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  • richardmitnick 10:33 pm on November 27, 2017 Permalink | Reply
    Tags: , , , , Hot Jupiters, , , Newly Discovered Twin Planets Could Solve Puffy Planet Mystery, University of Hawaii Institute for Astronomy   

    From Keck: “Newly Discovered Twin Planets Could Solve Puffy Planet Mystery” 

    Keck Observatory

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

    Keck Observatory

    November 27, 2017
    Sam Grunblatt
    skg3@hawaii.edu
    Cell: 845-430-4603

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    Office: 808-956-8573

    Dr. Roy Gal
    Media Contact
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    1
    Upper left: Schematic of the K2-132 system on the main sequence. Lower left: Schematic of the K2-132 system now. The host star has become redder and larger, irradiating the planet more and thus causing it to expand. Sizes not to scale. Main panel: Gas giant planet K2-132b expands as its host star evolves into a red giant. The energy from the host star is transferred from the planet’s surface to its deep interior, causing turbulence and deep mixing in the planetary atmosphere. The planet orbits its star every nine days and is located about 2000 light years away from us in the constellation Virgo.
    Hot Jupiters. Credit: KAREN TERAMURA, UH ©IFA/Hawaii.

    Since astronomers first measured the size of an extrasolar planet seventeen years ago, they have struggled to answer the question: how did the largest planets get to be so large?

    Thanks to the recent discovery of twin planets by a University of Hawaii Institute for Astronomy team led by graduate student Samuel Grunblatt, scientists are getting closer to an answer.

    Gas giant planets are primarily made out of hydrogen and helium, and are at least four times the diameter of Earth. Gas giant planets that orbit scorchingly close to their host stars are known as “hot Jupiters.” These planets have masses similar to Jupiter and Saturn, but tend to be much larger – some are puffed up to sizes even larger than the smallest stars.

    The unusually large sizes of these planets are likely related to heat flowing in and out of their atmospheres, and several theories have been developed to explain this process. “However, since we don’t have millions of years to see how a particular planetary system evolves, planet inflation theories have been difficult to prove or disprove,” said Grunblatt.

    To solve this issue, Grunblatt searched through data collected by NASA’s K2 Mission to hunt for hot Jupiters orbiting red giant stars. These stars, which are in the late stages of their lives, become themselves significantly larger over their companion planet’s lifetime. Following a theory put forth by Eric Lopez of NASA’s Goddard Space Flight Center, hot Jupiters orbiting red giant stars should be highly inflated if direct energy input from the host star is the dominant process inflating planets.

    The search has now revealed two planets, each orbiting their host star with a period of approximately nine days. Using stellar oscillations to precisely calculate the radii of both the stars and planets, the team found that the planets are 30 percent larger than Jupiter.

    Observations using the W. M. Keck Observatory on Maunakea, Hawaii also showed that, despite their large sizes, the planets were only half as massive as Jupiter. Remarkably, the two planets are near twins in terms of their orbital periods, radii, and masses.

    Using models to track the evolution of the planets and their stars over time, the team calculated the planets’ efficiency at absorbing heat from the star and transferring it to their deep interiors, causing the whole planet to expand in size and decrease in density. Their findings show that these planets likely needed the increased radiation from the red giant star to inflate, but the amount of radiation absorbed was also lower than expected.

    It is risky to attempt to reach strong conclusions with only two examples. But these results begin to rule out some explanations of planet inflation, and are consistent with a scenario where planets are directly inflated by the heat from their host stars. The mounting scientific evidence seems to suggest that stellar radiation alone can directly alter the size and density of a planet.

    Our own Sun will eventually become a red giant star, so it’s important to quantify the effect its evolution will have on the rest of the Solar System. “Studying how stellar evolution affects planets is a new frontier, both in other solar systems as well as our own,” said Grunblatt. “With a better idea of how planets respond to these changes, we can start to determine how the Sun’s evolution will affect the atmosphere, oceans, and life here on Earth.”

    The search for gas giant planets around red giant stars continues since additional systems could conclusively distinguish between planet inflation scenarios. Grunblatt and his team have been awarded time with the NASA Spitzer Space Telescope to measure the sizes of these twin planets more accurately. In addition, the search for planets around red giants with the NASA K2 Mission will continue for at least another year, and NASA’s Transiting Exoplanet Survey Satellite (TESS), launching in 2018, will observe hundreds of thousands of red giants across the entire sky.

    Seeing double with K2: Testing re-inflation with two remarkably similar planets orbiting red giant branch stars. published in November 27th edition of The Astronomical Journal.

    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.
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  • richardmitnick 2:11 pm on August 2, 2017 Permalink | Reply
    Tags: , , , , Hot Jupiters, Hubble Detects Exoplanet with Glowing Water Atmosphere, , WASP121b   

    From Hubble: “Hubble Detects Exoplanet with Glowing Water Atmosphere” 

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    NASA/ESA Hubble Telescope

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    Aug 2, 2017

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

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    1
    Scorching “Hot Jupiter” Has a Stratospheric Layer
    Only when we fly in a commercial jet at an altitude of about 33,000 feet do we enter Earth’s stratosphere, a cloudless layer of our atmosphere that blocks ultraviolet light. Astronomers were fascinated to find evidence for a stratosphere on a planet orbiting another star. As on Earth, the planet’s stratosphere is a layer where temperatures increase with higher altitudes, rather than decrease. However, the planet (WASP-121b) is anything but Earth-like. The Jupiter-sized planet is so close to its parent star that the top of the atmosphere is heated to a blazing 4,600 degrees Fahrenheit (2,500 degrees Celsius), hot enough to rain molten iron! This new Hubble Space Telescope observation allows astronomers to compare processes in exoplanet atmospheres with the same processes that happen under different sets of conditions in our own solar system.

    Scientists have discovered the strongest evidence to date for a stratosphere on a planet outside our solar system, or exoplanet. A stratosphere is a layer of atmosphere in which temperature increases with higher altitudes.

