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  • richardmitnick 5:28 pm on May 22, 2017 Permalink | Reply
    Tags: Astronomers Confirm Orbital Details of TRAPPIST-1h, , NASA Kepler K2   

    From JPL-Caltech: “Astronomers Confirm Orbital Details of TRAPPIST-1h” 

    NASA JPL Banner

    JPL-Caltech

    May 22, 2017
    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    elizabeth.landau@jpl.nasa.gov

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

    Written by Michele Johnson

    1
    This artist’s concept shows TRAPPIST-1h, one of seven Earth-size planets in the TRAPPIST-1 planetary system. NASA’s Kepler spacecraft, operating in its K2 mission, obtained data that allowed scientists to determine that the orbital period of TRAPPIST-1h is 19 days.Credit: NASA/JPL-Caltech

    NASA/Kepler Telescope

    Scientists using NASA’s Kepler space telescope identified a regular pattern in the orbits of the planets in the TRAPPIST-1 system that confirmed suspected details about the orbit of its outermost and least understood planet, TRAPPIST-1h.

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

    TRAPPIST-1 is only eight percent the mass of our sun, making it a cooler and less luminous star. It’s home to seven Earth-size planets, three of which orbit in their star’s habitable zone — the range of distances from a star where liquid water could pool on the surface of a rocky planet. The system is located about 40 light-years away in the constellation of Aquarius. The star is estimated to be between 3 billion and 8 billion years old.

    Scientists announced that the system has seven Earth-sized planets at a NASA press conference on Feb. 22. NASA’s Spitzer Space Telescope, the TRAPPIST (Transiting Planets and Planetesimals Small Telescope) in Chile and other ground-based telescopes were used to detect and characterize the planets. But the collaboration only had an estimate for the period of TRAPPIST-1h.

    NASA/Spitzer Telescope

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


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

    Astronomers from the University of Washington have used data from the Kepler spacecraft to confirm that TRAPPIST-1h orbits its star every 19 days. At six million miles from its cool dwarf star, TRAPPIST-1h is located beyond the outer edge of the habitable zone, and is likely too cold for life as we know it. The amount of energy (per unit area) planet h receives from its star is comparable to what the dwarf planet Ceres, located in the asteroid belt between Mars and Jupiter, gets from our sun.

    “It’s incredibly exciting that we’re learning more about this planetary system elsewhere, especially about planet h, which we barely had information on until now,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate at Headquarters in Washington. “This finding is a great example of how the scientific community is unleashing the power of complementary data from our different missions to make such fascinating discoveries.”

    “It really pleased me that TRAPPIST-1h was exactly where our team predicted it to be. It had me worried for a while that we were seeing what we wanted to see — after all, things are almost never exactly what you expect them to be in this field,” said Rodrigo Luger, doctoral student at UW in Seattle, and lead author of the study published in the journal Nature Astronomy. “Nature usually surprises us at every turn, but, in this case, theory and observation matched perfectly.”

    Orbital Resonance – Harmony Among Celestial Bodies

    Using the prior Spitzer data, the team recognized a mathematical pattern in the frequency at which each of the six innermost planets orbits their star. This complex but predictable pattern, called an orbital resonance, occurs when planets exert a regular, periodic gravitational tug on each other as they orbit their star.

    To understand the concept of resonance, consider Jupiter’s moons Io, Europa and Ganymede, which is the farthest out of the three. For every time Ganymede orbits Jupiter, Europa orbits twice and Io makes four trips around the planet. This 1:2:4 resonance is considered stable and if one moon were nudged off course, it would self-correct and lock back into a stable orbit. It is this harmonious influence between the seven TRAPPIST-1 siblings that keeps the system stable.

    These relationships, said Luger, suggested that by studying the orbital velocities of its neighboring planets, scientists could predict the exact orbital velocity, and hence also orbital period, of planet h, even before the Kepler observations. The team calculated six possible resonant periods for planet h that would not disrupt the stability of the system, but only one was not ruled out by additional data. The other five possibilities could have been observed in the Spitzer and ground-based data collected by the TRAPPIST team.

    “All of this”, Luger said, “indicates that these orbital relationships were forged early in the life of the TRAPPIST-1 system, during the planet formation process.”

    “The resonant structure is no coincidence, and points to an interesting dynamical history in which the planets likely migrated inward in lock-step,” said Luger. “This makes the system a great laboratory for planet formation and migration theories.”

    Worldwide Real-time Collaboration

    The Kepler spacecraft stared at the patch of sky home to the TRAPPIST-1 system from Dec. 15, 2016, to March 4, 2017. collecting data on the star’s minuscule changes in brightness due to transiting planets as part of its second mission, K2. On March 8, the raw, uncalibrated data was released to the scientific community to begin follow-up studies.

    The work to confirm TRAPPIST-1h’s orbital period immediately began, and scientists from around the world took to social media to share in real-time the new information gleaned about the star’s behavior and its brood of planets. Within two hours of the data release, the team confirmed its prediction of a 19-day orbital period.

    “Pulling results out of data is always stimulating, but it was a rare treat to watch scientists across the world collaborate and share their progress in near-real time on social media as they analyzed the data and identified the transits of TRAPPIST-1h,” said Jessie Dotson, project scientist for the K2 mission at NASA’s Ames Research Center in California’s Silicon Valley. “The creativity and expediency by which the data has been put to use has been a particularly thrilling aspect of K2’s community-focused approach.”

    TRAPPIST-1’s seven-planet chain of resonances established a record among known planetary systems, the previous holders being the systems Kepler-80 and Kepler-223, each with four resonant planets.

