin.

    For their research, the scientists used NASA’s repurposed planet-hunting Kepler space telescope — its mission now known as K2 — along with the archival data from the infrared Herschel Space Observatory. Herschel was a mission of the European Space Agency with NASA participation. The research paper reporting these results is published in The Astronomical Journal.

    “K2 has made yet another important contribution in revising the size estimate of 2007 OR10. But what’s really powerful is how combining K2 and Herschel data yields such a wealth of information about the object’s physical properties,” said Geert Barentsen, Kepler/K2 research scientist at NASA’s Ames Research Center in Moffett Field, California.

    ESA/Herschel spacecraft
    ESA/Herschel spacecraft

    The revised measurement of the planet’s diameter, 955 miles (1,535 kilometers), is about 60 miles (100 kilometers) greater than the next largest dwarf planet, Makemake, or about one-third smaller than Pluto. Another dwarf planet, named Haumea, has an oblong shape that is wider on its long axis than 2007 OR10, but its overall volume is smaller.

    Like its predecessor mission, K2 searches for the change in brightness of distant objects. The tiny, telltale dip in the brightness of a star can be the signature of a planet passing, or transiting, in front. But, closer to home, K2 also looks out into our solar system to observe small bodies such as comets, asteroids, moons and dwarf planets. Because of its exquisite sensitivity to small changes in brightness, Kepler is an excellent instrument for observing the brightness of distant solar system objects and how that changes as they rotate.

    Figuring out the size of small, faint objects far from Earth is tricky business. Since they appear as mere points of light, it can be a challenge to determine whether the light they emit represents a smaller, brighter object, or a larger, darker one. This is what makes it so difficult to observe 2007 OR10 — although its elliptical orbit brings it nearly as close to the sun as Neptune, it is currently twice as far from the sun as Pluto.

    Enter the dynamic duo of Kepler and Herschel.

    Previous estimates based on Herschel data alone suggested a diameter of roughly 795 miles (1,280 kilometers) for 2007 OR10. However, without a handle on the object’s rotation period, those studies were limited in their ability to estimate its overall brightness, and hence its size. The discovery of the very slow rotation by K2 was essential for the team to construct more detailed models that revealed the peculiarities of this dwarf planet. The rotation measurements even included hints of variations in brightness across its surface.

    Together, the two space telescopes allowed the team to measure the fraction of sunlight reflected by 2007 OR10 (using Kepler) and the fraction absorbed and later radiated back as heat (using Herschel). Putting these two data sets together provided an unambiguous estimation of the dwarf planet’s size and how reflective it is.

    According to the new measurements, the diameter of 2007 OR10 is some 155 miles (250 kilometers) larger than previously thought. The larger size also implies higher gravity and a very dark surface — the latter because the same amount of light is being reflected by a larger body. This dark nature is different from most dwarf planets, which are much brighter. Previous ground-based observations found 2007 OR10 has a characteristic red color, and other researchers have suggested this might be due to methane ices on its surface.

    “Our revised larger size for 2007 OR10 makes it increasingly likely the planet is covered in volatile ices of methane, carbon monoxide and nitrogen, which would be easily lost to space by a smaller object,” said András Pál at Konkoly Observatory in Budapest, Hungary, who led the research. “It’s thrilling to tease out details like this about a distant, new world — especially since it has such an exceptionally dark and reddish surface for its size.”

    As for when 2007 OR10 will finally get a name, that honor belongs to the object’s discoverers. Astronomers Meg Schwamb, Mike Brown and David Rabinowitz spotted it in 2007 as part of a survey to search for distant solar system bodies using the Samuel Oschin Telescope at Palomar Observatory near San Diego.

    Caltech Palomar  Samuel Oschin 48 inch Telescope
    Caltech Palomar  Samuel Oschin 48 inch Telescope Interior with Edwin Hubble
    Caltech Palomar Samuel Oschin 48 inch Telescope

    “The names of Pluto-sized bodies each tell a story about the characteristics of their respective objects. In the past, we haven’t known enough about 2007 OR10 to give it a name that would do it justice,” said Schwamb. “I think we’re coming to a point where we can give 2007 OR10 its rightful name.”

    Ames manages the Kepler and K2 missions for NASA’s Science Mission Directorate. NASA’s Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

    For more information about the Kepler and K2 missions, visit:

    http://www.nasa.gov/kepler

    More information about Herschel is online at:

    http://www.nasa.gov/herschel

    See the full article here .

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    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 1:08 pm on December 22, 2016 Permalink | Reply
    Tags: , , LAMOST telescope, NASA Kepler,   

    From Kavli: “Revealing the Orbital Shape Distributions of Exoplanets with China’s LAMOST Telescope” 

    KavliFoundation

    The Kavli Foundation

    12/22/2016

    Using data from China’s LAMOST telescope, a team of astronomers have derived how the orbital shapes distribute for extrasolar planets. The work is recently published in the journal Proceedings of the National Academy of Sciences of the United States of America” (PNAS). The lead authors are Prof. Jiwei Xie from Nanjing University and Prof. Subo Dong, a faculty member of the Kavli Institute of Astronomy & Astrophysics (KIAA) at Peking University.

    LAMOST telescope located in Xinglong Station, Hebei Province, China
    The Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST) telescope in Hebei, China. It is the most efficient spectroscopy machine in the world.