    “This result is exciting because it shows that a common trait of most of the atmospheres in our solar system — a warm stratosphere — also can be found in exoplanet atmospheres,” said Mark Marley, study co-author based at NASA’s Ames Research Center in California’s Silicon Valley. “We can now compare processes in exoplanet atmospheres with the same processes that happen under different sets of conditions in our own solar system.”

    Reporting in the journal Nature, scientists used data from NASA’s Hubble Space Telescope to study WASP-121b, a type of exoplanet called a “hot Jupiter.” Its mass is 1.2 times that of Jupiter, and its radius is about 1.9 times Jupiter’s — making it puffier. But while Jupiter revolves around our sun once every 12 years, WASP-121b has an orbital period of just 1.3 days. This exoplanet is so close to its star that if it got any closer, the star’s gravity would start ripping it apart. It also means that the top of the planet’s atmosphere is heated to a blazing 4,600 degrees Fahrenheit (2,500 degrees Celsius), hot enough to boil some metals. The WASP-121 system is estimated to be about 900 light-years from Earth — a long way, but close by galactic standards.

    Previous research found possible signs of a stratosphere on the exoplanet WASP-33b as well as some other hot Jupiters. The new study presents the best evidence yet because of the signature of hot water molecules that researchers observed for the first time.

    “Theoretical models have suggested stratospheres may define a distinct class of ultra-hot planets, with important implications for their atmospheric physics and chemistry,” said Tom Evans, lead author and research fellow at the University of Exeter, United Kingdom. “Our observations support this picture.”

    To study the stratosphere of WASP-121b, scientists analyzed how different molecules in the atmosphere react to particular wavelengths of light, using Hubble’s capabilities for spectroscopy. Water vapor in the planet’s atmosphere, for example, behaves in predictable ways in response to certain wavelengths of light, depending on the temperature of the water.

    Starlight is able to penetrate deep into a planet’s atmosphere, where it raises the temperature of the gas there. This gas then radiates its heat into space as infrared light. However, if there is cooler water vapor at the top of the atmosphere, the water molecules will prevent certain wavelengths of this light from escaping to space. But if the water molecules at the top of the atmosphere have a higher temperature, they will glow at the same wavelengths.

    “The emission of light from water means the temperature is increasing with height,” said Tiffany Kataria, study co-author based at NASA’s Jet Propulsion Laboratory, Pasadena, California. “We’re excited to explore at what longitudes this behavior persists with upcoming Hubble observations.”

    The phenomenon is similar to what happens with fireworks, which get their colors from chemicals emitting light. When metallic substances are heated and vaporized, their electrons move into higher energy states. Depending on the material, these electrons will emit light at specific wavelengths as they lose energy: sodium produces orange-yellow and strontium produces red in this process, for example. The water molecules in the atmosphere of WASP-121b similarly give off radiation as they lose energy, but in the form of infrared light, which the human eye is unable to detect.

    In Earth’s stratosphere, ozone gas traps ultraviolet radiation from the sun, which raises the temperature of this layer of atmosphere. Other solar system bodies have stratospheres, too; methane is responsible for heating in the stratospheres of Jupiter and Saturn’s moon Titan, for example.

    In solar system planets, the change in temperature within a stratosphere is typically around 100 degrees Fahrenheit (about 56 degrees Celsius). On WASP-121b, the temperature in the stratosphere rises by 1,000 degrees (560 degrees Celsius). Scientists do not yet know what chemicals are causing the temperature increase in WASP-121b’s atmosphere. Vanadium oxide and titanium oxide are candidates, as they are commonly seen in brown dwarfs, “failed stars” that have some commonalities with exoplanets. Such compounds are expected to be present only on the hottest of hot Jupiters, as high temperatures are needed to keep them in a gaseous state.

    “This super-hot exoplanet is going to be a benchmark for our atmospheric models, and it will be a great observational target moving into the Webb era,” said Hannah Wakeford, study co-author who worked on this research while at NASA’s Goddard Space Flight Center, Greenbelt, Maryland.

    See the full article here .

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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 11:49 am on July 7, 2017 Permalink | Reply
    Tags: , , , Hot Jupiters,   

    From Yale: “A cosmic barbecue: Researchers spot 60 new ‘hot Jupiter’ candidates” 

    Yale University bloc

    Yale University

    July 6, 2017

    Jim Shelton
    james.shelton@yale.edu
    203-361-8332

    1

    Yale researchers have identified 60 potential new “hot Jupiters” — highly irradiated worlds that glow like coals on a barbecue grill and are found orbiting only 1% of Sun-like stars.

    Hot Jupiters constitute a class of gas giant planets located so close to their parent stars that they take less than a week to complete an orbit.

    Second-year Ph.D. student Sarah Millholland and astronomy professor Greg Laughlin identified the planet candidates via a novel application of big data techniques. They used a supervised machine learning algorithm — a sophisticated program that can be trained to recognize patterns in data and make predictions — to detect the tiny amplitude variations in observed light that result as an orbiting planet reflects rays of light from its host star.

    Millholland recently presented the research at a Kepler Science Conference at the NASA Ames Research Center in California. She and Laughlin are authors of a study about the research, which has been accepted for publication in the Astronomical Journal.

    The Yale technique pioneers a new discovery method that identifies more planets from the publicly available Kepler data, said the researchers.

    The Doppler velocity method is a well-established technique that enables the detection of wobbling motion in a star due to the gravitational influence of an orbiting planet. Since hot Jupiters are so massive and close to their stars, the stellar wobbles they induce are large and readily detectable.

    A new, Yale-designed instrument known as EXPRES, which is being installed on the Discovery Channel Telescope in Arizona, may attempt to make confirmations later this year.

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    NSF funded Extreme Precision Spectrograph, EXPRES. The spectrograph will be commissioned at the Discovery Channel Telescope, part of the Lowell Observatory, near Flagstaff, Arizona

    Discovery Channel Telescope at Lowell Observatory, Happy Jack AZ, USA

    See the full article here .

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    Yale University Campus

    Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools. In addition, Yale encompasses a wide array of centers and programs, libraries, museums, and administrative support offices. Approximately 11,250 students attend Yale.