    The TRAPPIST-1 system was first discovered in 2016 by the TRAPPIST collaboration, and was thought to have just three planets at that time. Additional planets were found with Spitzer and ground-based telescopes. NASA’s Hubble Space Telescope is following up with atmospheric observations, and the James Webb Space Telescope will be able to probe potential atmospheres in further detail.

    NASA/ESA Hubble Telescope

    “This work was based on 1333 hrs of new observations gathered from the ground with the 60cm telescopes TRAPPIST-South (469 hrs) and TRAPPIST-North (202 hrs), the 8m Very Large Telescope (3 hrs), the 4.2m William Herschel telescope (26 hrs), the 4m UKIRT telescope (25 hrs), the 2m Liverpool telescope (50 hrs), and the 1m SAAO telescope (11 hrs), and from space with Spitzer (518 hrs).

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

    Trappist-North Telescope in Morocco

    ESO/VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    ING 4 meter William Herschel Telescope at Roque de los Muchachos Observatory on La Palma in the Canary Islands

    UKIRT, located on Mauna Kea, Hawai’i, USA as part of Mauna Kea Observatory

    2-metre Liverpool Telescope at La Palma in the Canary Islands

    SAAO 1.9 meter Telescope, at the SAAO observation station 15Kms from the small Karoo town of Sutherland in the Northern Cape, a 4-hour drive from Cape Town.

    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 Corp. 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:

    https://www.nasa.gov/kepler

    For more information about the TRAPPIST-1 system, visit:

    http://exoplanets.nasa.gov/trappist1

    See the full article here .

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    NASA JPL Campus

    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 8:47 am on January 9, 2017 Permalink | Reply
    Tags: And along came a Neptune-sized planet, , Hot-Neptune, K2:105 b, NASA Kepler K2   

    From astrobites: “And along came a Neptune-sized planet” 

    Astrobites bloc

    Astrobites

    Title: The K2-ESPRINT Project VI: K2-105 b, a Hot-Neptune around a Metal-rich G-dwarf
    Authors: N.Narita et al. 2017
    First Author’s Institution: Department of Astronomy, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
    Status: Accepted in the Publications of the Astronomical Society of Japan, open access

    At the end of its extended 4 year campaign in space, Kepler scientists were left with a telescope that despite certain limitations, could still do good science. Thus the K2 mission was born and has so far found an additional 520 candidate exoplanets, including K2:105 b: a “Hot-Neptune” orbiting around a Sun-like G2 star. In this astrobite we will be discussing the K2 mission, confirming candidate planets using ground based telescopes and the importance of objects like K2-105 b if we are ever going to understand our own Solar system.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    1
    Fig 1: The observation fields for Kepler, including Field 5 which contains K2-105b. Credit: Kepler mission, NASA.

    Launched in 2009, Kepler spent four years watching hundreds of thousands of stars in order to catch transiting exoplanets. When a planet moves in front of its host, a characteristic dip in brightness is observed which is related to the radius of the exoplanet. The mission almost came to an end when the second of Kepler’s four reaction wheels ceased operations limiting control over its orientation. Thankfully the clever scientists at NASA concluded that Kepler could still be manoeuvred sufficiently to observe stars in one patch of the sky for 80 days. This gave rise to the K2 mission and provided scientists with a chance to continue their hunt for new planets.

    As of December the 21st 2016, the number of confirmed exoplanets sits at a staggering 3,439 planets, with some existing inside 576 confirmed planetary systems. Yet with over a thousand potential Kepler planets there is clearly still a lot of work to do on the ground. Kepler candidate planets are often confirmed through follow up observations of a stars wobble – this is known as the radial velocity method and when combined with transit data reveals the mass of an exoplanet.

    2
    Fig 2: (Left. Fig.1 of paper) Light curve of K2-105 taken by Kepler, with red bars to indicate the positions of transits, required to determine the radius of K2-105 b. (Right. Fig.6 of paper) Radial velocity data, taken with the Subaru telescope based in Hawaii, is combined with transit data to estimate the mass of K2-105 b.

    With a Neptune-like radius of around 23,000 km and orbital period of 8.27 days around its Sun-like host, K2-105 b is described as a Hot-Neptune. Hot-Neptunes are Neptune-sized planets with a radius between 3-6 times that of the Earth which orbit close to their star. Previous studies have only uncovered a few Hot-Neptunes around solar mass stars, and no exoplanets larger than Hot-Neptunes around smaller stars. This has lead some scientists to hypothesise the existence of a size boundary which planets must exceed to become a gas giant like Jupiter – meaning future investigation of Hot-Neptunes like K2-105 b are vital to understanding the formation of our outer Solar system.

    One major aspect for further study is uncovering the mass of K2-105 b. Some parameters were not extracted from the original radial velocity data, meaning current mass estimates are poorly constrained at 30 +/- 19 Earth masses. If the total mass is fewer than 30 Earth masses, scientists believe that the planet is likely to be a rocky planet with around 10% of its mass existing as an atmosphere – a kind of gas dwarf planet. This conclusion just leads to more questions such as how does a gas dwarf form? All current formation scenarios require the planetary mass to be known and this requires more radial velocity data.

    Observations of Hot-Neptunes could provide a good insight into the early days of Solar system formation. Clearly we have no K2-105 bs in our Solar system, and our own icy giants, Neptune and Uranus, are located beyond 20 AU. During the formation of a planetary system, planets are believed to migrate inwards towards their host star. The ‘Nice’ model suggests Saturn and Jupiter migrated inwards and not only acted as a barrier for icy giant inward migration, but also pushed Neptune and Uranus outwards to a highly elliptical orbit. Continued radial velocity observations will not only help constrain the mass of K2-105 b, but will also confirm whether the exoplanet has company in the form of outer planets.

