DOCSLIB.ORG

Spitzer Approved Warm Mission Abstracts

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Printed by SSC Jan 29, 20 19:21 Spitzer Approved Warm Mission Abstracts Page 1/750 Jan 29, 20 19:21 Spitzer Approved Warm Mission Abstracts Page 2/750 Spitzer Space Telescope − Directors Discretionary Time Proposal #13159 Spitzer Space Telescope − General Observer Proposal #60167 Variability at the edge: highly accreting objects in Taurus Disk tomography and dynamics: a time−dependent study of known mid−infrared Principal Investigator: Peter Abraham variable young stellar objects Institution: Konkoly Observatory Principal Investigator: Peter Abraham Technical Contact: Peter Abraham, Konkoly Observatory Institution: Konkoly Observatory of the Hungarian Academy of Science Co−Investigators: Technical Contact: Peter Abraham, Konkoly Observatory of the Hungarian Agnes Kospal, Konkoly Observatory Academy of Science Robert Szabo, Konkoly Observatory Co−Investigators: Science Category: YSOs Jose Acosta−Pulido, Instituto de Astrofisica de Canarias Observing Modes: IRAC Post−Cryo Mapping Cornelis P. Dullemond, Max−Planck−Institut fur Astronomie Hours Approved: 9.3 Carol A. Grady, Eureka Sci/NASA Goddard Thomas Henning, Max−Planck−Institut fur Astronomie Abstract: Attila Juhasz, Max−Planck−Institut fur Astronomie In Kepler K2, Campaign 13, we will obtain 80−days−long optical light curves of Csaba Kiss, Konkoly Observatory seven highly accreting T Tauri stars in the benchmark Taurus star forming Agnes Kospal, Leiden Observatory region. Here we propose to monitor our sample simultaneously with Kepler and Maria Kun, Konkoly Observatory Spitzer, to be able to separate variability patterns related to different David Westley Miller, University of Louisville physical processes. Monitoring our targets with Spitzer during the final 11 Attila Moor, Konkoly Observatory days of the K2 campaign, we will clean the light curves from non−accretion Aurora Sicilia−Aguilar, Max−Planck−Institut fur Astronomie effects (rotating stellar spots, dips due to passing dust structures), and construct, for the first time, a variability curve which reflects the Science Category: young stellar objects time−dependent accretion only. We will then study and understand how Observing Modes: IRAC Post−Cryo Mapping time−dependent mass accretion affects the density and temperature structure of Hours Approved: 49.3 the protoplanetary disk, which sets the initial conditions for planet formation. The proposed work cannot be done without the unparalleled precision Abstract: of Kepler and Spitzer. This unique and one−time opportunity motivated our DDT Most of our knowledge on young stars comes from snapshot observations: spectra proposal. and images taken at a single epoch, or at different epochs at different wavelengths. It is, however, known that many of the systems are variable. Variability at optical and near−infrared wavelength is mostly related to the central star itself. Mid−infrared flux changes, on the other hand, are in most cases due to varying emission of the circumstellar material, either via varying accretion rate (and thus changing thermal emission), or varying extinction along the line−of−sight (shadowing effects). If the illuminated disk area varies with time, measuring the variable integrated flux offers a tomographic analysis. Monitoring and interpreting variability provide a powerful "extra dimension" of information on the structure of the circumstellar material. The Spitzer Warm Mission is a unique opportunity for the systematic establishment of mid−infrared variability studies of young stars. Following an extensive preparatory work, we compiled a list of young stellar objects with variable mid−infrared brightness. We propose to conduct a multi−epoch survey of these carefully selected pre−main sequence stars with Spitzer. We plan to complement the Spitzer observations with simultaneous optical and near−infrared photometry from ground−based telescopes. Our aim is to document the mid−infrared brightness evolution of our targets, examine the possible reasons of the observed variability, model disk structure and dynamics for different scenarios and confront the data with model predictions. Wednesday January 29, 2020 Spitzer_abstracts_warm.txt 1/375 Printed by SSC Jan 29, 20 19:21 Spitzer Approved Warm Mission Abstracts Page 3/750 Jan 29, 20 19:21 Spitzer Approved Warm Mission Abstracts Page 4/750 Spitzer Space Telescope − General Observer Proposal #80165 Spitzer Space Telescope − Directors Discretionary Time Proposal #14223 Revisiting and refining the model of TRAPPIST−1 with Spitzer Disk tomography during the outburst of two new young eruptive stars Principal Investigator: Eric Agol Principal Investigator: Peter Abraham Institution: University of Washington Institution: Konkoly Observatory Technical Contact: Eric Agol, University of