     
  • richardmitnick 7:00 am on June 15, 2017 Permalink | Reply
    Tags: , , , , Clouds over the sunlit arch, , Hot Jupiters, WASP-12 b   

    From astrobites: “Clouds over the sunlit arch” 

    Astrobites bloc

    Astrobites

    Jun 15, 2017
    Eckhart Spalding

    Title: High-temperature condensate clouds in super-hot Jupiter atmospheres
    Authors: H.R. Wakeford, C. Visscher, N.K. Lewis, T. Kataria, M.S. Marley, J.J. Fortney, A.M. Mandell
    First Author’s Institution: Planetary Systems Lab, NASA Goddard Space Flight Center

    Status: Published in MNRAS [open access]

    Introduction

    Having grown up on Earth, we tend to associate cloudy skies with brisk weather. Even gloomy weather. As Robert Frost said, if it’s the month of May and a “cloud comes over the sunlit arch” you’ll find yourself “two months back in the middle of March”. How different are clouds on alien worlds? Is there such a thing as searingly hot clouds, suspended high above in skies so bright they make your eyes ache when you shut them tight?

    If we want to study alien clouds outside our own solar system, “hot Jupiter” planets are our best test subjects. Hot Jupiters are gas giant planets which orbit very close to their host stars. Their atmospheres are relatively easy to characterize if they pass directly in front of their host star [transit], which allows light from the host star to pass through their extended atmospheres and provide us with transmission spectra.

    Planet transit. NASA/Ames

    In this light (no pun intended), the physics of clouds have experienced a recent surge of interest in the exoplanet field. Clouds play critical roles in an atmosphere’s energy balance: they can reflect light back into space, trap heat, remove absorbing compounds, influence wind structure and chemical reaction times, and exert feedback effects on atmospheric temperature-pressure profiles. Clouds also complicate measurements of chemical abundances, because clouds tend to dampen absorption features and can transmit photons as an unknown function of wavelength. (Remember when you got sunburned on a cloudy day?)

    Clouds in exoplanet atmospheres are a little bit like turbulence or magnetic fields in star formation– they add a rich level of physics to what would otherwise be a much simpler physical picture. But the first strong evidence of thick cloud decks on exoplanets dates only from 2014, and we still don’t know much about the nature of those clouds. (In fact we’re still working on Earth clouds. Earth is, after all, a little-known planet.)

    Today’s paper

    The authors of today’s paper push the boundaries of knowledge into the most scalding area of parameter space: the realm of sizzling “super-hot” Jupiters, with temperatures of more than 1800 K. Part of the authors’ motivation is to address a longstanding puzzle. The temperature in most planetary atmospheres should become colder at higher altitudes. But according to models, hot Jupiters with very high incident flux levels are expected to harbor high-altitude atmospheric absorbers like TiO or VO. If these compounds are present, they will cause a “temperature inversion” where temperature actually rises with altitude. Strangely, however, these compounds or temperature inversions have been difficult to find in hot Jupiters.

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    Fig. 1: The transmission spectrum of WASP-12 b. The y-axis represents the effective “thickness” of the atmosphere at a certain wavelength. Actual data are in the form of black data points, and pure condensate curves are in orange and green. The relative flatness on the left side of the plot indicates the presence of clouds. Before the James Webb Space Telescope (JWST) fills in the right side of this plot, the condensate models cannot be well distinguished. (Fig. 5 from today’s paper.)

    NASA/ESA/CSA Webb Telescope annotated

    The authors begin by considering the hottest condensates that may exist in a hot Jupiter atmosphere: calcium (Ca), titanium (Ti), and aluminum (Al). They assume cloud formation occurs when rising air reaches vapor pressure saturation, and that clouds stop forming when one of the constituent elements is depleted. They calculate the resulting relative cloud masses, play around with the atmospheric metallicities, and overlay temperature-pressure curves on condensation curves to see what types of clouds should form. Among their findings, Al compounds will form much more cloud material than Ti, and higher atmospheric metallicity levels allow the formation of more massive clouds.

    The authors turn to the specific case of the planet WASP-12 b. The transmission spectrum of WASP-12 b exhibits some water absorption but is otherwise fairly flat, which indicates the presence of clouds.

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    Fig. 2: Left: Solid colored lines represent temperature-pressure curves in different regions of WASP-12 b.

    4
    Hubble Finds a Star Eating a Planet. Artist’s concept of the exoplanet WASP-12b. Credit: NASA/ESA/G. Bacon

    NASA/ESA Hubble Telescope

    Dashed lines represent condensation curves for different compounds. Clouds will form between the temperature-pressure and condensation curves. For example, iron (Fe) clouds will exist on the night side at altitudes corresponding to pressures in bars (P) below log(P) = -1.5. Pressures accessible to transmission spectroscopy are between about log(P) of -1 to -4. (Note that pressure decreases as the y-axis increases.) Right: An alternative representation showing the effect of distance from the substellar point. Clouds will form on the nightside side of the lines. Vertical dashed lines show the regions between day and night sides probed by transmission spectroscopy. (Fig. 4 from today’s paper.)

    After doing some more model calculations, the authors overlay condensation curves on a 2D plot of temperature as a function of pressure and longitude. Interestingly, the clouds roasting in WASP-12 b’s atmosphere start to form right around the regions accessible to transit spectroscopy. At temperatures of less than 1900 K, WASP-12 b’s clouds can shroud the signatures of TiO or “hide” its constituents via condensation.

    There still is much work to be done in understanding clouds among the worlds that “favor fire“. Condensation nuclei and condensate growth are very poorly constrained, and more lab work is needed to determine the optics of different compounds. But there is light on the horizon (again no pun intended). Certain absorption bands including Ti-O vibrations are within the discovery space of JWST, which may allow us to distinguish between WASP 12 b clouds which hide TiO or remove Ti from the gas phase.

    That would bring us full circle: after predicting the compositions of clouds on super-hot Jupiters, today’s paper has left us with a test observation to disentangle the effect of clouds on WASP-12 b. That test will get us another step towards resolving the mystery of the missing thermal inversions.