    The Kepler spacecraft has discovered and confirmed thousands of exoplanets since its launch, providing scientists with new insights into just how odd and unique our own Solar system is. Hopefully K2-105 b is just the start of a Hot-Neptune discovering extravaganza required to uncover its early secrets.

    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 9:12 am on October 31, 2016 Permalink | Reply
    Tags: , , NASA Kepler K2, NASA Missions Harvest a Passel of ‘Pumpkin’ Stars,   

    From Goddard: “NASA Missions Harvest a Passel of ‘Pumpkin’ Stars” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Oct. 27, 2016
    Francis Reddy
    francis.j.reddy@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    Astronomers using observations from NASA’s Kepler and Swift missions have discovered a batch of rapidly spinning stars that produce X-rays at more than 100 times the peak levels ever seen from the sun. The stars, which spin so fast they’ve been squashed into pumpkin-like shapes, are thought to be the result of close binary systems where two sun-like stars merge.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    NASA/SWIFT Telescope
    NASA/SWIFT Telescope


    Access mp4 video here .
    Dive into the Kepler field and learn more about the origins of these rapidly spinning stars.
    Credits: Credits: NASA’s Goddard Space Flight Center/Scott Wiessinger, producer

    “These 18 stars rotate in just a few days on average, while the sun takes nearly a month,” said Steve Howell, a senior research scientist at NASA’s Ames Research Center in Moffett Field, California, and leader of the team. “The rapid rotation amplifies the same kind of activity we see on the sun, such as sunspots and solar flares, and essentially sends it into overdrive.”

    The most extreme member of the group, a K-type orange giant dubbed KSw 71, is more than 10 times larger than the sun, rotates in just 5.5 days, and produces X-ray emission 4,000 times greater than the sun does at solar maximum.

    2
    This artist’s concept illustrates how the most extreme “pumpkin star” found by Kepler and Swift compares with the sun. Both stars are shown to scale. KSw 71 is larger, cooler and redder than the sun and rotates four times faster. Rapid spin causes the star to flatten into a pumpkin shape, which results in brighter poles and a darker equator. Rapid rotation also drives increased levels of stellar activity such as starspots, flares and prominences, producing X-ray emission over 4,000 times more intense than the peak emission from the sun. KSw 71 is thought to have recently formed following the merger of two sun-like stars in a close binary system. Credits: NASA’s Goddard Space Flight Center/Francis Reddy

    These rare stars were found as part of an X-ray survey of the original Kepler field of view, a patch of the sky comprising parts of the constellations Cygnus and Lyra. From May 2009 to May 2013, Kepler measured the brightness of more than 150,000 stars in this region to detect the regular dimming from planets passing in front of their host stars. The mission was immensely successful, netting more than 2,300 confirmed exoplanets and nearly 5,000 candidates to date. An ongoing extended mission, called K2, continues this work in areas of the sky located along the ecliptic, the plane of Earth’s orbit around the sun.

    “A side benefit of the Kepler mission is that its initial field of view is now one of the best-studied parts of the sky,” said team member Padi Boyd, a researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who designed the Swift survey. For example, the entire area was observed in infrared light by NASA’s Wide-field Infrared Survey Explorer, and NASA’s Galaxy Evolution Explorer observed many parts of it in the ultraviolet.

    NASA/Galex telescope
    NASA/Galex telescope

    “Our group was looking for variable X-ray sources with optical counterparts seen by Kepler, especially active galaxies, where a central black hole drives the emissions,” she explained.

    Using the X-ray and ultraviolet/optical telescopes aboard Swift, the researchers conducted the Kepler–Swift Active Galaxies and Stars Survey (KSwAGS), imaging about six square degrees, or 12 times the apparent size of a full moon, in the Kepler field.

    “With KSwAGS we found 93 new X-ray sources, about evenly split between active galaxies and various types of X-ray stars,” said team member Krista Lynne Smith, a graduate student at the University of Maryland, College Park who led the analysis of Swift data. “Many of these sources have never been observed before in X-rays or ultraviolet light.”

    For the brightest sources, the team obtained spectra using the 200-inch telescope at Palomar Observatory in California.

    Caltech Palomar 200 inch Hale Telescope, at Mt Wilson, CA, USA
    Caltech Palomar 200 inch Hale Telescope interior
    Caltech Palomar 200 inch Hale Telescope, at Mt Wilson, CA, USA

    These spectra provide detailed chemical portraits of the stars and show clear evidence of enhanced stellar activity, particularly strong diagnostic lines of calcium and hydrogen.

    The researchers used Kepler measurements to determine the rotation periods and sizes for 10 of the stars, which range from 2.9 to 10.5 times larger than the sun. Their surface temperatures range from somewhat hotter to slightly cooler than the sun, mostly spanning spectral types F through K. Astronomers classify the stars as subgiants and giants, which are more advanced evolutionary phases than the sun’s caused by greater depletion of their primary fuel source, hydrogen. All of them eventually will become much larger red giant stars.

    A paper detailing the findings will be published in the Nov. 1 edition of the Astrophysical Journal and is now available online.

    Forty years ago, Ronald Webbink at the University of Illinois, Urbana-Champaign noted that close binary systems cannot survive once the fuel supply of one star dwindles and it starts to enlarge. The stars coalesce to form a single rapidly spinning star initially residing in a so-called “excretion” disk formed by gas thrown out during the merger. The disk dissipates over the next 100 million years, leaving behind a very active, rapidly spinning star.

    Howell and his colleagues suggest that their 18 KSwAGS stars formed by this scenario and have only recently dissipated their disks. To identify so many stars passing through such a cosmically brief phase of development is a real boon to stellar astronomers.