Washington Technical Contact: Peter Abraham, Konkoly Observatory Co−Investigators: Co−Investigators: Emeline Bolmont, University of Geneva Agnes Kospal, Leiden Observatory Adam Burgasser, UCSD Attila Moor, Konkoly Observatory Sean Carey, IPAC Laetitia Delrez, University of Cambridge Science Category: young stellar objects Brice−Olivier Demory, University of Bern Observing Modes: IRAC Post−Cryo Mapping Dan Fabrycky, University of Chicago Hours Approved: 1.8 Michael Gillon, University of Liege Simon Grimm, University of Bern Abstract: Jim Ingalls, IPAC Most young stars are variable, and not only at optical, but also at infrared Renu Malhotra, University of Arizona wavelengths. Our group had proposed a new method to interpret such light Brett Morris, University of Washington variations using a tomographic technique. It is based on analyzing the time Sean Raymond, University of Bordeaux variations of the integrated flux of a shrinking illuminated disk area during Amaury Triaud, University of Birmingham the fading. We also suggested that rearrangement in the density structure of the inner disk − mainly due to evaporation/condensation of dust particles in the Science Category: Exoplanets outburst heat − can be seen in the multicolor light curves. The outbursts of two Observing Modes: IRAC Post−Cryo Mapping so−far unknown young eruptive stars in Cygnus in 2010 August offer the Hours Approved: 103.0 long−waited opportunity to perform a proof−of−concept analysis of our proposed Priority: 1 methods to investigate disk tomography and dynamics. Here we propose to conduct a multi−epoch survey of two young eruptive star during their outburst with Spitzer/IRAC. We will obtain 3.6 and 4.5 um images at 9 epochs, and the data Abstract: will be supplemented by simultaneous ground−based optical and near−infrared With the Spitzer Space Telescope, we have discovered a system of seven photometry. The flux and color variations of HBC 722 will be interpreted using transiting planets about the star TRAPPIST−1, and for the first time measured the new method of disk tomography, while the corresponding data on VSX the densities of three Earth−sized, temperate exoplanets using transit−timing J205126.1+440523 will be interpreted in terms of the sum of variable variations (Gillon et al. 2017; Ducrot et al. 2018; Grimm et al. 2018). We illumination and time variable density structure of the inner disk/envelope. propose to gather additional transits of the TRAPPIST−1 system, focusing on the Our study may demonstrate that variability, in particular the wavelength outer planets in the system which have had fewer transits observed to date. The dependence of flux variations over the whole infrared domain, provides an four−fold goals of this proposal are: i). to flag potential transits which extremely powerful ?extra dimension? of information, in addition to space and might be affected by stellar variability; ii). to constrain the dynamical state wavelength. of the planet system; iii). to better constrain the masses of the planets; iv). to tighten the ephemeris forecast for observations with JWST. In addition, we will search for any evidence an eighth planet, characterize the stellar variability, and forecast planet−planet overlaps during transits. The proposed observations contain measurements which are only possible in March−April 2019, and so we request a time critical review to the extent possible. Wednesday January 29, 2020 Spitzer_abstracts_warm.txt 2/375 Printed by SSC Jan 29, 20 19:21 Spitzer Approved Warm Mission Abstracts Page 5/750 Jan 29, 20 19:21 Spitzer Approved Warm Mission Abstracts Page 6/750 Spitzer Space Telescope − General Observer Proposal #70157 Spitzer Space Telescope − General Observer Proposal #12112 Star formation in the 4th Galactic Quadrant Variability of Two Young L/T Transition Brown Dwarfs Principal Investigator: Lori Allen Principal Investigator: Katelyn Allers Institution: Smithsonian Astrophysical Observatory Institution: Institute for Astronomy Technical Contact: Lori Allen, Smithsonian Astrophysical Observatory Technical Contact: Katelyn Allers, Institute for Astronomy Co−Investigators: Co−Investigators: Sarah Willis, Iowa State University Beth Biller, University of Edinburgh Massimo Marengo, Iowa State University Jack Gallimore, Bucknell University Tom Megeath, University of Toledo Ian Crossfield, Lunar and Planetary Lab, University of Arizona Rob Gutermuth, University of Massachusetts / Smith College Science Category: brown dwarfs/very low mass stars Science Category: star formation Observing Modes: IRAC Post−Cryo Mapping Observing Modes: IRAC Post−Cryo Mapping Hours Approved: 29.7 Hours Approved: 35.5 Priority: 2 Abstract: Abstract: Empirical scaling laws relating star formation rates to gas surface density in We propose for
Recommended publications
  • Adaptive Optics Imaging of Circumstellar Environments