    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 6:01 pm on June 5, 2017 Permalink | Reply
    Tags: , , , , , HAT-P-38 b, Hot Jupiters, , WASP-67 b   

    From Hubble: “Hubble’s Tale of Two Exoplanets: Nature vs. Nurture” 

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    Release type: American Astronomical Society Meeting

    Atmospheres of Two Hot Jupiters: Cloudy and Clear

    Astronomers once thought that the family of planets that orbit our sun were typical of what would eventually be found around other stars: a grouping of small rocky planets like Earth huddled close to their parent star, and an outer family of monstrous gaseous planets like Jupiter and Saturn.

    But ever since the discovery of the first planet around another star (or exoplanet) the universe looks a bit more complicated — if not downright capricious. There is an entire class of exoplanets called “hot Jupiters.” They formed like Jupiter did, in the frigid outer reaches of their planetary system, but then changed Zip code! They migrated inward to be so close to their star that temperatures are well over 1,000 degrees Fahrenheit.

    Astronomers would like to understand the weather on these hot Jupiters and must tease out atmospheric conditions by analyzing how starlight filters through a planet’s atmosphere. If the spectral fingerprint of water can be found, then astronomers conclude the planet must have relatively clear skies that lets them see deep into the atmosphere. If the spectrum doesn’t have any such telltale fingerprints, then the planet is bland-looking with a high cloud deck.

    Knowing the atmospheres on these distant worlds yields clues to how they formed and evolved around their parent star. In a unique experiment, astronomers aimed the Hubble Space Telescope at two “cousin” hot Jupiters that are similar in several respects. However, the researchers were surprised to learn that one planet is very cloudy, and the other has clear skies.

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    Ann Jenkins
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4488
    jenkins@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Giovanni Bruno
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-6823
    gbruno@stsci.edu

    2

    Is it a case of nature versus nurture when it comes to two “cousin” exoplanets? In a unique experiment, scientists used NASA’s Hubble Space Telescope to study two “hot Jupiter” exoplanets. Because these planets are virtually the same size and temperature, and orbit around nearly identical stars at the same distance, the team hypothesized that their atmospheres should be alike. What they found surprised them.

    Lead researcher Giovanni Bruno of the Space Telescope Science Institute in Baltimore, Maryland, explained, “What we’re seeing in looking at the two atmospheres is that they’re not the same. One planet—WASP-67 b—is cloudier than the other—HAT-P-38 b. We don’t see what we’re expecting, and we need to understand why we find this difference.”

    The team used Hubble’s Wide Field Camera 3 to look at the planets’ spectral fingerprints, which measure chemical composition.

    NASA/ESA Hubble WFC3

    “The effect that clouds have on the spectral signature of water allows us to measure the amount of clouds in the atmosphere,” Bruno said. “More clouds mean that the water feature is reduced.” The teams found that for WASP-67 b there are more clouds at the altitudes probed by these measurements.

    “This tells us that there had to be something in their past that is changing the way these planets look,” said Bruno.

    Today the planets whirl around their yellow dwarf stars once every 4.5 Earth days, tightly orbiting their stars closer than Mercury orbits our sun. But in the past, the planets probably migrated inward toward the star from the locations where they formed.

    Perhaps one planet formed differently than the other, under a different set of circumstances. “You can say it’s nature versus nurture,” explains co-investigator Kevin Stevenson. “Right now, they appear to have the same physical properties. So, if their measured composition is defined by their current state, then it should be the same for both planets. But that’s not the case. Instead, it looks like their formation histories could be playing an important role.”

    The clouds on these hot, Jupiter-like gas giants are nothing like those on Earth. Instead, they are probably alkali clouds, composed of molecules such as sodium sulfide and potassium chloride. The average temperature on each planet is more than 1,300 degrees Fahrenheit.

    The exoplanets are tidally locked, with the same side always facing the parent star. This means they have a very hot day-side and a cooler night-side. Instead of sporting multiple cloud bands like Jupiter does, each probably has just one broad equatorial band that slowly moves the heat around from the day-side to the night-side.

    The team is just beginning to learn what factors are important in making some exoplanets cloudy and some clear. To better understand what the planets’ pasts may have been, scientists will need future observations with Hubble and the soon-to-be-launched James Webb Space Telescope.

    The team’s results were presented on June 5 at the 230th meeting of the American Astronomical Society in Austin, Texas.

    The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.
    Credits

    Illustration: NASA, ESA, and Z. Levy (STScI)
    Science: NASA, ESA, and G. Bruno (STScI)

    See the full article here .

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  • richardmitnick 12:36 pm on April 18, 2017 Permalink | Reply
    Tags: , , Hot Jupiters   

    From AAS NOVA: “Samples and Statistics: Distinguishing Populations of Hot Jupiters in a Growing Dataset” 

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    American Astronomical Society

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    18 April 2017
    Jamila Pegues

    Title: Evidence for Two Hot Jupiter Formation Paths
    Authors: Benjamin E. Nelson, Eric B. Ford, and Frederic A. Rasio
    First Author’s Institution: Northwestern University

    Status: Submitted to AJ, open access

    5
    Figure 1: A gorgeous artist’s impression of a hot Jupiter orbiting around its host star. [ESO/L. Calçada]

    Frolicking Through Fields of Data

    The future of astronomy observations seems as bright as the night sky … and just as crowded! Over the next decade, several truly powerful telescopes are set to launch (read about a good number of them here and also here).

    1
    NASA/TESS

    Giant Magellan Telescope, Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile

    TMT-Thirty Meter Telescope, proposed for Mauna Kea, Hawaii, USA

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile


    LSST Camera, built at SLAC



    LSST telescope, currently under construction at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    NASA/ESA/CSA Webb Telescope annotated

    NASA/WFIRST

    FAST radio telescope, now operating, located in the Dawodang depression in Pingtang county Guizhou Province, South China

    That means we’re going to have a LOT of data on everything from black holes to galaxies, and beyond — and that’s in addition to the huge fields of data from the past decade that we’re already frolicking through now. It’s certainly far more data than any one astronomer (or even a group of astronomers) wants to analyze one-by-one; that’s why these days, astronomers turn more and more to the power of astrostatistics to characterize their data.