    “Webbink’s model suggests we should find about 160 of these stars in the entire Kepler field,” said co-author Elena Mason, a researcher at the Italian National Institute for Astrophysics Astronomical Observatory of Trieste. “What we have found is in line with theoretical expectations when we account for the small portion of the field we observed with Swift.”

    The team has already extended their Swift observations to additional fields mapped by the K2 mission.

    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 Corp. operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

    Goddard manages the Swift mission in collaboration with Pennsylvania State University in University Park, the Los Alamos National Laboratory in New Mexico and Orbital Sciences Corp. in Dulles, Virginia. Other partners include the University of Leicester and Mullard Space Science Laboratory in the United Kingdom, Brera Observatory and the Italian Space Agency in Italy, with additional collaborators in Germany and Japan.

    Related Links

    NASA’s Kepler and K2 mission website
    NASA’s Swift mission website

    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.
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  • richardmitnick 12:27 pm on October 24, 2016 Permalink | Reply
    Tags: Kepler has caught hundreds of asteroids, NASA Kepler K2,   

    From phys.org: “Kepler has caught hundreds of asteroids” 

    physdotorg
    phys.org

    October 24, 2016
    László Molnár

    1
    A selection of Trojan light curves. The shape of the light curve depends on the shape of the asteroid and its altitude with respect to the Sun. Asteroid (22056) appears to be a binary object with a period of almost fifteen days (lower right). Credit: Gy. M. Szabó et al. 2016

    Previously, the Kepler space telescope looked straight out from the solar system in a direction almost perpendicular to the ecliptic and the plane of the planets.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    This way, it could observe the same spot all year long, as the sun, and most of the solar system, were out of its field of view. But since the start of K2 mission, it has been observing parallel to that plane in order to better balance against the radiation pressure of the sun. This new strategy has two important consequences: One is that Kepler has to change its field of view every three months to avoid the sun; the other is that our own solar system, unexpectedly, has become a target for the exoplanet-hunting telescope.

    For most astronomers working with Kepler, planets and asteroids zipping through the images are little more than a nuisance when studying the light variations of stars. Researchers from the Konkoly and Gothard Observatories in Hungary, however, saw a research opportunity in these moving specks of light. Following up on their work with trans-Neptunian objects, they examined the light variations of some main-belt and Trojan asteroids in a pair of research papers.

    Szabó, R., et al: Uninterrupted optical light curves of main-belt asteroids from the K2 Mission, Astronomy & Astrophysics (2016), dx.doi.org/10.1051/0004-6361/201629059, arxiv.org/abs/1609.02759

    Szabó, Gy. M., et al.: The heart of the swarm: K2 photometry and rotational characteristics of 56 Jovian Trojan asteroids, Astronomy & Astrophysics (2016), doi.org/10.1051/0004-6361/201629401, arxiv.org/abs/1609.02760

    They used a custom-built pipeline based on the software package Fitsh, developed by team member András Pál, to accurately measure moving targets in the images.

    Main-belt asteroids were not targeted by Kepler, so the astronomers selected two extended mosaics that covered the open cluster M35 and the path of the planet Neptune, and simply tracked all known asteroids crossing them. Most of the objects were continuously observable for one to four days, which may not sound like much, but is significantly longer than single-night runs achievable with ground-based telescopes. Indeed, the researchers hoped that with Kepler, they could determine the rotation periods of the asteroids more accurately, without the uncertainties caused by daytime gaps in the data—and they did, but only for a fraction of the sample.

    “We measured the paths of all known asteroids, but most of them turned out to be simply too faint for Kepler. The dense stellar background toward M35 further reduced the number of successful detections,” said Róbert Szabó (Konkoly Observatory, MTA CSFK), lead author of the paper. “Still, we have to keep in mind that Kepler was never meant to do such studies; therefore, observing four dozen asteroids with new rotation rates is already more than anybody anticipated,” he added.

    The other study focused on 56 pre-selected Trojan asteroids in the middle of the L4, or “Greek” group, which orbits ahead of Jupiter. Since they are farther out from Kepler, they could be observed for longer periods, from 10 to 20 days, without interruption. And this turned out to be crucial: Many objects exhibited slow light variations between two and 15 days. Long periodicity suggests that what we see is not just one rotating asteroid, but actually two orbiting each other—the study confirmed that about 20 to 25 percent of Trojans are binary asteroids or asteroid-moon pairs. As Gyula M. Szabó (ELTE Gothard Astrophysical Observatory), lead author of the other paper, said, “Estimating the rate of binaries highlights the great advantage of Kepler, because the interesting periods, longer than 24 to 48 hours, are really hard to measure from the Earth.”

    What Kepler did not see are rapidly spinning Trojans. Even for the fastest ones, one rotation takes more than five hours, suggesting that the asteroids we see are likely icy, porous objects, similar to comets and trans-Neptunian objects, and different from the rockier main belt objects. “A large piece of rock can rotate much faster than a rubble pile or an icy body of the same size without breaking apart. Our findings favour the scenario that Trojans arrived from the ice-dominated outer solar system instead of migrating outwards from the main asteroid belt,” Szabó said.

    3
    Kepler aimed at the heart of the L4 swarm. Green dots are the known Trojans, black dots are the observed ones. Credit: Gy. M. Szabó et al. 2016

    As Kepler continues its new mission, more objects from the solar system are crossing into its view, including planets, moons, asteroids and comets. The telescope that transformed the science of stars and exoplanets will undoubtedly leave its mark in planetary science, as well.