    Until two decades ago, the only planetary system known to mankind was our own solar system. Most planets in the solar system revolve around the Sun on nearly circular orbits, and their orbits are almost on the same plane within about 3 degrees on average (i.e., the averaged inclination angle is about 3 degrees). Astronomers use the parameter called eccentricity to describe the shape of a planetary orbit. Eccentricity takes the value between 0 and 1, and the larger the eccentricity, the more an orbit deviates from circular. The averaged eccentricity of solar system planets is merely 0.06. Hundreds of years ago, motivated by circular and coplanar planetary orbits, Kant and Laplace hypothesized that planets should form in disks, and this theory has developed into the “standard model” on how planets form.

    In 1995, astronomers discovered the first exoplanet around a Sun-like star 51 Pegasi with a technique called Radial Velocity, and this discovery started an exciting era of exoplanet exploration. At the beginning of the 21st Century, people had discovered hundreds of exoplanets with the Radial Velocity technique, and most of them are giant planets comparable in mass with the Jupiter. These Jovian planets are relatively rare, found around approximately one tenth of stars studied by the Radial Velocity technique. The shapes of their orbits were a big surprise: a large fraction of them are on highly eccentric orbits, and all the giant planets found by Radial Velocity have a mean eccentricity of about 0.3. This finding challenges the “standard model” of planet formation and raises a long-standing puzzle for astronomers – are the nearly circular and coplanar planetary orbits in the solar system common or exceptional?

    The Kepler satellite launched by NASA in 2009 has discovered thousands of exoplanets by monitoring tiny dimming in the brightness of stars when their planets happen to cross in the front (called “transit”).

    Planet transit. NASA/Ames
    Planet transit. NASA/Ames

    Many of the planets discovered by Kepler have sizes comparable to that of the Earth. Kepler’s revolutionary discoveries show that Earth-size planets are prevalent in our galaxy. However, data from the Kepler satellite alone cannot be used to measure the shape of a transiting exoplanet’s orbit. To do so, one way is to use the size of the planet host star as a “ruler” to measure against the length of the planet transit, while implementing this method needs precise information on the host star parameters such as size and mass. This method has previously been applied to the host stars characterized with the asteroseismology technique but the sample is limited to a relatively small number of stars with high-frequency, exquisite brightness information required by asteroseismology.

    With its innovative design, the LAMOST telescope in China can observe spectra of thousands of celestial objects simultaneously within its large field of view, and it is currently the most efficient spectroscopy machine in the world (Figure 1). In recent years, LAMOST has obtained tens of thousands of stellar spectra in the sky region where the Kepler satellite monitors planet transits, and they include many hundreds of stars hosting transiting exoplanets. By comparing with other methods such as asteroseismology, the research team finds that, high-accuracy characterization of stellar parameters can be reliably obtained from LAMOST spectra, and they can subsequently be used to measure the the orbital shape distributions of Kepler exoplanets.

    They analyze a large sample of about 700 exoplanets whose host stars have LAMOST spectra, and with the LAMOST stellar parameters and Kepler transit data, they measure the eccentricity and inclination angle distributions. They find that about 80% of the analyzed planet orbits are nearly circular (averaged eccentricity less than 0.1) like those in the solar system, and only about 20% of the planets are on relatively eccentric orbits that significantly deviate from circular (average eccentricity large than 0.3). They also find that the average eccentricity and inclination angle for the Kepler systems with multiple planets fit into the pattern of the solar system objects (Figure 2).

    Therefore, circular orbits are not exceptional for planetary systems, and the orbital shapes of most planets inside and outside the solar system appear to distribute in a similar fashion. This implies that the formation and evolution processes leading to the distributions of the orbital shapes of the solar system may be common in the Galaxy.

    See the full article here .

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    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
    • vegetarian dash diet meal pla 1:39 pm on December 22, 2016 Permalink | Reply

      You should take part in a contest for one of the highest quality blogs online.
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      • richardmitnick 2:27 pm on December 22, 2016 Permalink | Reply

        Thanks, I am just glad my work is appreciated. I do it for the love of bringing this material which the press ignores to the public. I have about 800 readers in North America , Europe, East Asia, Africa, and the Middle East. No contests.

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  • richardmitnick 2:18 pm on December 15, 2016 Permalink | Reply
    Tags: 1.3 meter OGLE Warsaw Telescope at the Las Campanas Observatory in Chile", , Lake Tekapo, , NASA Kepler, New Zealand, University of Canterbury Mt John Observatory   

    From Goddard: “Microlensing Study Suggests Most Common Outer Planets Likely Neptune-mass” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Dec. 15, 2016
    Francis Reddy
    francis.j.reddy@nasa.gov
    NASA’s Goddard Space Flight Center in Greenbelt, Maryland

    A new statistical study of planets found by a technique called gravitational microlensing suggests that Neptune-mass worlds are likely the most common type of planet to form in the icy outer realms of planetary systems. The study provides the first indication of the types of planets waiting to be found far from a host star, where scientists suspect planets form most efficiently.


    Neptune-mass worlds are likely the most common type in the outer realms of planetary systems
    Credits: NASA’s Goddard Space Flight Center

    1
    University of Canterbury Mt John Observatory, Lake Tekapo, New Zealand

    “We’ve found the apparent sweet spot in the sizes of cold planets. Contrary to some theoretical predictions, we infer from current detections that the most numerous have masses similar to Neptune, and there doesn’t seem to be the expected increase in number at lower masses,” said lead scientist Daisuke Suzuki, a post-doctoral researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland Baltimore County. “We conclude that Neptune-mass planets in these outer orbits are about 10 times more common than Jupiter-mass planets in Jupiter-like orbits.”