    The authors of today’s astrobite had that goal in mind. They explored a widely-applicable, data-driven statistical method for distinguishing different populations in a sample of data. In a sentence, they took a large sample of hot Jupiters and used this technique to try and separate out different populations of hot Jupiters — based on how the planets were formed — within their sample. Let’s break down exactly what they did, and how they did it, in the next few sections!

    Hot Jupiters Are Pretty Cool

    First question: what’s a hot Jupiter, anyway?

    They’re actually surprisingly well-named: essentially, they are gas-giant planets like Jupiter, but are much, much hotter. (Read all about them in previous astrobites, like this one and this other one!) Hot Jupiters orbit perilously close to their host stars — closer even than Mercury does in our own Solar System, for example. But it seems they don’t start out there. It’s more likely that these hot Jupiters formed out at several AU from their host stars, and then migrated inward into the much closer orbits from there.

    As to why hot Jupiters migrate inward … well, it’s still unclear. Today’s authors focused on two migration pathways that could lead to two distinct populations of hot Jupiters in their sample. These migration theories, as well as what the minimum allowed distance to the host star (the famous Roche separation distance, aRoche) would be in each case, are as follows:

    Disk migration: hot Jupiters interact with their surrounding protoplanetary disk, and these interactions push their orbits inward. In this context, aRoche corresponds to the minimum distance that a hot Jupiter could orbit before its host star either (1) stripped away all of the planet’s gas or (2) ripped the planet apart.
    Eccentric migration: hot Jupiters start out on very eccentric (as in, more elliptical than circular) orbits, and eventually their orbits morph into circular orbits of distance 2aRoche. In this context, aRoche refers to the minimum distance that a hot Jupiter could orbit before the host star pulled away too much mass from the planet.

    The authors defined a parameter ‘x’ for a given hot Jupiter to be x = a/aRoche, where ‘a’ is the planet’s observed semi-major axis. Based on the minimum distances in the above theories, we could predict that hot Jupiters that underwent disk migration would have a minimum x-value of x = aRoche/aRoche = 1. On the other hand, hot Jupiters that underwent eccentric migration would instead have a minimum x-value of x = 2aRoche/aRoche = 2. This x for a given planet is proportional to the planet’s orbital period ‘P’, its radius ‘R’, and its mass ‘M’ in the following way:

    And this x served as a key parameter in the authors’ statistical models!

    Toying with Bayesian Statistics

    Next question: how did today’s authors statistically model their data?

    4
    Figure 2: Probability distribution of x for each observation group, assuming that each hot Jupiter orbit was observed along the edge (like looking at the thin edge of a DVD). The bottom panel zooms in on the top one. Note how the samples have different minimum values! [Nelson et al. 2017]

    Short answer: with Bayesian statistics. Basically, the authors modeled how the parameter x is distributed within their planet sample with truncated power laws — so, x raised to some power, cut off between minimum and maximum x values. They split their sample of planets into two groups, based on the telescope and technique used to observe the planets: “RV+Kepler” and “HAT+WASP”. Figure 2 displays the distribution of x for each of the subgroups.

    The authors then used the Markov Chain Monte Carlo method (aka, MCMC; see the Bayesian statistics link above) to explore what sort of values of the power laws’ powers and cutoffs would well represent their data. Based on their chosen model form, they found that the RV+Kepler sample fit well with their model relating to eccentric migration. On the other hand, they found evidence that the HAT+WASP sample could be split into two populations: about 15% of those planets corresponded to disk migration, while the other 85% or so corresponded to eccentric migration.

    Remember that a major goal of today’s authors was to see if they could use this statistical approach to distinguish between planet populations in their sample … and in that endeavor, they were successful! The authors were thus optimistic about using this statistical technique for a much larger sample of hot Jupiters in the future, as oodles of data stream in from telescopes and surveys like KELT, TESS, and WFIRST over the next couple of decades.

    Their success joins the swelling toolbox of astrostatistics … and just in time! Telescopes of the present and very-near future are going to flood our computers with data — so unless we’re willing to examine every bright spot we observe in the sky by hand, we’ll need all the help from statistics that we can get!

    See the full article here .

    Please help promote STEM in your local schools.

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  • richardmitnick 9:30 am on April 5, 2017 Permalink | Reply
    Tags: , , , , , Hot Jupiters   

    From astrobites: “Samples and Statistics: Distinguishing Populations of Hot Jupiters in a Growing Dataset” 

    Astrobites bloc

    Astrobites

    Apr 5, 2017
    Jamila Pegues

    Title: Evidence for Two Hot Jupiter Formation Paths
    Authors: Benjamin E. Nelson, Eric B. Ford, and Frederic A. Rasio
    First Author’s Institution: Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, IL, USA; Northwestern Institute for Complex Systems, IL, USA

    Status: Submitted to AJ, open access

    Frolicking through fields of data

    The future of astronomy observations seems as bright as the night sky… and just as crowded! Over the next decade, several truly powerful telescopes are set to launch (read about a good number of them here and also here). That means we’re going to have a LOT of data on everything from black holes to galaxies, and beyond – and that’s in addition to the huge fields of data from the past decade that we’re already frolicking through now. It’s certainly far more data than any one astronomer (or even a group of astronomers) wants to analyze one-by-one – that’s why these days, astronomers turn more and more to the power of astrostatistics to characterize their data.

    The author’s of today’s astrobite had that goal in mind. They explored a widely-applicable, data-driven statistical method for distinguishing different populations in a sample of data. In a sentence, they took a large sample of hot Jupiters and used this technique to try and separate out different populations of hot Jupiters, based on how the planets were formed, within their sample. Let’s break down exactly what they did, and how they did it, in the next few sections!

    Hot Jupiters are pretty cool

    First question: what’s a hot Jupiter, anyway?