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page. set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 8:13 am on October 24, 2016 Permalink | Reply
    Tags: , , Kepler finds scores of planets around cool dwarf stars, NASA Kepler K2,   

    From Nature: “Kepler finds scores of planets around cool dwarf stars” 

    Nature Mag
    Nature

    21 October 2016
    Ramin Skibba

    1
    NASA Ames/JPL-Caltech/T Pyle

    NASA’s Kepler observatory has spotted 20 planets that orbit cool, small stars — the largest such haul so far. These long-lived stars, known as K and M dwarfs, are ubiquitous in the Milky Way and could turn out to host numerous habitable planets.

    After the Kepler spacecraft experienced a mechanical failure in 2013 that made it impossible for it to keep observing its original targets, astronomers gave it a new mission, called K2. It now uses pressure from sunlight to help stabilize the craft. The latest observations with K2 revealed 87 planet candidates, on top of 667 previously announced candidates, almost all with sizes between those of Mars and Neptune.

    Although the original Kepler mission examined many Sun-like stars, the majority of stars in our Galaxy are smaller, fainter, cooler stars, known as red dwarfs. Such stars make up nearly half the targets of the K2 mission. “There are more than 250 of them within 30 light-years — all over the place — which is why some other astronomers here might call them the vermin of the sky,” says Courtney Dressing, an astrophysicist at the California Institute of Technology in Pasadena who presented the research at a joint meeting of the American Astronomical Society’s Division for Planetary Sciences and the European Planetary Science Congress in Pasadena on 19 October.

    Of the confirmed planets, 63 are smaller than Neptune, and a few could be even smaller than Earth. But these small candidates remain to be confirmed. Dressing believes that these are probably “false positives” caused by other phenomena such as cosmic rays or an instrumental glitch.

    Five of the confirmed planet candidates are in or near their star’s ‘habitable zone’, the region that’s neither too close to the star, nor too far from it, for life to arise. In our Solar System, the zone is roughly between the orbits of Venus and Mars.

    Red dwarf stars give off less energy than larger, hotter stars, so their planets’ habitable zones are closer in, often closer to their star than Mercury is to the Sun. Such planets transit frequently, some orbiting their star within just a few weeks, making it easier to use Kepler’s instruments to detect the tell-tale dimming of stellar light.

    The focus on red dwarfs stems partly from the K2 mission’s constraints, which allow the astronomers less then three months to observe stars in its field of viewbefore having to rotate the craft. Moving from field to field poses a challenge, but it also gives the team an opportunity to investigate more objects. “It’s fun to study a new set of stars every 80 days,” Dressing says.

    Dressing’s research also paves the way for more sensitive future missions designed to look for Earth-sized planets, says Christa van Laerhoven, a planetary scientist at the Canadian Institute for Theoretical Astrophysics in Toronto. Such missions include NASA’s Transiting Exoplanet Survey Satellite, scheduled to launch in December next year.

    NASA/TESS
    NASA/TESS

    See the full article here .

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    Nature is a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature also provides rapid, authoritative, insightful and arresting news and interpretation of topical and coming trends affecting science, scientists and the wider public.

     
  • richardmitnick 1:49 pm on July 18, 2016 Permalink | Reply
    Tags: , , , , NASA Kepler K2   

    From Keck: “More Than 100 Planets Confirmed in Single Trove” 

    Keck Observatory

    Keck Observatory.
    Keck, with Subaru and IRTF (NASA Infrared Telescope Facility). Vadim Kurland

    Keck Observatory

    MEDIA CONTACT

    Steve Jefferson
    W. M. Keck Observatory
    (808) 881-3827
    sjefferson@keck.hawaii.edu

    MEDIA CONTACT

    Ian Crossfield
    University of Arizona
    (949) 923-0578
    ianc@lpl.arizona.edu

    1
    An artist’s impression of Kepler-78b, an Earth-sized rocky exoplanet discovered by Roberto Sanchis-Ojeda (MIT) using Kepler Space Telescope data, and confirmed by University of Hawaii astronomer Andrew Howard using W. M. Keck Observatory atop Mauna Kea. Courtesy of UH-Manoa.

    An international team of astronomers have discovered and confirmed a treasure trove of new worlds. The researchers achieved this extraordinary discovery of exoplanets by combining NASA’s K2 mission data with follow-up observations by Earth-based telescopes including the W. M. Keck Observatory on Maunakea, the twin Gemini telescopes on Maunakea and in Chile, the Automated Planet Finder of the University of California Observatories and the Large Binocular Telescope operated by the University of Arizona. The team confirmed more than 100 planets, including the first planetary system comprising four planets potentially similar to Earth. The discoveries are published online in The Astrophysical Journal Supplement Series.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    Gemini/North telescope at Manua Kea, Hawaii, USA
    Gemini/North telescope at Manua Kea, Hawaii, USA

    Gemini South telescope
    Gemini South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile

     UCO Lick Automated Planet Finder telescope
    UCO Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA

    Large Binocular Telescope,  Mount Graham,  Arizona, USA
    U Arizona Large Binocular Telescope, Mount Graham, Arizona, USA

    Ironically, the bounty was made possible when the Kepler space telescope’s pointing system broke.

    In its initial mission, Kepler surveyed a specific patch of sky in the northern hemisphere, measuring the frequency with which planets whose sizes and temperatures are similar to Earth occur around stars like our sun. But when it lost its ability to precisely stare at its original target area in 2013, engineers created a second life for the telescope that is proving remarkably fruitful.

    The new mission, dubbed K2, has provided the capability of observing a series of independent target fields in the ecliptic plane with greater opportunities for Earth-based observatories in both the northern and southern hemispheres. Additionally, in contrast to the Kepler mission, K2 is an entirely community-driven mission with all targets proposed for by the scientific community. K2 now looks at a larger fraction of cooler, smaller, red dwarf-type stars, which are much more common in our Milky Way than sun-like stars.

