Eric Agol – Bibliography
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Exploring Exoplanet Populations with NASA's Kepler Mission
SPECIAL FEATURE: PERSPECTIVE PERSPECTIVE SPECIAL FEATURE: Exploring exoplanet populations with NASA’s Kepler Mission Natalie M. Batalha1 National Aeronautics and Space Administration Ames Research Center, Moffett Field, 94035 CA Edited by Adam S. Burrows, Princeton University, Princeton, NJ, and accepted by the Editorial Board June 3, 2014 (received for review January 15, 2014) The Kepler Mission is exploring the diversity of planets and planetary systems. Its legacy will be a catalog of discoveries sufficient for computing planet occurrence rates as a function of size, orbital period, star type, and insolation flux.The mission has made significant progress toward achieving that goal. Over 3,500 transiting exoplanets have been identified from the analysis of the first 3 y of data, 100 planets of which are in the habitable zone. The catalog has a high reliability rate (85–90% averaged over the period/radius plane), which is improving as follow-up observations continue. Dynamical (e.g., velocimetry and transit timing) and statistical methods have confirmed and characterized hundreds of planets over a large range of sizes and compositions for both single- and multiple-star systems. Population studies suggest that planets abound in our galaxy and that small planets are particularly frequent. Here, I report on the progress Kepler has made measuring the prevalence of exoplanets orbiting within one astronomical unit of their host stars in support of the National Aeronautics and Space Admin- istration’s long-term goal of finding habitable environments beyond the solar system. planet detection | transit photometry Searching for evidence of life beyond Earth is the Sun would produce an 84-ppm signal Translating Kepler’s discovery catalog into one of the primary goals of science agencies lasting ∼13 h. -
FY08 Technical Papers by GSMTPO Staff
AURA/NOAO ANNUAL REPORT FY 2008 Submitted to the National Science Foundation July 23, 2008 Revised as Complete and Submitted December 23, 2008 NGC 660, ~13 Mpc from the Earth, is a peculiar, polar ring galaxy that resulted from two galaxies colliding. It consists of a nearly edge-on disk and a strongly warped outer disk. Image Credit: T.A. Rector/University of Alaska, Anchorage NATIONAL OPTICAL ASTRONOMY OBSERVATORY NOAO ANNUAL REPORT FY 2008 Submitted to the National Science Foundation December 23, 2008 TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................................. 1 1 SCIENTIFIC ACTIVITIES AND FINDINGS ..................................................................................... 2 1.1 Cerro Tololo Inter-American Observatory...................................................................................... 2 The Once and Future Supernova η Carinae...................................................................................................... 2 A Stellar Merger and a Missing White Dwarf.................................................................................................. 3 Imaging the COSMOS...................................................................................................................................... 3 The Hubble Constant from a Gravitational Lens.............................................................................................. 4 A New Dwarf Nova in the Period Gap............................................................................................................ -
Formation of TRAPPIST-1
EPSC Abstracts Vol. 11, EPSC2017-265, 2017 European Planetary Science Congress 2017 EEuropeaPn PlanetarSy Science CCongress c Author(s) 2017 Formation of TRAPPIST-1 C.W Ormel, B. Liu and D. Schoonenberg University of Amsterdam, The Netherlands ([email protected]) Abstract start to drift by aerodynamical drag. However, this growth+drift occurs in an inside-out fashion, which We present a model for the formation of the recently- does not result in strong particle pileups needed to discovered TRAPPIST-1 planetary system. In our sce- trigger planetesimal formation by, e.g., the streaming nario planets form in the interior regions, by accre- instability [3]. (a) We propose that the H2O iceline (r 0.1 au for TRAPPIST-1) is the place where tion of mm to cm-size particles (pebbles) that drifted ice ≈ the local solids-to-gas ratio can reach 1, either by from the outer disk. This scenario has several ad- ∼ vantages: it connects to the observation that disks are condensation of the vapor [9] or by pileup of ice-free made up of pebbles, it is efficient, it explains why the (silicate) grains [2, 8]. Under these conditions plan- TRAPPIST-1 planets are Earth mass, and it provides etary embryos can form. (b) Due to type I migration, ∼ a rationale for the system’s architecture. embryos cross the iceline and enter the ice-free region. (c) There, silicate pebbles are smaller because of col- lisional fragmentation. Nevertheless, pebble accretion 1. Introduction remains efficient and growth is fast [6]. (d) At approx- TRAPPIST-1 is an M8 main-sequence star located at a imately Earth masses embryos reach their pebble iso- distance of 12 pc. -