    They’re actually surprisingly well-named: essentially, they are gas giant planets like Jupiter, but are much, much hotter. (Read all about them in previous astrobites, like this one and this other one!) Hot Jupiters orbit perilously close to their host stars – closer even than Mercury does in our own Solar System, for example. But it seems they don’t start out there. It’s more likely that these hot Jupiters formed out at several AU from their host stars, and then migrated inward into the much closer orbits from there.

    2
    Figure 1: A gorgeous artist’s impression of a hot Jupiter orbiting around its host star. Image credit goes to ESO/L. Calçada.

    As to why hot Jupiters migrate inward… well, it’s still unclear. Today’s authors focused on two migration pathways that could lead to two distinct populations of hot Jupiters in their sample. These migration theories, as well as what the minimum allowed distance to the host star (the famous Roche separation distance, aRoche) would be in each case, are as follows:

    Disk migration: hot Jupiters interact with their surrounding protoplanetary disk, and these interactions push their orbits inward. In this context, aRoche corresponds to the minimum distance that a hot Jupiter could orbit before its host star either (1) stripped away all of the planet’s gas or (2) ripped the planet apart.
    Eccentric migration: hot Jupiters start out on very eccentric (as in, more elliptical than circular) orbits, and eventually their orbits morph into circular orbits of distance 2aRoche. In this context, aRoche refers to the minimum distance that a hot Jupiter could orbit before the host star pulled away too much mass from the planet.

    The authors defined a parameter ‘x’ for a given hot Jupiter to be x = a/aRoche, where ‘a’ is the planet’s observed semi-major axis. Based on the minimum distances in the above theories, we could predict that hot Jupiters that underwent disk migration would have a minimum x value of x = aRoche/aRoche = 1. On the other hand, hot Jupiters that underwent eccentric migration would instead have a minimum x value of x = 2aRoche/aRoche = 2. This x for a given planet is proportional to the planet’s orbital period ‘P’, its radius ‘R’, and its mass ‘M’ in the following way:

    And this x served as a key parameter in the authors’ statistical models!

    Toying with Bayesian statistics

    Next question: how did today’s authors statistically model their data?

    4
    Figure 2: Probability distribution of x for each observation group, assuming that each hot Jupiter orbit was observed along the edge (like looking at the thin edge of a DVD). The bottom panel zooms in on the top one. Note how the samples have different minimum values! From Figure 1 in the paper.

    Short answer: with Bayesian statistics. Basically, the authors modeled how the parameter x is distributed within their planet sample with truncated power laws – so, x raised to some power, cutoff between minimum and maximum x values. They split their sample of planets into two groups, based on the telescope and technique used to observe the planets: “RV+Kepler” and “HAT+WASP”. Figure 2 displays the distribution of x for each of the subgroups.

    The authors then used the Markov Chain Monte Carlo method (aka, MCMC; see the Bayesian statistics link above!) to explore what sort of values of the power laws’ powers and cutoffs would well represent their data. Based on their chosen model form, they found that the RV+Kepler sample fit well with their model relating to eccentric migration. On the other hand, they found evidence that the HAT+WASP sample could be split into two populations: about 15% of those planets corresponded to disk migration, while the other 85% or so corresponded to eccentric migration.

    Remember that a major goal of today’s authors was to see if they could use this statistical approach to distinguish between planet populations in their sample… and in that endeavor, they were successful! The authors were thus optimistic about using this statistical technique for a much larger sample of hot Jupiters in the future, as oodles of data stream in from telescopes and surveys like KELT [North], TESS, and WFIRST over the next couple of decades.

    NASA/TESS

    NASA/WFIRST

    Their success joins the swelling toolbox of astrostatistics… and just in time! Telescopes of the present and very-near future are going to flood our computers with data – so unless we’re willing to examine every bright spot we observe in the sky by hand, we’ll need all the help from statistics that we can get!

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    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 1:38 pm on January 20, 2017 Permalink | Reply
    Tags: , , , , , , HATnet, Hot Jupiters   

    From AAS NOVA: “Reinflating Giant Planets” 

    AASNOVA

    American Astronomical Society

    18 January 2017
    Susanna Kohler

    1
    Artist’s impression of a hot Jupiter exoplanet transiting across the face of its host star. [NASA/ESA/C. Carreau]

    Two new, large gas-giant exoplanets have been discovered orbiting close to their host stars. A recent study examining these planets — and others like them — may help us to better understand what happens to close-in hot Jupiters as their host stars reach the end of their main-sequence lives.

    2
    Unbinned transit light curves for HAT-P-65b. [Adapted from Hartman et al. 2016]

    Oversized Giants

    The discovery of HAT-P-65b and HAT-P-66b, two new transiting hot Jupiters, is intriguing. These planets have periods of just under 3 days and masses of roughly 0.5 and 0.8 times that of Jupiter, but their sizes are what’s really interesting: they have inflated radii of 1.89 and 1.59 times that of Jupiter.

    These two planets, discovered using the Hungarian-made Automated Telescope Network (HATNet) in Arizona and Hawaii, mark the latest in an ever-growing sample of gas-giant exoplanets with radii larger than expected based on theoretical planetary structure models.

    HATNet telescopes at Fred Lawrence Whipple Observatory, Mount Hopkins, Arizona. Photo credit: Gaspar Bakos.pple-observatory-mount-hopkins-arizona-photo-credit-gaspar-bakos
    HATNet telescopes at Fred Lawrence Whipple Observatory, Mount Hopkins, Arizona. Photo credit: Gaspar Bakos

    HATnet, Mauna Kea Hawaii USA
    HATNet, Mauna Kea Hawaii USA

    What causes this discrepancy? Did the planets just fail to contract to the expected size when they were initially formed, or were they reinflated later in their lifetimes? If the latter, how? These are questions that scientists are only now starting to be able to address using statistics of the sample of close-in, transiting planets.

    Exploring Other Planets

    4
    Unbinned transit light curves for HAT-P-66b. [Hartman et al. 2016]

    Led by Joel Hartman (Princeton University), the team that discovered HAT-P-65b and HAT-P-66b has examined these planets’ observed parameters and those of dozens of other known close-in, transiting exoplanets discovered with a variety of transiting exoplanet missions: HAT, WASP, Kepler, TrES, and KELT. Hartman and collaborators used this sample to draw conclusions about what causes some of these planets to have such large radii.