    Gravitational microlensing takes advantage of the light-bending effects of massive objects predicted by Einstein’s general theory of relativity.

    Gravitational microlensing
    Gravitational microlensing, S. Liebes, Physical Review B, 133 (1964): 835

    It occurs when a foreground star, the lens, randomly aligns with a distant background star, the source, as seen from Earth. As the lensing star drifts along in its orbit around the galaxy, the alignment shifts over days to weeks, changing the apparent brightness of the source. The precise pattern of these changes provides astronomers with clues about the nature of the lensing star, including any planets it may host.

    2
    This graph plots 4,769 exoplanets and planet candidates according to their masses and relative distances from the snow line, the point where water and other materials freeze solid (vertical cyan line). Gravitational microlensing is particularly sensitive to planets in this region. Planets are shaded according to the discovery technique listed at right. Masses for unconfirmed planetary candidates from NASA’s Kepler mission are calculated based on their sizes. For comparison, the graph also includes the planets of our solar system.
    Credits: NASA’s Goddard Space Flight Center

    “We mainly determine the mass ratio of the planet to the host star and their separation,” said team member David Bennett, an astrophysicist at Goddard. “For about 40 percent of microlensing planets, we can determine the mass of the host star and therefore the mass of the planet.”

    More than 50 exoplanets have been discovered using microlensing compared to thousands detected by other techniques, such as detecting the motion or dimming of a host star caused by the presence of planets. Because the necessary alignments between stars are rare and occur randomly, astronomers must monitor millions of stars for the tell-tale brightness changes that signal a microlensing event.

    However, microlensing holds great potential. It can detect planets hundreds of times more distant than most other methods, allowing astronomers to investigate a broad swath of our Milky Way galaxy. The technique can locate exoplanets at smaller masses and greater distances from their host stars, and it’s sensitive enough to find planets floating through the galaxy on their own, unbound to stars.

    NASA’s Kepler and K2 missions have been extraordinarily successful in finding planets that dim their host stars, with more than 2,500 confirmed discoveries to date.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    This technique is sensitive to close-in planets but not more distant ones. Microlensing surveys are complementary, best probing the outer parts of planetary systems with less sensitivity to planets closer to their stars.

    “Combining microlensing with other techniques provides us with a clearer overall picture of the planetary content of our galaxy,” said team member Takahiro Sumi at Osaka University in Japan.

    From 2007 to 2012, the Microlensing Observations in Astrophysics (MOA) group, a collaboration between researchers in Japan and New Zealand, issued 3,300 alerts informing the astronomical community about ongoing microlensing events. Suzuki’s team identified 1,474 well-observed microlensing events, with 22 displaying clear planetary signals. This includes four planets that were never previously reported.

    To study these events in greater detail, the team included data from the other major microlensing project operating over the same period, the Optical Gravitational Lensing Experiment (OGLE), as well as additional observations from other projects designed to follow up on MOA and OGLE alerts.

    1.3 meter OGLE Warsaw Telescope at the Las Campanas Observatory in Chile1.3 meter OGLE Warsaw telescope interior
    1.3 meter OGLE Warsaw Telescope at the Las Campanas Observatory in Chile”

    From this information, the researchers determined the frequency of planets compared to the mass ratio of the planet and star as well as the distances between them. For a typical planet-hosting star with about 60 percent the sun’s mass, the typical microlensing planet is a world between 10 and 40 times Earth’s mass. For comparison, Neptune in our own solar system has the equivalent mass of 17 Earths.

    The results imply that cold Neptune-mass worlds are likely to be the most common types of planets beyond the so-called snow line, the point where water remained frozen during planetary formation. In the solar system, the snow line is thought to have been located at about 2.7 times Earth’s mean distance from the sun, placing it in the middle of the main asteroid belt today.

    3
    Neptune-mass exoplanets like the one shown in this artist’s rendering may be the most common in the icy regions of planetary systems. Beyond a certain distance from a young star, water and other substances remain frozen, leading to an abundant population of icy objects that can collide and form the cores of new planets. In the foreground, an icy body left over from this period drifts past the planet.
    Credits: NASA/Goddard/Francis Reddy

    A paper detailing the findings was published in The Astrophysical Journal on Dec. 13.

    “Beyond the snow line, materials that were gaseous closer to the star condense into solid bodies, increasing the amount of material available to start the planet-building process,” said Suzuki. “This is where we think planetary formation was most efficient, and it’s also the region where microlensing is most sensitive.”

    NASA’s Wide Field Infrared Survey Telescope (WFIRST), slated to launch in the mid-2020s, will conduct an extensive microlensing survey.

    NASA/WFIRST
    NASA/WFIRST

    Astronomers expect it will deliver mass and distance determinations of thousands of planets, completing the work begun by Kepler and providing the first galactic census of planetary properties.

    NASA’s Ames Research Center manages the Kepler and K2 missions for NASA’s Science Mission Directorate. The Jet Propulsion Laboratory (JPL) in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

    WFIRST is managed at Goddard, with participation by JPL, the Space Telescope Science Institute in Baltimore, the Infrared Processing and Analysis Center, also in Pasadena, and a science team comprising members from U.S. research institutions across the country.