    Adaptive Optics Imaging of Circumstellar Environments

    Star Formation at High Angular Resolution IAU Symposium, Vol. 221, 2004 M. G. Burton, R. Jayawardhana & T.L. Bourke, eds. Adaptive Optics Imaging of Circumstellar Environments Daniel Apai, Ilaria Pascucci, Hongchi Wang, Wolfgang Brandner and Thomas Henning Max Planck Institute for Astronomy, Kimiqsiuhl 17., Heidelberg, Germany D-69117 Carol Grady NOAO/STIS, Goddard Space Flight Center, Code 681, NASA/GSFC, Greenbelt, MD 20771, USA Dan Potter Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721, USA Abstract. We present results from our high-resolution, high-contrast imaging campaign targeting the circumstellar environments of young, nearby stars of different masses. The observations have been conducted using the ALFA/CA 3.5m and NACO UT4/VLT adaptive optics systems. In order to enhance the contrast we applied the methods PSF-subtraction and polarimetric differential imaging (PDI). The observations of young stars yielded the identification of numerous new companion candidates, the most interesting one being rv 0.5" from FU Ori. We also obtained high-resolution near-infrared imaging of the circumstellar envelope of SU Aur and AB Aur. Our PDI of the TW Hya circumstellar disk traced back the disk emission as close as 0.1" ~ 6 AU from the star, the closest yet. Our results demonstrate the potential of the adaptive optics systems in achieving high-resolution and high-contrast imaging and thus in the study of circumstellar disks, envelopes and companions. 1. Introduction Young, nearby stars are our prime source of information to study the circum- stellar disk structure and evolution. They are also the ideal targets for adaptive optics (AO) observations, as they are usually bright enough to provide excellent wavefront reference.
  • Predicting Exoplanet Observability in Time, Contrast, Separation, and Polarization, in Scattered Light

    Predicting Exoplanet Observability in Time, Contrast, Separation, and Polarization, in Scattered Light

    A&A 578, A59 (2015) Astronomy DOI: 10.1051/0004-6361/201424202 & c ESO 2015 Astrophysics Predicting exoplanet observability in time, contrast, separation, and polarization, in scattered light Guillaume Schworer1;2 and Peter G. Tuthill2 1 LESIA, Observatoire de Paris, CNRS/UMR 8109, UPMC, Université Paris Diderot, 5 place J. Janssen, 92195 Meudon, France e-mail: [email protected] 2 Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006, Australia Received 14 May 2014 / Accepted 14 March 2015 ABSTRACT Context. Polarimetry is one of the keys to enhanced direct imaging of exoplanets. Not only does it deliver a differential observable pro- viding extra contrast, but when coupled with spectroscopy, it also reveals valuable information on the exoplanetary atmospheric com- position. Nevertheless, angular separation and contrast ratio to the host-star make for extremely challenging observation. Producing detailed predictions for exactly how the expected signals should appear is of critical importance for the designs and observational strategies of tomorrow’s telescopes. Aims. We aim at accurately determining the magnitudes and evolution of the main observational signatures for imaging an exoplanet: separation, contrast ratio to the host-star and polarization as a function of the orbital geometry and the reflectance parameters of the exoplanet. Methods. These parameters were used to construct a polarized-reflectance model based on the input of orbital parameters and two albedo values. The model is able to calculate a variety of observational predictions for exoplanets at any orbital time. Results. The inter-dependency of the three main observational criteria – angular separation, contrast ratio, polarization – result in a complex time-evolution of the system.
  • University of California Santa Cruz