    The team found that there is a statistically significant correlation between the radii of close-in giant planets and the fractional ages of their host stars (i.e., the star’s age divided by its full expected lifetime). The two newly discovered hot Jupiters with inflated radii, for instance, are orbiting stars that are roughly 84% and 83% through their life spans and are approaching the main-sequence turnoff point.

    6
    Fractional age of the host stars of close-in transiting exoplanets vs. the planet’s radius. There is a statistically significant correlation between age and planet radius. [Adapted from Hartman et al. 2016]

    Late-Life Reinflation

    Hartman and collaborators propose that the data support the following scenario: as host stars evolve and become more luminous toward the ends of their main-sequence lifetimes, they deposit more energy deep into the interiors of the planets closely orbiting them. These close-in planets then increase their equilibrium temperatures — and their radii reinflate as a result.

    Based on these results, we would expect to continue to find hot Jupiters with inflated radii primarily orbiting closely around older stars. Conversely, close-in giant planets around younger stars should primarily have non-inflated radii. As we continue to build our observational sample of transiting hot Jupiters in the future, we will be able to see how this model holds up.

    Citation

    J. D. Hartman et al 2016 AJ 152 182. doi:10.3847/0004-6256/152/6/182

    See the full article here .

    Please help promote STEM in your local schools.

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  • richardmitnick 12:26 pm on June 22, 2016 Permalink | Reply
    Tags: , , , , Hot Jupiters, Where the Wild (Planet)Things Are   

    From Astrobites: Where the Wild (Planet)Things Are 

    New research shows hot Jupiters find safety in numbers. According to radial velocity data, these giant exoplanets are more commonly found around stars in open clusters.

    Source: Where the Wild (Planet)Things Are

    Title: Search for giant planets in M67 III: excess of hot Jupiters in dense open clusters
    Authors: A. Brucalassi, L. Pasquini, R. Saglia, M.T. Ruiz, P. Bonifacio, I. Leão, B.L. Canto Martins, J.R. de Medeiros, L. R. Bedin, K. Biazzo, C. Melo, C. Lovis, and S. Randich

    First Author’s Institution: Max-Planck für extraterrestrische Physik, Garching bei München, Germany

    Status: Accepted for publication in A&A Journal Letters

    If you wanted to discover a new giant exoplanet, where would you look? New research, shows that star clusters are a good place to start, at least if you want to look for giant exoplanets close to their host star.

    Hot Jupiters are a breed of exoplanets that have masses about or larger than Jupiter and orbit a star in 10 days or less (for comparison, Mercury takes 88 days to go around the Sun). When they were first discovered, they posed a problem to planet formation models as it was thought gas giants could only form far from their host star where it was cool enough for ices to form, which allows for larger planets to be made. Since then, studies have shown these planets could form far out and migrate inwards over their lifetime. This can happen through interactions with the disk in which the planet forms (known as Type II migration), or through gravitational scattering with other planets or nearby stars.

    Brucalassi and her team decided to investigate an open cluster in the Milky Way (Messier 67) to look for hot Jupiters. Over several years they used three different telescopes (the ESO 3.6m telescope, the Hobby Eberly Telescope and the TNG on La Palma of the Canary Islands) to take high-precision spectra of 88 stars, 12 of which are binary stars. This spectra could then be analyzed for small blue- and redshifts which indicate the star is moving slightly. In this case, that movement is caused by the presence of another body, the exoplanet. This method is known as the radial velocity method and is the method that was used in the first exoplanet discoveries. To make sure that each star’s own activity wasn’t affecting its spectra, the group measured the Hα line which shows how active the star’s chromosphere is. Figure 1 shows an example of the radial velocity measurements.

    1
    Figure 1: Radial velocity measurements for YBP401. The coloured dots represent the different telescopes the measurements were made at. The measurements show an exoplanet with a period of just 4.08 days.

    The group’s measurements revealed a new exoplanet around the main sequence star YBP401. They were also able to get better measurements on two stars (YBP1194 and YBP1514) with known hot Jupiters. This brought the total number of hot Jupiters to 3 out of 88 stars. Although 3 might not seem like a very big number, it is larger than the number of hot Jupiters found around field stars (stars not in clusters). For the statistical analysis, Brucalassi compares the number of exoplanets with the number of main sequence and subgiant stars, i.e. stars that are not yet at the ends of their lives. Of the 88 stars, 66 are main sequence or subgiant, and of those only 53 are not binary stars. Most radial velocity studies choose to not observe binary stars so it is important to compare numbers with that in mind. A previous study from 2012 found a hot Jupiter frequency of 1.2% ± 0.38 around field stars. Brucalassi finds 4.5+4.5-2.5% when comparing with only single stars (not including binaries) in M67. To compare with statistics from the Kepler mission, binaries are included, as Kelper also surveys binaries, and the percentage for hot Jupiters in a cluster is 5.6+5.4-2.6%. The Kepler mission finds a frequency of hot Jupiters of just ~0.4%, which is considerably lower. And this trend isn’t seen just in M67. Combining radial velocity surveys for the clusters M67, Hyades, and Praesepe, there are 6 hot Jupiters in 240 surveyed stars, whereas the study from 2012 found only 12 in survey of 836 field stars.

    It’s known that systems with more metals tend to produce more planets and the star’s mass may also have an effect on planet production. However, the clusters stars and field stars are on average the same mass, so this alone cannot account for the differneces. M67 is also at solar metallicity (i.e. it’s stars tend to have the same amount of metals as our Sun) so this can also not account for the excess of hot Jupiters. Brucalassi concludes that the high number of hot Jupiters is due to the environment. Past simulations show that stars in a crowded cluster environment will experience at least one close encounter with another star, which is all that is needed to drive a Jupiter in to a closer orbit. This new research gives further evidence to this theory, putting us one step closer to understanding how exoplanets can form.