Last Time: Planet Finding
Last Time: Planet Finding • Radial velocity method • Parent star’s Doppler shi • Planet minimum mass, orbital period, semi- major axis, orbital eccentricity • UnAl Kepler Mission, was the method with the most planets Last Time: Planet Finding • Transits – eclipse of the parent star: • Planetary radius, orbital period, semi-major axis • Now the most common way to find planets Last Time: Planet Finding • Direct Imaging • Planetary brightness, distance from parent star at that moment • About 10 planets detected Last Time: Planet Finding • Lensing • Planetary mass and, distance from parent star at that moment • You want to look towards the center of the galaxy where there is a high density of stars Last Time: Planet Finding • Astrometry • Tiny changes in star’s posiAon are not yet measurable • Would give you planet’s mass, orbit, and eccentricity One more important thing to add: • Giant planets (which are easiest to detect) are preferenAally found around stars that are abundant in iron – “metallicity” • Iron is the easiest heavy element to measure in a star • Heavy-element rich planetary systems make planets more easily 13.2 The Nature of Extrasolar Planets Our goals for learning: • What have we learned about extrasolar planets? • How do extrasolar planets compare with planets in our solar system? Measurable Properties • Orbital period, distance, and orbital shape • Planet mass, size, and density • Planetary temperature • Composition Orbits of Extrasolar Planets • Nearly all of the detected planets have orbits smaller than Jupiter’s. • This is a selection effect: Planets at greater distances are harder to detect with the Doppler technique. Orbits of Extrasolar Planets • Orbits of some extrasolar planets are much more elongated (have a greater eccentricity) than those in our solar system. -
Circumbinary Habitable Zones in the Presence of a Giant Planet
Circumbinary habitable zones in the presence of a giant planet Nikolaos Georgakarakos 1;2;∗, Siegfried Eggl 4;5;6;7 and Ian Dobbs-Dixon 1;2;3 1 Division of Science, New York University Abu Dhabi, Abu Dhabi, UAE 2Center for Astro, Particle and Planetary Physics (CAP3), New York University Abu Dhabi,UAE 3Center for Space Sciences, New York University Abu Dhabi,UAE 4Department of Astronomy, University of Washington, Seattle, WA, USA 5Vera C. Rubin Observatory, Tucson, Arizona, USA 6Department of Aerospace Engineering, University of Chicago at Urbana-Champaign, Urbana, IL, USA 7IMCCE, Observatoire de Paris, Paris, France Correspondence*: Nikolaos Georgakarakos [email protected] ABSTRACT Determining habitable zones in binary star systems can be a challenging task due to the combination of perturbed planetary orbits and varying stellar irradiation conditions. The concept of “dynamically informed habitable zones” allows us, nevertheless, to make predictions on where to look for habitable worlds in such complex environments. Dynamically informed habitable zones have been used in the past to investigate the habitability of circumstellar planets in binary systems and Earth-like analogs in systems with giant planets. Here, we extend the concept to potentially habitable worlds on circumbinary orbits. We show that habitable zone borders can be found analytically even when another giant planet is present in the system. By applying this methodology to Kepler-16, Kepler-34, Kepler-35, Kepler-38, Kepler-64, Kepler-413, Kepler-453, Kepler-1647 and Kepler-1661 we demonstrate that the presence of the known giant planets in the majority of those systems does not preclude the existence of potentially habitable worlds. -
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. -
Survival of Satellites During the Migration of a Hot Jupiter: the Influence of Tides
EPSC Abstracts Vol. 13, EPSC-DPS2019-1590-1, 2019 EPSC-DPS Joint Meeting 2019 c Author(s) 2019. CC Attribution 4.0 license. Survival of satellites during the migration of a Hot Jupiter: the influence of tides Emeline Bolmont (1), Apurva V. Oza (2), Sergi Blanco-Cuaresma (3), Christoph Mordasini (2), Pierre Auclair-Desrotour (2), Adrien Leleu (2) (1) Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, CH-1290 Sauverny, Switzerland ([email protected]) (2) Physikalisches Institut, Universität Bern, Gesellschaftsstr. 6, 3012, Bern, Switzerland (3) Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA Abstract 2. The model We explore the origin and stability of extrasolar satel- lites orbiting close-in gas giants, by investigating if the Tidal interactions 1 M⊙ satellite can survive the migration of the planet in the 1 MIo protoplanetary disk. To accomplish this objective, we 1 MJup used Posidonius, a N-Body code with an integrated tidal model, which we expanded to account for the migration of the gas giant in a disk. Preliminary re- Inner edge of disk: ain sults suggest the survival of the satellite is rare, which Type 2 migration: !mig would indicate that if such satellites do exist, capture is a more likely process. Figure 1: Schema of the simulation set up: A Io-like satellite orbits around a Jupiter-like planet with a solar- 1. Introduction like host star. Satellites around Hot Jupiters were first thought to be lost by falling onto their planet over Gyr timescales (e.g. [1]). This is due to the low tidal dissipation factor of Jupiter (Q 106, [10]), likely to be caused by the 2.1. -