    University of California Santa Cruz

    UNIVERSITY OF CALIFORNIA SANTA CRUZ BENEATH THE SURFACE OF GIANT PLANETS: EVOLUTION, STRUCTURE, AND COMPOSITION A dissertation submitted in partial satisfaction of the requirements for the degree of DOCTOR OF PHILOSOPHY in ASTRONOMY AND ASTROPHYSICS by Neil L Kelly Miller March 2013 The Dissertation of Neil L Kelly Miller is approved: Jonathan Fortney, Chair Professor D. Lin Professor P. Garaud Professor P. Bodenheimer Tyrus Miller Vice Provost and Dean of Graduate Studies Copyright c by Neil L Kelly Miller 2013 Table of Contents List of Figures v List of Tables xii Abstract xiii Dedication xv Acknowledgments xvi 1 Introduction 1 1.1 TheSolarSystemGiantPlanets . 3 1.2 FromIndividualSystemstoSamples . 4 1.3 Physical Processes in the Evolution of Giant Planets . ........ 8 2 Coupled Thermal and Tidal Evolution of Giant Expolanets 14 2.1 Abstract.................................... 14 2.2 Introduction.................................. 15 2.3 Model:Introduction ............................. 21 2.4 Model:Implementation ........................... 23 2.5 GeneralExamples .............................. 29 2.6 Results..................................... 37 2.6.1 SpecificSystems ........................... 37 2.6.2 SummaryforSuite .......................... 47 ′ 2.6.3 High Qs cases............................. 56 2.7 Discussion&Conclusions . 59 3 Applications of Giant Planet Thermal Evolution Model 74 3.1 Introduction.................................. 74 3.2 CoRoT-2b: Young Planet With Potentially Tidally Inflated Radius . 75 3.3 CoRoT-7b: Potential Evaporative Mass Loss Scenario . ....... 78 3.3.1 EvaporativeMassLossModel. 80 iii 3.3.2 PlanetEvolution ........................... 82 3.4 Kepler11 ................................... 82 3.4.1 Formation and Compositions of Kepler 11 Planets . 82 4 Measuring the Heavy Element Composition of Giant Exoplanets with Lower Irradiation 86 4.1 Abstract.................................... 86 4.2 Introduction.................................. 87 4.3 ModelandMethod.............................
  • Catalog of Nearby Exoplanets

    Catalog of Nearby Exoplanets

    Catalog of Nearby Exoplanets1 R. P. Butler2, J. T. Wright3, G. W. Marcy3,4, D. A Fischer3,4, S. S. Vogt5, C. G. Tinney6, H. R. A. Jones7, B. D. Carter8, J. A. Johnson3, C. McCarthy2,4, A. J. Penny9,10 ABSTRACT We present a catalog of nearby exoplanets. It contains the 172 known low- mass companions with orbits established through radial velocity and transit mea- surements around stars within 200 pc. We include 5 previously unpublished exo- planets orbiting the stars HD 11964, HD 66428, HD 99109, HD 107148, and HD 164922. We update orbits for 90 additional exoplanets including many whose orbits have not been revised since their announcement, and include radial ve- locity time series from the Lick, Keck, and Anglo-Australian Observatory planet searches. Both these new and previously published velocities are more precise here due to improvements in our data reduction pipeline, which we applied to archival spectra. We present a brief summary of the global properties of the known exoplanets, including their distributions of orbital semimajor axis, mini- mum mass, and orbital eccentricity. Subject headings: catalogs — stars: exoplanets — techniques: radial velocities 1Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the Uni- versity of California and the California Institute of Technology. The Keck Observatory was made possible by the generous financial support of the W. M. Keck Foundation. arXiv:astro-ph/0607493v1 21 Jul 2006 2Department of Terrestrial Magnetism, Carnegie Institute of Washington, 5241 Broad Branch Road NW, Washington, DC 20015-1305 3Department of Astronomy, 601 Campbell Hall, University of California, Berkeley, CA 94720-3411 4Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 5UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 6Anglo-Australian Observatory, PO Box 296, Epping.
  • Naming the Extrasolar Planets

    Naming the Extrasolar Planets

    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
  • Camp Marin Lecture Astro Chatter WASP Deadline