    For more information on how NASA’s Kepler is working with ground-based efforts, including the MOA and OGLE groups, to search for planets using microlensing, please visit:

    https://www.nasa.gov/feature/ames/kepler/searching-for-far-out-and-wandering-worlds/

    See the full article here.

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard campus
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 6:56 pm on June 13, 2016 Permalink | Reply
    Tags: , , , NASA Kepler, New Planet Is Largest Discovered That Orbits Two Suns   

    From Goddard: “New Planet Is Largest Discovered That Orbits Two Suns” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    June 13, 2016
    Ashley Morrow

    1
    Artist’s impression of the simultaneous stellar eclipse and planetary transit events on Kepler-1647.Credits: Lynette Cook

    If you cast your eyes toward the constellation Cygnus, you’ll be looking in the direction of the largest planet yet discovered around a double-star system. It’s too faint to see with the naked eye, but a team led by astronomers from NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and San Diego State University (SDSU) in California, used NASA’s Kepler Space Telescope to identify the new planet, Kepler-1647b.

    The discovery was announced today in San Diego at a meeting of the American Astronomical Society. The research has been accepted for publication in the Astrophysical Journal with Veselin Kostov, a NASA Goddard postdoctoral fellow, as lead author.

    Kepler-1647 is 3,700 light-years away and approximately 4.4 billion years old, roughly the same age as Earth. The stars are similar to the sun, with one slightly larger than our home star and the other slightly smaller. The planet has a mass and radius nearly identical to that of Jupiter, making it the largest transiting circumbinary planet ever found.

    Planets that orbit two stars are known as circumbinary planets, or sometimes “Tatooine” planets, after Luke Skywalker’s home world in “Star Wars.” Using Kepler data, astronomers search for slight dips in brightness that hint a planet might be passing or transiting in front of a star, blocking a tiny amount of the star’s light.

    “But finding circumbinary planets is much harder than finding planets around single stars,” said SDSU astronomer William Welsh, one of the paper’s coauthors. “The transits are not regularly spaced in time and they can vary in duration and even depth.”

    2
    Comparison of the relative sizes of several Kepler circumbinary planets. Kepler-1647 b is substantially larger than any of the previously known circumbinary planets. Credits: Lynette Cook

    3
    A bird’s eye view comparison of the orbits of the Kepler circumbinary planets. Kepler-1647 b’s orbit, shown in red, is much larger than the other planets (shown in gray). For comparison, the Earth’s orbit is shown in blue. Credits: B. Quarles

    “It’s a bit curious that this biggest planet took so long to confirm, since it is easier to find big planets than small ones,” said SDSU astronomer Jerome Orosz, a coauthor on the study. “But it is because its orbital period is so long.”

    The planet takes 1,107 days – just over three years – to orbit its host stars, the longest period of any confirmed transiting exoplanet found so far. The planet is also much further away from its stars than any other circumbinary planet, breaking with the tendency for circumbinary planets to have close-in orbits. Interestingly, its orbit puts the planet with in the so-called habitable zone–the range of distances from a star where liquid water might pool on the surface of an orbiting planet

    Like Jupiter, however, Kepler-1647b is a gas giant, making the planet unlikely to host life. Yet if the planet has large moons, they could potentially be suitable for life.

    “Habitability aside, Kepler-1647b is important because it is the tip of the iceberg of a theoretically predicted population of large, long-period circumbinary planets,” said Welsh.

    Once a candidate planet is found, researchers employ advanced computer programs to determine if it really is a planet. It can be a grueling process.

    Laurance Doyle, a coauthor on the paper and astronomer at the SETI Institute, noticed a transit back in 2011. But more data and several years of analysis were needed to confirm the transit was indeed caused by a circumbinary planet. A network of amateur astronomers in the Kilodegree Extremely Little Telescope “Follow-Up Network” provided additional observations that helped the researchers estimate the planet’s mass.

    For more information about the Kepler mission, please see:

    http://www.nasa.gov/kepler

    A preprint of the paper can be found at:

    http://arxiv.org/pdf/1512.00189v2

    High-resolution artwork can be obtained at:

    http://go.sdsu.edu/kepler/

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard Campus
    NASA/Goddard Campus
    NASA

     
  • richardmitnick 2:09 pm on June 11, 2016 Permalink | Reply
    Tags: , , Kepler-22b, NASA Kepler   

    From CosmosUp: “Kepler 22b: Meet an Extraordinary Planet” 

    CosmosUp bloc

    CosmosUp

    11, Jun 2016
    No writer credit found

    In constellation Cygnus the swan, about 600 light years away from us, sits an amazing planet that could have continents, oceans and creatures already living on its surface, a place that is just right in meeting all the requirements for life, Kepler 22b.

    We knew about Kepler 22b since 7 Dec. 2011, when NASA’s scientists confirmed and validated the planet after 22 month period of observations, Kepler 22b was the first planet in the “habitable zone” of it’s star to be discovered.

    Remember, we refer to the habitable zone as a region around a star where a rocky planet could have a surface temperature between the freezing point and boiling point of water, the region where liquid water could exist on a planet’s surface.

    Kepler 22b orbits around a star like our sun, a bit smaller and colder, every 290 days; its 15% closer than the Earth is from the Sun. Scientists’ models suggest the planet has comfortable average surface temperature of 22°C (72°F) which sounds remarkably clement.

    As such temperature, the planet is warm enough that it could have liquid water on its surface or even large ocean, as some researchers suggest.