    “Kepler’s original mission observed a small patch of sky as it was designed to conduct a demographic survey of the different types of planets,” said Ian Crossfield, a Sagan Fellow at the University of Arizona’s Lunar and Planetary Laboratory, who led the research effort. “This approach effectively meant that relatively few of the brightest, closest red dwarfs were included in Kepler’s survey. The K2 mission allows us to increase the number of small, red stars by a factor of 20 for further study.”

    One of the most interesting set of planets discovered in this study is a system of four potentially rocky planets, between 20 and 50 percent larger than Earth, orbiting a star less than half the size and with less light output than the Sun. Their orbital periods range from five-and-a-half to 24 days, and two of them may experience radiation levels from their star comparable to those on Earth.

    Despite their tight orbits — closer than Mercury’s orbit around the sun — the possibility that life could arise on a planet around such a star cannot be ruled out, according to Crossfield.

    “Because these smaller stars are so common in the Milky Way, it could be that life occurs much more frequently on planets orbiting cool, red stars rather than planets around stars like our sun,” Crossfield said.

    To validate candidate planets identified by K2, the researchers obtained high-resolution images of the planet-hosting stars from Keck Observatory’s near infrared camera (NIRC2), the Gemini and Large Binocular Telescope (among others) as well as high-resolution optical spectroscopy using Keck Observatory’s high resolution spectrograph (HIRES) instrument and the AUtomated Planet Finder. By dispersing the starlight, the spectrographs allowed the researchers to measure the physical properties of a star — such as mass, radius and temperature — and infer the properties of any planets orbiting it.

    Keck NIRC2 Camera
    Keck NIRC2 Camera

    Keck HIRES
    Keck HIRES

    “Our analysis shows that by the end of the K2 mission, we expect to double or triple the number of relatively small planets orbiting nearby, bright stars,” Crossfield said. “And because these planets orbit brighter stars, we’ll be able to more easily study everything possible about them, whether it’s measuring their masses with Doppler spectroscopy — already underway at Keck Observatory and APF — or measuring their atmospheric makeup with the James Webb Space Telescope in just a few years.”

    For a full list of authors and funding information, please see the research paper, “197 Candidates and 104 Validated Planets in K2’s First Five Fields,” available for download at https://www.lpl.arizona.edu/~ianc/docs/crossfield….

    NIRC2 (the Near-Infrared Camera, second generation) works in combination with the Keck II adaptive optics system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other stars, and study detailed morphology of distant galaxies.

    HIRES (the High-Resolution Echelle Spectrometer) produces spectra of single objects at very high spectral resolution, yet covering a wide wavelength range. It does this by separating the light into many “stripes” of spectra stacked across a mosaic of three large CCD detectors. HIRES is famous for finding planets orbiting other stars. Astronomers also use HIRES to study distant galaxies and quasars, finding clues to the Big Bang. 


    See the full article here .

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    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.
    Keck UCal

    Keck NASA

    Keck Caltech

     
  • richardmitnick 1:08 pm on May 30, 2016 Permalink | Reply
    Tags: , , , NASA Kepler K2, The Promise of Kepler-62f: A Distant Earth-like World   

    From CosmosUp: “The Promise of Kepler-62f: A Distant Earth-like World” 

    CosmosUp bloc

    CosmosUp

    30, May 2016

    On April 18, 2013, NASA’ astronomers announced the discovery of a new planetary system composed of five worlds orbiting a star somewhat cooler and smaller than the Sun, approximately 1,200 light-years away from us in the constellation Lyra.

    The outermost of them, named Kepler-62f, looks hopeful for supporting life. Around 40% larger than our planet, Kepler-62f is likely a solid planet within the star’s habitable zone, where conditions may be just right for liquid water to form.

    Giving its good shape and size, the unique planet may even possess surface oceans, but back then, NASA’s Kepler mission failed to gather sufficient information about Kpler-62f’ composition, atmosphere or orbit.

    At that size, Kepler-62f is within the range of planets that are likely to be rocky and possibly could have oceans,

    said Aomawa Shields, lead author of the study published* in the May 13 issue of the journal Astrobiology.

    So, to determine whether Kepler-62f could harbor life, Aomawa Shields ran computer simulations and thus came up with various scenarios of possible atmospheric conditions and orbital shape of the planet.

    “We found there are multiple atmospheric compositions that allow it to be warm enough to have surface liquid water. This makes it a strong candidate for a habitable planet.”

    4
    Kepler 62f. NASA

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    On Earth, carbon dioxide makes up about 0.04% of the atmosphere. Because Kepler-62f is much farther from its parent star than Earth is to the Sun, it would need a thick carbon dioxide-rich atmosphere to stop its water from freezing — it needs to have three to five times a thicker atmosphere than the Earth’s in order to be considered consistently habitable during the entire year.

    But, what if the carbon-dioxide levels are low or closer to those found on Earth? Shields estimated the temperature on the planet rises above freezing during certain times of the year which may result in melting of the ice sheets to form liquid water – enough to sustain life.

    Though astronomers don’t know for sure whether life could exist on Kepler-62f, but Dr Shields is optimistic about finding life in the universe.

    “This technique will help us understand how likely certain planets are to be habitable over a wide range of factors, for which we don’t yet have data from telescopes,

    she said.

    And it will allow us to generate a prioritized list of targets to follow up on more closely with the next generation of telescopes that can look for the atmospheric fingerprints of life on another world.”