    Camp Marin Lecture Astro Chatter WASP Deadline

    WASP Warren Astronomical Society Paper Volume 31, Number 6 http://www.eaglequest.com/~bondono/WAS June, 1999 Camp Marin Lecture Astro Chatter by Steve Greene by Larry Kalinowski The Warren Astronomical Society was invited to lec- Not one planet, but three, were found circling Upsilon ture at Camp Narrin to 45 Girl Scouts and 15 adults on Andromedae, a fourth magnitude star that can be seen Saturday April 17. The lecture went very well even with with the naked eye, a third of the way between Almach the intense Michigan Nebulosity looming overhead and and M31. One of the planets is four times heavier than in fact falling on our head in the form of rain drops. The Jupiter, the lightest about .75 times. The innermost WAS members and Scouts in attendance persevered. planet has an orbit that carries it around its sun in 4.6 We initiated plan 'B', to take our presentation indoors. days. Two independent teams confirmed each others The audience of Scouts ranged in ages 7 to 14 and conclusions using completely different equipment. The were captivated by the telescopes, the literature, the planets very nearly occupy the same positions as video film and the discussion about astronomy. The Earth, Mars and Mercury, making present theories, scopes were placed near the windows to allow the about where giant gas planets should be from their Scouts look through at the tree tops and an active sun, obsolete. squirrel's nest high in the branches. This exercise pro- vided a way for the girls to understand how to look through a telescope so that when they have a chance see LARRY on page 2 on a dark clear night, their observa- tion of the heavens will be more fruitful.
  • CURRICULUM VITAE for DANIEL APAI Research Interests: Extrasolar Planets; Planet Formation; Planetary Atmospheres; Astrobiology; Space Telescope Architectures

    CURRICULUM VITAE for DANIEL APAI Research Interests: Extrasolar Planets; Planet Formation; Planetary Atmospheres; Astrobiology; Space Telescope Architectures

    CURRICULUM VITAE FOR DANIEL APAI Research Interests: Extrasolar Planets; Planet formation; Planetary atmospheres; Astrobiology; Space telescope architectures Professional Appointments 2017 – Associate Professor, Depts. of Astronomy and Planetary Sciences, Univ. of Arizona 2011 – 2017 Assistant Professor, Depts. of Astronomy and Planetary Sciences, Univ. Arizona 2008 – 2011 Assistant Astronomer, Space Telescope Science Institute Education 2004 PhD, University of Heidelberg and Max Planck Institute of Astronomy 2000 MSc in Physics, University of Szeged Recent International Service: Chair, HST–TESS Advisory Committee, Space Telescope Science Institute Science Advisory Committee member, Giant Magellan Telescope Executive Committee member, NASA Exoplanet Program Analysis Group (EXOPAG) Steering Committee member, NASA Nexus for Exoplanet System Science (NExSS) Chair, Exoplanet Science Questions for Direct Imaging Missions, SAG15/EXOPAG Member, Hubble Space Telescope Financial Review Committee Major Approved Programs as Principal Investigator 9 Hubble Space Telescope + 4 Spitzer Space Telescope programs, including: - Extrasolar Storms: Spitzer Exploration Science Program (1,144 Spitzer hour, 24 HST orbits) - Cloud Atlas: Hubble Space Telescope (112 orbits), 12+ refereed papers Earths in Other Solar Systems: $5.7M program (R&A), 45-member team, 140 refereed papers Nautilus: A large-aperture space telescope for a biosignature survey based on diffractive optics, Co-PI of $1.1M Gordon & Betty Moore Foundation grant Advising/Mentoring: Postdoc. Researchers
  • WASP Page 1 Hubble Eyes Aging Stars Science News, Vol. 148