    “It’s not beyond the realm of possibility that life could exist in such an ocean,”

    said Natalie Batalha in an interview.

    1

    How did we find Kepler 22b

    Since March 2009, astronomers use Kepler Space Telescope to hunt for exoplanets, planets beyond our solar system orbiting stars other than the sun. Kepler Telescope is a NASA space probe specially designed to survey our region of the Milky Way looking for alien worlds that resembles our planet, located in or near the habitable zone of their host stars.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    Kepler is our best instrument that allow us to glimpse into far distant realms, hunting for potential Earth-like planets in our galaxy, the Milky Way. The telescope is staring intently at 155,000 stars in the region of the constellations of Lyra and Cygnus, looking for tiny drops in brightness over time.

    If a planet passes (“transit”) in front of its parent star, we see a small dip in star’ brightness as the planet dimming it’s light by a minuscule amount — this is called by astronomers the transit method.

    Planet transit. NASA
    Planet transit. NASA

    In order to confirm if a planet is actually true, Kepler requires at least 3 transits to verify a signal as a planet.

    Up to June 2016, Kepler has confirmed more than 2,350 exoplanets and even twice waiting candidates; among them are 207 Earth-sized planets but just 21 are small, located in the habitable zone.

    “Fortune smiled upon us with the detection of this planet,

    said then William Borucki who led the team that discovered Kepler-22b.

    The first transit was captured just three days after we declared the spacecraft operationally ready. We witnessed the defining third transit over the 2010 holiday season.”

    2

    Based on the 3 transits observed in the 22-month period between 12 May 2009 and 14 March 2011, Kepler 22b has been validated. By December 2011, NASA was able to confirm Kepler-22b’s existence and announced it as part of a larger press conference.

    “We’re getting closer and closer to discovering the so-called ‘Goldilocks planet,”

    said Pete Worden.

    Can the Kepler 22b support life?

    We actually don’t know, the planet is too far away to scrutiny this world but it’s reasonable to suggest that having liquid water on the surface of the planet would make a good start.

    As the planet is located withing the habitable zone & with an average temperature of 22°C the planet is pleasantly warm and thus liquid water could be there so it can be included in a list of “optimistic” habitable worlds.

    However, some researchers put in question the habitability of this planet, indicating that Kepler-22b, is far from a twin to Earth. Transit observations allowed scientists to determine the planet’s size and it turns out, Kepler 22b is around 2.4 times the radius of Earth — That’s roughly half way between the size of Earth and the size of gas giants Uranus and Neptune.

    So what is that mean? Kepler 22b is most likely a super-Earth and probably has a thick atmosphere which, in turn, probably means the true surface temperature will be higher than the optimistic 22°C.

    “Indeed, if the atmosphere of the planet is sufficiently dense, and rich in greenhouse gasses, it might well be more like Venus than the Earth, with a surface far too warm to house liquid water.”

    Explained Jonti Horner, Post Doctoral Research Fellow, UNSW Australia.

    But again, we don’t know… More data on Kepler-22b is required to determine if the planet is a rocky planet with large ocean or a planet more like Venus or Neptune.

    But if Kepler 22b is more like Earth then how far is it? Well, Kepler 22b is 600 light years that’s 3,527,175,223,910,165 or three and a half quadrillion miles away. Even if we could make somehow a ship that could travel at speed of light it would take 600 years to reach Kepler 22 star system.

    But what about our current technology? The fastest man-made object is Voyager 1 with some 17.05 kilometers per second; with such spacecraft it would take well over 8,400,000 years to reach it, clearly we need something like a worm hole to shorten the distance.

    See the full article here .

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  • richardmitnick 2:07 pm on May 17, 2016 Permalink | Reply
    Tags: , , Kepler-223 System: Clues to Planetary Migration, NASA Kepler   

    From Kepler: “Kepler-223 System: Clues to Planetary Migration” 

    NASA Kepler Logo

    NASA Kepler Telescope
    NASA/Kepler

    May 17, 2016
    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    elizabeth.landau@jpl.nasa.gov

    Michele Johnson
    NASA Ames Research Center, Moffett Field, Calif.
    650-604-6982
    michele.johnson@nasa.gov

    Written by Steve Koppes
    University of Chicago
    773-702-8366
    skoppes@uchicago.edu

    1
    The Kepler-223 planetary system. Image credit: W. Rebel.

    The four planets of the Kepler-223 star system appeared to have little in common with the planets of our own solar system today. But a new study using data from NASA’s Kepler space telescope suggests a possible commonality in the distant past. The Kepler-223 planets orbit their star in the same configuration that Jupiter, Saturn, Uranus and Neptune may have had in the early history of our solar system, before migrating to their current locations.

    “Exactly how and where planets form is an outstanding question in planetary science,” said the study’s lead author, Sean Mills, a graduate student in astronomy and astrophysics at the University of Chicago in Illinois. “Our work essentially tests a model for planet formation for a type of planet we don’t have in our solar system.”

    2
    Sean Mills (left) and Daniel Fabrycky (right), researchers at the University of Chicago, describe the complex orbital structure of the Kepler-223 system in a new study. Credits: Nancy Wong/University of Chicago

    Mills and his collaborators used data from Kepler — its mission is now known as K2 — to analyze how the four planets block their stars’ light and change each other’s orbits. This information also gave researchers the planets’ sizes and masses. The team performed numerical simulations of planetary migration that generate this system’s current architecture, similar to the migration suspected for the solar system’s gas giants. These calculations are described* in the May 11 Advance Online edition of Nature.