    Kepler-62f and Kepler’ Legacy

    To date, NASA’ Kepler Telescope has discovered more than 2300 exoplanets and more than twice are as-yet unconfirmed planetary candidates, but only few are considered to belong in the “habitable zone” — the range of orbits around a star within which a planetary surface can support liquid water.

    The most habitable planet to date is Kepler-452b but it is located 1,400 light-years away from us, so unless we invent a way of prolonging our lives drastically, it might remain a pipe dream for now.

    But there are others relatively close planets to us that could be habitable, like Gliese 581d which is just 20 light years away; who knows, maybe soon we could detect exoplanets even closer than Gliese 581d, maybe there’s a planet in Alpha Centauri star system waiting for us to be discovered, or within the range of 10 ly from us.

    Whether or not intelligent life actually exists in our universe, we know for sure there is life out there and we are getting closer and closer to find it.

    Science paper:
    The Effect of Orbital Configuration on the Possible Climates and Habitability of Kepler-62f

    See the full article here .

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  • richardmitnick 7:31 pm on May 11, 2016 Permalink | Reply
    Tags: , , , NASA Kepler K2, What Are The Odds Of Finding Earth 2.0?   

    From Ethan Siegel: “What Are The Odds Of Finding Earth 2.0?” 

    May 10, 2016
    Ethan Siegel

    1
    The exoplanet Kepler-452b (R), as compared with Earth (L), a possible candidate for Earth 2.0. Image credit: Image credit: NASA/Ames/JPL-Caltech/T. Pyle.

    Just a short 25 years ago, if you had asked astronomers and astrophysicists whether there were planets around other stars, the answer would have been, “probably, but we don’t know for sure.” Thanks to a number of new techniques and advanced equipment, we’ve now discovered thousands of stars within our own galaxy that have their own Solar System. Planets come in a huge diversity of sizes and masses, and are found at all sorts of orbital distances; there are planets larger than Jupiter that orbit their star in less than 48 hours, there are Solar Systems with up to five planets interior to where Mercury is to our Sun, and there are over 200 Earth-sized planets discovered around those stars so far, plus 21 rocky worlds in the habitable zones of their stars.

    2
    The 21 Kepler planets discovered in the habitable zones of their stars, no larger than twice the Earth’s diameter. Image credit: NASA Ames/N. Batalha and W. Stenzel.

    Almost all of this information came from NASA’s Kepler mission, which has been the primary exoplanet-discovering tool at our disposal.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    Yesterday marked the transit of Mercury, where our Solar System’s innermost planet passed in front of the Sun’s disk, blocking its light for a short period of time.

    Planet transit. NASA
    Planet transit. NASA

    At the start of a transit, the star’s brightness drops by whatever portion of the star’s disk is covered, then increases again when the planet moves off. That apparent dip in the star’s brightness, as tiny as it is, provides us with the very method that Kepler uses to detect planets around stars other than our own. When a planetary system is perfectly aligned with a star, relative to our line-of-sight, we can observe this transit, and detect worlds around another star.

    The Kepler spacecraft observed a field of view containing approximately 150,000 stars over a period of approximately four years, detecting more than 2,000 planets and with over 1,000 additional “likely planets” that are still awaiting confirmation. But that doesn’t mean that only 1%-2% of stars have planets around them; the likelihood of having a good planetary alignment with our line-of-sight is very low, and furthermore, we can only detect planets with orbital periods that are less than Kepler’s observing time, so nothing farther out than Mars is.

    3
    The planets discovered around other stars, by year. Image credit: NASA Ames/W. Stenzel; Princeton University/T. Morton.

    When we compare what we’ve seen with what we expect to be there from the things we cannot yet see, we find some incredible things:

    About 80% of star systems are expected to have planets around them,
    The vast majority of planets are three times the size of Earth or smaller, not gas giant worlds,
    And that it’s estimated that there are approximately 60 billion rocky, habitable-zone planets in our galaxy alone.

    4
    The number of planets, by size, of all known exoplanets. Just under half of them are rocky worlds, which are the most difficult type to detect. Image credit: NASA Ames/W. Stenzel.

    But there is a big different between a potentially habitable planet as we define it — a rocky planet at the right distance from its star that, with Earth-like atmospheric conditions, it would have liquid water on its surface — and a planet that’s capable of being a home for humans: a true Earth 2.0. Because what we need is much more specific than that. Sure, we need a rocky, habitable-zone planet, but we also need:

    A planet without just the ingredients for life (which all rocky ones should have) but where life actually took off,
    Where no catastrophes stopped it altogether, but where it evolved into complex, diverse, multicellular organisms,
    And where, perhaps with only minor adaptations, we could survive and thrive on the surface.

    If we get really, really lucky, we’d find a bonus step in there as well: where one of those complex lifeforms became a technologically advanced civilization, as we’re still in the process of becoming. How likely is it that there’s another planet in the galaxy where all that has happened? Or in the entire Universe? While we don’t yet know, there is something very intelligent we can say about it.

    5
    Image credit: A. Frank and W.T. Sullivan III, Astrobiology 16, 3, (2016), via http://online.liebertpub.com/doi/pdf/10.1089/ast.2015.1418.

    According to research by Adam Frank and Woody Sullivan, if humanity isn’t a rarity in the Universe, that means that the probability of those three big steps — life takes off on a world, life evolves into complex organisms, and one such lifeform becomes technologically advanced — must be at least 2.5 × 10^-22, and if we’re not a rarity in the galaxy it must be at least 1.7 × 10^-11. But it could be much, much higher, particularly if we don’t require a technologically advanced civilization.