    WASP Page 1 Hubble Eyes Aging Stars Science News, Vol. 148

    WASP Warren Astronomical Society Paper Volume 27, number 11 $1.00 for non-members November 1995 DATING THE COSMOS COMPUTER CHATTER ANNUAL HOLIDAY AWARDS Hubble eyes aging stars Larry F. Kalinowski Science News, Vol. 148, September 2,1995 submitted by Lorna Simmons Everyone knows you can't be older than your mother. But over the past year, observations with the Hubble Space Telescope and several other Comet DeVico has just passed perihelion in instruments seem to have contradicted this cardi- early October, so its beginning to fade from its maxi- nal rule. On the one hand, measurements of the mum brightness of 5.6. It was recovered in its seventy- speed at which the most distant galaxies are mov- four year orbit by independent comet observers Naka- ing from Earth suggest that the universe may be mura, Tanaka and Utsunomiya. It becomes a sixth no older than 8 billion to 12 billion years (SN: magnitude object on the night of the Macomb meeting, 10/8;94, p.232). On the other hand, astronomers October 19. Early reports say it has two tails. A morn- ing object, only, about fifteen degrees above the hori- estimate he ages of our galaxy's oldest stars at zon before twilight begins, it's easily observed as it 13 billion to 16 billion years. leaves Leo and enters the Ursa Major-Coma Berenices Now, new findings from Hubble may provide a area of the sky. However, it is quickly moving closer to step toward resolving this cosmic conundrum. the horizon and will become increasingly more difficult In viewing the globular cluster M4, the dense to observe during the rest of the month.
  • Fundamental Parameters of Wolf-Rayet Stars VI

    Fundamental Parameters of Wolf-Rayet Stars VI

    Astron. Astrophys. 320, 500–524 (1997) ASTRONOMY AND ASTROPHYSICS Fundamental parameters of Wolf-Rayet stars VI. Large Magellanic Cloud WNL stars? P.A.Crowther and L.J. Smith Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK Received 5 February 1996 / Accepted 26 June 1996 Abstract. We present a detailed, quantitative study of late WN Key words: stars: Wolf-Rayet;mass-loss; evolution; fundamen- (WNL) stars in the LMC, based on new optical spectroscopy tal parameters – galaxies: Magellanic Clouds (AAT, MSO) and the Hillier (1990) atmospheric model. In a pre- vious paper (Crowther et al. 1995a), we showed that 4 out of the 10 known LMC Ofpe/WN9 stars should be re-classified WN9– 10. We now present observations of the remaining stars (except the LBV R127), and show that they are also WNL (WN9–11) 1. Introduction stars, with the exception of R99. Our total sample consists of 17 stars, and represents all but one of the single LMC WN6– Quantitative studies of hot luminous stars in galaxies are im- 11 population and allows a direct comparison with the stellar portant for a number of reasons. First, and probably foremost, parameters and chemical abundances of Galactic WNL stars is the information they provide on the effect of the environment (Crowther et al. 1995b; Hamann et al. 1995a). Previously un- on such fundamental properties as the mass-loss rate and stellar published ultraviolet (HST-FOS, IUE-HIRES) spectroscopy are evolution. In the standard picture (e.g. Maeder & Meynet 1987) presented for a subset of our programme stars.
  • Habitability of Planets on Eccentric Orbits: Limits of the Mean Flux Approximation

    Habitability of Planets on Eccentric Orbits: Limits of the Mean Flux Approximation

    A&A 591, A106 (2016) Astronomy DOI: 10.1051/0004-6361/201628073 & c ESO 2016 Astrophysics Habitability of planets on eccentric orbits: Limits of the mean flux approximation Emeline Bolmont1, Anne-Sophie Libert1, Jeremy Leconte2; 3; 4, and Franck Selsis5; 6 1 NaXys, Department of Mathematics, University of Namur, 8 Rempart de la Vierge, 5000 Namur, Belgium e-mail: [email protected] 2 Canadian Institute for Theoretical Astrophysics, 60st St George Street, University of Toronto, Toronto, ON, M5S3H8, Canada 3 Banting Fellow 4 Center for Planetary Sciences, Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, ON, M1C 1A4, Canada 5 Univ. Bordeaux, LAB, UMR 5804, 33270 Floirac, France 6 CNRS, LAB, UMR 5804, 33270 Floirac, France Received 4 January 2016 / Accepted 28 April 2016 ABSTRACT Unlike the Earth, which has a small orbital eccentricity, some exoplanets discovered in the insolation habitable zone (HZ) have high orbital eccentricities (e.g., up to an eccentricity of ∼0.97 for HD 20782 b). This raises the question of whether these planets have surface conditions favorable to liquid water. In order to assess the habitability of an eccentric planet, the mean flux approximation is often used. It states that a planet on an eccentric orbit is called habitable if it receives on average a flux compatible with the presence of surface liquid water. However, because the planets experience important insolation variations over one orbit and even spend some time outside the HZ for high eccentricities, the question of their habitability might not be as straightforward. We performed a set of simulations using the global climate model LMDZ to explore the limits of the mean flux approximation when varying the luminosity of the host star and the eccentricity of the planet.
  • Kuchner, M. & Seager, S., Extrasolar Carbon Planets, Arxiv:Astro-Ph