    Access mp4 video here . No video credit.
    These animations show approximately 200,000 years of orbital evolution in the Kepler-223 planetary system. The planets’ interactions with the disk of gas and dust in which they formed caused their orbits to shrink toward their star over time at differing rates.

    The orbital configuration of our own solar system seems to have evolved since its birth 4.6 billion years ago. The four known planets of the much older Kepler-223 system, however, have maintained a single orbital configuration for far longer.

    Astronomers call the planets of Kepler-223 “sub-Neptunes.” They likely consist of a solid core and an envelope of gas, and they orbit their star in periods ranging from only seven to 19 days. They are the most common type of planets known in the galaxy, even though there is nothing quite like them around our sun.

    Kepler-223’s planets also are in resonance, meaning their gravitational influence on each other creates a periodic relationship between their orbits. Planets are in resonance when, for example, every time one of them orbits its sun once, the next one goes around twice. Three of Jupiter’s largest moons, where the phenomenon was discovered, display resonances. Kepler-223 is the first time that four planets in an extrasolar system have been confirmed to be in resonance.

    “This is the most extreme example of this phenomenon,” said study co-author Daniel Fabrycky, an assistant professor of astronomy and astrophysics at the University of Chicago.

    Formation scenarios

    The Kepler-223 system provides alternative scenarios for how planets form and migrate in a planetary system that is different from our own, said study co-author Howard Isaacson, a research astronomer at the University of California, Berkeley, and member of the California Planet Search Team.

    “Data from Kepler and the Keck Telescope were absolutely critical in this regard,” Isaacson said.

    Keck Observatory, Mauna Kea, Hawaii, USA
    Keck Observatory Interior
    Keck Observatory, Mauna Kea, Hawaii, USA

    Thanks to observations of Kepler-223 and other exoplanetary systems, “We now know of systems that are unlike our sun’s solar system, with hot Jupiters, planets closer than Mercury or in between the size of Earth and Neptune, none of which we see in our solar system. Other types of planets are very common.”

    Some stages of planet formation can involve violent processes. But during other stages, planets can evolve from gaseous disks in a smooth, gentle way, which is probably what the sub-Neptune planets of Kepler-223 did, Mills said.

    “We think that two planets migrate through this disk, get stuck and then keep migrating together; find a third planet, get stuck, migrate together; find a fourth planet and get stuck,” Mills explained.

    That process differs completely from the one that scientists believe led to the formation of Mercury, Venus, Earth and Mars, which likely formed in their current orbital locations.

    Earth formed from Mars-sized or moon-sized bodies smacking together, Mills said, in a violent and chaotic process. When planets form this way, their final orbital periods are not near a resonance.

    Substantial movement

    But scientists suspect that the solar system’s larger, more distant planets of today — Jupiter, Saturn, Uranus and Neptune — moved around substantially during their formation. They may have been knocked out of resonances that once resembled those of Kepler-223, possibly after interacting with numerous asteroids and small planets (planetesimals).

    “These resonances are extremely fragile,” Fabrycky said. “If bodies were flying around and hitting each other, then they would have dislodged the planets from the resonance.” But Kepler-223’s planets somehow managed to dodge this scattering of cosmic bodies.

    *Science article:
    A resonant chain of four transiting, sub-Neptune planets

    See the full article here .

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    The Kepler Mission, NASA Discovery mission #10, is specifically designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone→ and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets.
    The operations phase of the Kepler mission is managed for NASA by the Ames Research Center, Moffett Field, CA. NASA’s Jet Propulsion Laboratory (JPL), Pasadena, CA, managed the mission through development, launch and the start of science operations. Dr. William Borucki of NASA Ames is the mission’s Science Principal Investigator. Ball Aerospace and Technologies Corp., Boulder, CO, developed the Kepler flight system.

    In October 2009, oversight of the Kepler project was transferred from the Discovery Program at NASA’s Marshall Space Flight Center, Huntsville, AL, to the Exoplanet Exploration Program at JPL

    K2

    Extending Kepler’s power to the ecliptic

    The loss of a second of the four reaction wheels on board the Kepler spacecraft in May 2013 brought an end to Kepler’s four plus year science mission to continuously monitor more than 150,000 stars to search for transiting exoplanets. Developed over the months following this failure, the K2 mission represents a new concept for spacecraft operations that enables continued scientific observations with the Kepler space telescope. K2 became fully operational in June 2014 and is expected to continue operating until 2017 or 2018.

    NASA image

    NASA JPL Icon

     
  • richardmitnick 4:06 pm on March 21, 2016 Permalink | Reply
    Tags: , , Caught For The First Time: The Early Flash Of An Exploding Star, NASA Kepler,   

    From Kepler and K2: “Caught For The First Time: The Early Flash Of An Exploding Star” 

    NASA Kepler Logo

    NASA Kepler Telescope
    NASA/Kepler

    March 21, 2016
    Michele Johnson
    Ames Research Center, Moffett Field, Calif.
    650-604-6982
    michele.johnson@nasa.gov

    The brilliant flash of an exploding star’s shockwave—what astronomers call the “shock breakout”—has been captured for the first time in the optical wavelength or visible light by NASA’s planet-hunter, the Kepler space telescope.