    According to research by Adam Frank and Woody Sullivan, if humanity isn’t a rarity in the Universe, that means that the probability of those three big steps — life takes off on a world, life evolves into complex organisms, and one such lifeform becomes technologically advanced — must be at least 2.5 × 10^-22, and if we’re not a rarity in the galaxy it must be at least 1.7 × 10^-11. But it could be much, much higher, particularly if we don’t require a technologically advanced civilization.

    See the full article here .

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    “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

     
  • richardmitnick 2:27 pm on May 11, 2016 Permalink | Reply
    Tags: 2007 OR10 largest unnamed body in our solar system, , , , NASA Kepler K2   

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

    NASA JPL Banner

    JPL-Caltech

    May 11, 2016
    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

    Konkoly Observatory at Piszkesteto Mountain Station, Hungary
    Konkoly Observatory Budapest Hungary
    Konkoly Observatory at Piszkesteto Mountain Station, Hungary

    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. 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.

    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.

    ESA Herschel
    ESA Herschel

    “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.

    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.

    Planet transit. NASA
    Planet transit. NASA

    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.

    “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

    *Science paper:
    LARGE SIZE AND SLOW ROTATION OF THE TRANS-NEPTUNIAN OBJECT (225088) 2007 OR10 DISCOVERED FROM HERSCHEL AND K2 OBSERVATIONS

    See the full article here .

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    NASA JPL Campus

    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 3:41 pm on May 10, 2016 Permalink | Reply
    Tags: , , NASA Kepler K2, NASA's Kepler Mission Announces Largest Collection of Planets Ever Discovered   

    From Kepler: “NASA’s Kepler Mission Announces Largest Collection of Planets Ever Discovered” 

    NASA Kepler Logo

    NASA Kepler Telescope
    NASA/Kepler

    May 10, 2016

    Felicia Chou
    Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov

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

    1
    This artist’s concept depicts select planetary discoveries made to date by NASA’s Kepler space telescope.Credits: NASA/W. Stenzel

    NASA’s Kepler mission has verified 1,284 new planets – the single largest finding of planets to date.

    “This announcement more than doubles the number of confirmed planets from Kepler,” said Ellen Stofan, chief scientist at NASA Headquarters in Washington. “This gives us hope that somewhere out there, around a star much like ours, we can eventually discover another Earth.”

    Analysis was performed on the Kepler space telescope’s July 2015 planet candidate catalog, which identified 4,302 potential planets. For 1,284 of the candidates, the probability of being a planet is greater than 99 percent – the minimum required to earn the status of “planet.” An additional 1,327 candidates are more likely than not to be actual planets, but they do not meet the 99 percent threshold and will require additional study. The remaining 707 are more likely to be some other astrophysical phenomena. This analysis also validated 984 candidates previously verified by other techniques.

    “Before the Kepler space telescope launched, we did not know whether exoplanets were rare or common in the galaxy. Thanks to Kepler and the research community, we now know there could be more planets than stars,” said Paul Hertz, Astrophysics Division director at NASA Headquarters. “This knowledge informs the future missions that are needed to take us ever-closer to finding out whether we are alone in the universe.”

    Kepler captures the discrete signals of distant planets – decreases in brightness that occur when planets pass in front of, or transit, their stars – much like the May 9 Mercury transit of our sun. Since the discovery of the first planets outside our solar system more than two decades ago, researchers have resorted to a laborious, one-by-one process of verifying suspected planets.

    Planet transit. NASA
    Planet transit. NASA

    This latest announcement, however, is based on a statistical analysis method that can be applied to many planet candidates simultaneously. Timothy Morton, associate research scholar at Princeton University in New Jersey and lead author of the scientific paper published* in The Astrophysical Journal, employed a technique to assign each Kepler candidate a planet-hood probability percentage – the first such automated computation on this scale, as previous statistical techniques focused only on sub-groups within the greater list of planet candidates identified by Kepler.

    “Planet candidates can be thought of like bread crumbs,” said Morton. “If you drop a few large crumbs on the floor, you can pick them up one by one. But, if you spill a whole bag of tiny crumbs, you’re going to need a broom. This statistical analysis is our broom.”

    In the newly-validated batch of planets, nearly 550 could be rocky planets like Earth, based on their size. Nine of these orbit in their sun’s habitable zone, which is the distance from a star where orbiting planets can have surface temperatures that allow liquid water to pool. With the addition of these nine, 21 exoplanets now are known to be members of this exclusive group.

    “They say not to count our chickens before they’re hatched, but that’s exactly what these results allow us to do based on probabilities that each egg (candidate) will hatch into a chick (bona fide planet),” said Natalie Batalha, co-author of the paper and the Kepler mission scientist at NASA’s Ames Research Center in Moffett Field, California. “This work will help Kepler reach its full potential by yielding a deeper understanding of the number of stars that harbor potentially habitable, Earth-size planets — a number that’s needed to design future missions to search for habitable environments and living worlds.”

    Of the nearly 5,000 total planet candidates found to date, more than 3,200 now have been verified, and 2,325 of these were discovered by Kepler. Launched in March 2009, Kepler is the first NASA mission to find potentially habitable Earth-size planets. For four years, Kepler monitored 150,000 stars in a single patch of sky, measuring the tiny, telltale dip in the brightness of a star that can be produced by a transiting planet. In 2018, NASA’s Transiting Exoplanet Survey Satellite will use the same method to monitor 200,000 bright nearby stars and search for planets, focusing on Earth and Super-Earth-sized.

    *Science paper:
    FALSE POSITIVE PROBABILITIES FOR ALL KEPLER OBJECTS OF INTEREST: 1284 NEWLY VALIDATED PLANETS AND 428 LIKELY FALSE POSITIVES

    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

    K2Extending 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.

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