    Kuchner, M. & Seager, S., Extrasolar Carbon Planets, Arxiv:Astro-Ph

    Extrasolar Carbon Planets Marc J. Kuchner1 Princeton University Department of Astrophysical Sciences Peyton Hall, Princeton, NJ 08544 S. Seager Carnegie Institution of Washington, 5241 Broad Branch Rd. NW, Washington DC 20015 [email protected] ABSTRACT We suggest that some extrasolar planets . 60 ML will form substantially from silicon carbide and other carbon compounds. Pulsar planets and low-mass white dwarf planets are especially good candidate members of this new class of planets, but these objects could also conceivably form around stars like the Sun. This planet-formation pathway requires only a factor of two local enhancement of the protoplanetary disk’s C/O ratio above solar, a condition that pileups of carbonaceous grains may create in ordinary protoplanetary disks. Hot, Neptune- mass carbon planets should show a significant paucity of water vapor in their spectra compared to hot planets with solar abundances. Cooler, less massive carbon planets may show hydrocarbon-rich spectra and tar-covered surfaces. The high sublimation temperatures of diamond, SiC, and other carbon compounds could protect these planets from carbon depletion at high temperatures. arXiv:astro-ph/0504214v2 2 May 2005 Subject headings: astrobiology — planets and satellites, individual (Mercury, Jupiter) — planetary systems: formation — pulsars, individual (PSR 1257+12) — white dwarfs 1. INTRODUCTION The recent discoveries of Neptune-mass extrasolar planets by the radial velocity method (Santos et al. 2004; McArthur et al. 2004; Butler et al. 2004) and the rapid development 1Hubble Fellow –2– of new technologies to study the compositions of low-mass extrasolar planets (see, e.g., the review by Kuchner & Spergel 2003) have compelled several authors to consider planets with chemistries unlike those found in the solar system (Stevenson 2004) such as water planets (Kuchner 2003; Leger et al.
  • PDF) Submittals Are Preferred) and Information Particle and Astroparticle Physics As Well As Accelerator Physics

    PDF) Submittals Are Preferred) and Information Particle and Astroparticle Physics As Well As Accelerator Physics

    CERNNovember/December 2019 cerncourier.com COURIERReporting on international high-energy physics WELCOME CERN Courier – digital edition Welcome to the digital edition of the November/December 2019 issue of CERN Courier. The Extremely Large Telescope, adorning the cover of this issue, is due to EXTREMELY record first light in 2025 and will outperform existing telescopes by orders of magnitude. It is one of several large instruments to look forward to in the decade ahead, which will also see the start of high-luminosity LHC operations. LARGE TELESCOPE As the 2020s gets under way, the Courier will be reviewing the LHC’s 10-year physics programme so far, as well as charting progress in other domains. In the meantime, enjoy news of KATRIN’s first limit on the neutrino mass (p7), a summary of the recently published European strategy briefing book (p8), the genesis of a hadron-therapy centre in Southeast Europe (p9), and dispatches from the most interesting recent conferences (pp19—23). CLIC’s status and future (p41), the abstract world of gauge–gravity duality (p44), France’s particle-physics origins (p37) and CERN’s open days (p32) are other highlights from this last issue of the decade. Enjoy! To sign up to the new-issue alert, please visit: http://comms.iop.org/k/iop/cerncourier To subscribe to the magazine, please visit: https://cerncourier.com/p/about-cern-courier KATRIN weighs in on neutrinos Maldacena on the gauge–gravity dual FPGAs that speak your language EDITOR: MATTHEW CHALMERS, CERN DIGITAL EDITION CREATED BY IOP PUBLISHING CCNovDec19_Cover_v1.indd 1 29/10/2019 15:41 CERNCOURIER www.