    An international science team led by Peter Garnavich, an astrophysics professor at the University of Notre Dame in Indiana, analyzed light captured by Kepler every 30 minutes over a three-year period from 500 distant galaxies, searching some 50 trillion stars. They were hunting for signs of massive stellar death explosions known as supernovae.

    In 2011, two of these massive stars, called red supergiants, exploded while in Kepler’s view. The first behemoth, KSN 2011a, is nearly 300 times the size of our sun and a mere 700 million light years from Earth. The second, KSN 2011d, is roughly 500 times the size of our sun and around 1.2 billion light years away.

    “To put their size into perspective, Earth’s orbit about our sun would fit comfortably within these colossal stars,” said Garnavich.

    Whether it’s a plane crash, car wreck or supernova, capturing images of sudden, catastrophic events is extremely difficult but tremendously helpful in understanding root cause. Just as widespread deployment of mobile cameras has made forensic videos more common, the steady gaze of Kepler allowed astronomers to see, at last, a supernova shockwave as it reached the surface of a star. The shock breakout itself lasts only about 20 minutes, so catching the flash of energy is an investigative milestone for astronomers.

    “In order to see something that happens on timescales of minutes, like a shock breakout, you want to have a camera continuously monitoring the sky,” said Garnavich. “You don’t know when a supernova is going to go off, and Kepler’s vigilance allowed us to be a witness as the explosion began.”

    Supernovae like these — known as Type II — begin when the internal furnace of a star runs out of nuclear fuel causing its core to collapse as gravity takes over.

    The two supernovae matched up well with mathematical models of Type II explosions reinforcing existing theories. But they also revealed what could turn out to be an unexpected variety in the individual details of these cataclysmic stellar events.

    While both explosions delivered a similar energetic punch, no shock breakout was seen in the smaller of the supergiants. Scientists think that is likely due to the smaller star being surrounded by gas, perhaps enough to mask the shockwave when it reached the star’s surface.

    “That is the puzzle of these results,” said Garnavich. “You look at two supernovae and see two different things. That’s maximum diversity.”

    Understanding the physics of these violent events allows scientists to better understand how the seeds of chemical complexity and life itself have been scattered in space and time in our Milky Way galaxy

    “All heavy elements in the universe come from supernova explosions. For example, all the silver, nickel, and copper in the earth and even in our bodies came from the explosive death throes of stars,” said Steve Howell, project scientist for NASA’s Kepler and K2 missions at NASA’s Ames Research Center in California’s Silicon Valley. “Life exists because of supernovae.”

    Garnavich is part of a research team known as the Kepler Extragalactic Survey or KEGS. The team is nearly finished mining data from Kepler’s primary mission, which ended in 2013 with the failure of reaction wheels that helped keep the spacecraft steady. However, with the reboot of the Kepler spacecraft as NASA’s K2 mission, the team is now combing through more data hunting for supernova events in even more galaxies far, far away.

    “While Kepler cracked the door open on observing the development of these spectacular events, K2 will push it wide open observing dozens more supernovae,” said Tom Barclay, senior research scientist and director of the Kepler and K2 guest observer office at Ames. “These results are a tantalizing preamble to what’s to come from K2!”

    In addition to Notre Dame, the KEGS team also includes researchers from the University of Maryland in College Park; the Australian National University in Canberra, Australia; the Space Telescope Science Institute in Baltimore, Maryland; and the University of California, Berkeley.

    The research paper reporting this discovery has been accepted for publication in the Astrophysical Journal.

    Authored by H. Pat Brennan/JPL and Michele Johnson/Ames

    See the full article here .

    Please help promote STEM in your local schools.

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    The Kepler Mission, NASA Discovery mission #10, is specifically designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone→ and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets.
    The operations phase of the Kepler mission is managed for NASA by the Ames Research Center, Moffett Field, CA. NASA’s Jet Propulsion Laboratory (JPL), Pasadena, CA, managed the mission through development, launch and the start of science operations. Dr. William Borucki of NASA Ames is the mission’s Science Principal Investigator. Ball Aerospace and Technologies Corp., Boulder, CO, developed the Kepler flight system.

    In October 2009, oversight of the Kepler project was transferred from the Discovery Program at NASA’s Marshall Space Flight Center, Huntsville, AL, to the Exoplanet Exploration Program at JPL

    K2

    Extending Kepler’s power to the ecliptic

    The loss of a second of the four reaction wheels on board the Kepler spacecraft in May 2013 brought an end to Kepler’s four plus year science mission to continuously monitor more than 150,000 stars to search for transiting exoplanets. Developed over the months following this failure, the K2 mission represents a new concept for spacecraft operations that enables continued scientific observations with the Kepler space telescope. K2 became fully operational in June 2014 and is expected to continue operating until 2017 or 2018.

    NASA image

    NASA JPL Icon

     
  • richardmitnick 11:15 pm on January 14, 2016 Permalink | Reply
    Tags: , , , NASA Kepler,   

    From Ethan Siegel: “Kepler found its longest-period exoplanet ever” 

    Starts with a bang
    Starts with a Bang

    1.14.16
    Ethan Siegel

    Temp 1
    Image credit: NASA / Michele Johnson.

    And it didn’t even need a transit to do it!

    “Mars is much closer to the characteristics of Earth. It has a fall, winter, summer and spring. North Pole, South Pole, mountains and lots of ice. No one is going to live on Venus; no one is going to live on Jupiter.”
    -Buzz Aldrin

    The Kepler spacecraft was one of the most brilliant technical and scientific achievements of the 2010s.