    3
    Figure 2: An artist’s rendition of the new hot Jupiter. Click on the image for a full animated video of the M67 cluster. Courtesy of the ESO press release (#eso1621).

     
  • richardmitnick 4:49 pm on March 31, 2016 Permalink | Reply
    Tags: , , , Hot Jupiters, TYC 3667-1280-1   

    From astrobites: “A Warm Jupiter around an Evolving Star: Exploring Planet Migration” 

    Astrobites bloc

    Astrobites

    Mar 31, 2016
    Matthew Green

    Title: TAPAS IV. TYC 3667-1280-1 b – the most massive red giant star hosting a warm Jupiter
    Authors: A. Niedzielski, E. Villaver, G. Nowak, M. Adamów, G. Maciejewski, K. Kowalik, A. Wolszczan, B. Deka-Szymankiewicz, M. Adamczyk
    First Author’s Institution: Toruń Centre for Astronomy, Nicolaus Copernicus University, Toruń, Poland
    Status: Accepted by A&A

    Planetary systems are dynamic places. Some planetary orbits change over time, moving the planet either closer in towards the star or further out. Not only that, but the stars in the centre of planetary systems will eventually evolve off the main sequence, growing into giants and then, in most cases, collapsing into white dwarfs. This can significantly change the planetary system as a whole, in some cases leading to planets being swallowed by their host stars or ejected from the system. Of course, these changes occur over timescales of millions to billions of years.

    There has recently been a spike of interest in what happens to planets as their host star evolves, inspired by the discovery of a system of disintegrating planets around a white dwarf. Today’s paper introduces TYC 3667-1280-1, a Jupiter-mass exoplanet whose host star is in the process of evolving into a giant. The authors believe that the planet is of interest not only because of its evolving host, but also because of the planet’s potentially revealing migration history.

    Stars as Homes for Habitable Planetary Systems. JPL-Caltech
    Stars as Homes for Habitable Planetary Systems. JPL-Caltech

    Warm Jupiters and the Kozai-Lidov mechanism

    Planets of Jupiter mass, like TYC 3667-1280-1, are thought to form far out in the system, where there is more material from which they can form. However, we have seen many Jupiter-mass planets which are incredibly close to their host star, often much closer than the Earth is to the Sun. Consequentially these systems have very short orbital periods. The so-called hot Jupiters have orbits shorter than 10 days, while “warm Jupiters” have orbits of 10-100 days (compare this to Jupiter’s orbital period of 12 years).

    How did these planets end up so close to their host stars? Warm and hot Jupiters may have travelled inwards by different means. Jupiter-mass planets can migrate inwards by being gravitationally pushed to high eccentricities (highly elliptical orbits). However, many systems in both classes have orbits with very low (their orbits are almost perfect circles). In hot Jupiters, the planet’s orbit can be “circularised” again by the gravitational pull of the star — however, this doesn’t work as well across the distances at which warm Jupiters orbit. How, then, do we explain the low eccentricities in some warm Jupiters?

    There’s also a second mystery around warm Jupiters. We see fewer hot and warm Jupiters around evolved or evolving stars than we do around main sequence stars. For hot Jupiters this is easily explained: for most of these systems, the planet is close enough to have been swallowed by its host star. However, warm Jupiters are further out from their stars, and so we would expect them to last longer than they seem to.

    Both of these problems might be explained by an effect known as the Kozai-Lidov mechanism. This is a tidal effect that occurs in hierarchical three-body systems – that is, systems in which two of the bodies (in this case, a star and a planet) are in a tight orbit around each other, with a third object in a wider orbit around the two (a potentially unseen companion such as a brown dwarf). If the orbit of the outer object is tilted relative to the orbits of the inner binary, the gravity of the outer object pulls on the inner pair in such a way that the eccentricity of their orbits fluctuates. (For more detail on the Kozai-Lidov mechanism, see Erika Nesvold’s section in this astrobite.) The low-eccentricity warm Jupiters that we see could simply be those in a low-eccentricity phase of these fluctuations.

    Conversely, when the planet fluctuates up to a highly eccentric orbit it will pass much closer to its host star, causing it to be swallowed by the expanding star much earlier than it would be if there were no Kozai-Lidov mechanism in play. In fact, for a sample system their simulations showed the planet might be swallowed by the time the star grew to 5 solar radii, compared to 40 solar radii for the same system with no Kozai-Lidov mechanism.

    TYC 3667-1280-1

    Enter TYC 3667-1280-1, whose star has a radius of 6.3 solar radii — putting it just inside the range of what should have been swallowed if the Kozai-Lidov mechanism is at work in this system. In other respects TYC 3667-1280-1 appears to be a typical warm Jupiter, having the low eccentricity (0.036 in this case) that could imply the Kozai-Lidov mechanism is at work. Further studies of TYC 3667-1280-1 could help clear up this seeming conflict, as well as helping us to understand the Kozai-Lidov mechanism further.

    The science team:
    A. Niedzielski1, E. Villaver2, G. Nowak3; 4; 1, M. Adamów5; 1, G. Maciejewski1, K. Kowalik6, A. Wolszczan7; 8, B.
    Deka-Szymankiewicz1, and M. Adamczyk1
    1 Toru´n Centre for Astronomy, Faculty of Physics, Astronomy and Applied Informatics, Nicolaus Copernicus University in Toru´n,
    Grudziadzka 5, 87-100 Toru´n, Poland. e-mail: Andrzej.Niedzielski@umk.pl
    2 Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco 28049 Madrid, Spain. e-mail:
    Eva.Villaver@uam.es
    3 Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife, Spain.
    4 Departamento de Astrofísica, Universidad de La Laguna, E-38206 La Laguna, Tenerife, Spain.
    5 McDonald Observatory and Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1402, Austin, Texas,
    78712-1206, USA.
    6 National Center for Supercomputing Applications, University of Illinois, Urbana-Champaign, 1205 W Clark St, MC-257, Urbana,
    IL 61801, USA
    7 Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802,
    USA. e-mail: alex@astro.psu.edu
    8 Center for Exoplanets and Habitable Worlds, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802,
    USA.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    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.

     
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