    NASA Kepler Telescope
    NASA/Kepler

    By launching a telescope into space and pointing it at the same field-of-view of stars for years and years, collecting the light from each one continuously, it became sensitive to tiny, minuscule variations in the intensity of their starlight.

    2
    Image credit: Painting by Jon Lomberg, Kepler mission diagram added by NASA.

    There are a number of reasons the amount of light a star emits could vary in intensity: it could be an intrinsically variable star (like a Cepheid, RR Lyrae or Delta Scuti variable, among others), it could be an eclipsing binary star system (an example of an extrinsic variable star), where one star periodically slips behind the other, or it could be due to the most exciting reason of all: something is transiting in front of that star to block a fraction of its light.

    3
    Image credit: NASA Ames.

    Sometimes, the transiting object could be close by, like an asteroid or a Kuiper belt object.

    4
    Known objects in the Kuiper belt beyond the orbit of Neptune. (Scale in AU; epoch as of January 2015.)

    Other times, it could be more distant, like an interstellar object. But what Kepler’s built to look for, and what it’s particularly seeking, is planets around the stars it’s looking at. In order for this method to be successful, you need for a number of things to happen all at once:

    You need the planetary orbit to be so serendipitously aligned with the star and your spacecraft that the orbital path appears to transit across the disk of the star from your point of view.

    You need the ratio of the planet’s size to the star’s to be large enough that your spacecraft can measure the transit’s magnitude.
    And you need the planet to transit across the star’s surface more than once so that you can be sure it wasn’t a foreground object having nothing to do with the star system you’re observing.

    Even if every star out there had a Solar System like our own, all three of these things being true would be a relatively rare occurrence, so if you’re just searching blindly, you need lots of targets. Kepler began operation in late 2009, pointing at an area of the Milky Way containing about 150,000 stars it was sensitive to. It measured the light from those stars over a long period of time — years — and to date has found close to 10,000 planetary candidates using these criteria. Some of them turn out not to be planets after all, as lots of things can mimic a planetary signal.

    This is why, if you want to confirm an exoplanet candidate, you need a second, independent method to do so.

    5
    Image credit: ESO, under the Creative Commons Attribution 4.0 International License.

    Normally, we use the stellar wobble method. Every planet that orbits a star has a mass, and just as the star pulls the planet into an elliptical orbit around it, the planet adds a tiny elliptical motion to the star’s orbit as well. This doesn’t produce a perceptible change in the star’s position, but does produce a perceptible change in the wavelength of the light emitted from the star: a redshift or blueshift, as the star moves either away or towards you in its periodic dance.

    Over a thousand planetary systems discovered by Kepler have been confirmed by the stellar wobble method, including Kepler-56, which is a star that’s presently evolving into a red giant as its core runs out of hydrogen to burn. Two large, inner planets — one about the mass of Neptune and one about half the mass of Jupiter — were found around this system. The large masses and close-in orbits make these exactly the types of planets that Kepler can find most easily, and also the types of planets that can easily and quickly be confirmed via stellar wobble.

    6
    Image credit: NASA Ames/W. Stenzel, of the Kepler planetary candidates as of July 2015.

    Kepler’s no good at finding planets that are much farther out than Earth is from our Sun, since in order to build up a robust, quality signal, you need multiple transits (more is better) of the planet across the star, which is very hard to do for a planet like say, Jupiter in our Solar System, which has an orbital period of 12 years, especially if your spacecraft has only been up there since 2009. To make things even worse, your chances of having a good alignment with a planet that’s more distant from its parent star drops very quickly as you move away. There’s a reason that hot, inner worlds are so abundant with Kepler: they’re the easiest ones to find.

    But sometimes, you do your follow-up for the transiting planets (the ones Kepler easily finds), and when you look for the stellar wobble, you not only find it…

    7
    Image credit: D. Huber et al., Science 18 October 2013: Vol. 342 no. 6156 pp. 331–334; DOI: 10.1126/science.1242066.

    but you find something else. In the case of Kepler-56, the innermost planet (blue line) gives off a clear signal that can be teased out; the second large planet (red line, higher mass) gives off an even more prominent signal. Yet perhaps the most notable signal is just labeled “trend,” which you need to add to the two planetary signals to get the observed data. When this was first reported in 2013, it was assumed this was probably a planet, but more data was needed to know its orbital properties: mass and period. As first released this week at the American Astronomical Society’s annual meeting, Kepler-56 appears to have a third planet orbiting it — about six times the mass of Jupiter with a period of around three Earth-years — thanks to the work of Justin Otor, Benjamin Montet and John A. Johnson.

    8
    Image credit: Danny Barringer, of Justin Otor’s poster at AAS 227.

    Finally, one almost complete “wobble cycle” of the outer planet has been observed with the follow-up data, and it’s actually a planet that doesn’t transit the star from our line-of-sight. It turns out that Kepler really can’t find these outer worlds on its own, but the clues that Kepler provides, of where to look for planetary systems where the stellar wobble can teach you so much more, can lead us to discover massive, outer planets that we never would’ve known to look for otherwise. Where there’s smoke, you look for the fire; where there are inner worlds, look for the outer ones. If you see the steep rise or fall associated with a massive wobble, you just might break the record.

    This article was partially based on information obtained during the 227th American Astronomical Society meeting, some of which may be unpublished.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

     
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