Planet Hunters. VI: an Independent Characterization of KOI-351 and Several Long Period Planet Candidates from the Kepler Archival Data
Accepted to AJ Planet Hunters VI: An Independent Characterization of KOI-351 and Several Long Period Planet Candidates from the Kepler Archival Data1 Joseph R. Schmitt2, Ji Wang2, Debra A. Fischer2, Kian J. Jek7, John C. Moriarty2, Tabetha S. Boyajian2, Megan E. Schwamb3, Chris Lintott4;5, Stuart Lynn5, Arfon M. Smith5, Michael Parrish5, Kevin Schawinski6, Robert Simpson4, Daryll LaCourse7, Mark R. Omohundro7, Troy Winarski7, Samuel Jon Goodman7, Tony Jebson7, Hans Martin Schwengeler7, David A. Paterson7, Johann Sejpka7, Ivan Terentev7, Tom Jacobs7, Nawar Alsaadi7, Robert C. Bailey7, Tony Ginman7, Pete Granado7, Kristoffer Vonstad Guttormsen7, Franco Mallia7, Alfred L. Papillon7, Franco Rossi7, and Miguel Socolovsky7 [email protected] ABSTRACT We report the discovery of 14 new transiting planet candidates in the Kepler field from the Planet Hunters citizen science program. None of these candidates overlapped with Kepler Objects of Interest (KOIs) at the time of submission. We report the discovery of one more addition to the six planet candidate system around KOI-351, making it the only seven planet candidate system from Kepler. Additionally, KOI-351 bears some resemblance to our own solar system, with the inner five planets ranging from Earth to mini-Neptune radii and the outer planets being gas giants; however, this system is very compact, with all seven planet candidates orbiting . 1 AU from their host star. A Hill stability test and an orbital integration of the system shows that the system is stable. Furthermore, we significantly add to the population of long period 1This publication has been made possible through the work of more than 280,000 volunteers in the Planet Hunters project, whose contributions are individually acknowledged at http://www.planethunters.org/authors. -
The Minor Planet Bulletin
THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 36, NUMBER 3, A.D. 2009 JULY-SEPTEMBER 77. PHOTOMETRIC MEASUREMENTS OF 343 OSTARA Our data can be obtained from http://www.uwec.edu/physics/ AND OTHER ASTEROIDS AT HOBBS OBSERVATORY asteroid/. Lyle Ford, George Stecher, Kayla Lorenzen, and Cole Cook Acknowledgements Department of Physics and Astronomy University of Wisconsin-Eau Claire We thank the Theodore Dunham Fund for Astrophysics, the Eau Claire, WI 54702-4004 National Science Foundation (award number 0519006), the [email protected] University of Wisconsin-Eau Claire Office of Research and Sponsored Programs, and the University of Wisconsin-Eau Claire (Received: 2009 Feb 11) Blugold Fellow and McNair programs for financial support. References We observed 343 Ostara on 2008 October 4 and obtained R and V standard magnitudes. The period was Binzel, R.P. (1987). “A Photoelectric Survey of 130 Asteroids”, found to be significantly greater than the previously Icarus 72, 135-208. reported value of 6.42 hours. Measurements of 2660 Wasserman and (17010) 1999 CQ72 made on 2008 Stecher, G.J., Ford, L.A., and Elbert, J.D. (1999). “Equipping a March 25 are also reported. 0.6 Meter Alt-Azimuth Telescope for Photometry”, IAPPP Comm, 76, 68-74. We made R band and V band photometric measurements of 343 Warner, B.D. (2006). A Practical Guide to Lightcurve Photometry Ostara on 2008 October 4 using the 0.6 m “Air Force” Telescope and Analysis. Springer, New York, NY. located at Hobbs Observatory (MPC code 750) near Fall Creek, Wisconsin. -
Astrobiology and the Search for Life Beyond Earth in the Next Decade
Astrobiology and the Search for Life Beyond Earth in the Next Decade Statement of Dr. Andrew Siemion Berkeley SETI Research Center, University of California, Berkeley ASTRON − Netherlands Institute for Radio Astronomy, Dwingeloo, Netherlands Radboud University, Nijmegen, Netherlands to the Committee on Science, Space and Technology United States House of Representatives 114th United States Congress September 29, 2015 Chairman Smith, Ranking Member Johnson and Members of the Committee, thank you for the opportunity to testify today. Overview Nearly 14 billion years ago, our universe was born from a swirling quantum soup, in a spectacular and dynamic event known as the \big bang." After several hundred million years, the first stars lit up the cosmos, and many hundreds of millions of years later, the remnants of countless stellar explosions coalesced into the first planetary systems. Somehow, through a process still not understood, the laws of physics guiding the unfolding of our universe gave rise to self-replicating organisms − life. Yet more perplexing, this life eventually evolved a capacity to know its universe, to study it, and to question its own existence. Did this happen many times? If it did, how? If it didn't, why? SETI (Search for ExtraTerrestrial Intelligence) experiments seek to determine the dis- tribution of advanced life in the universe through detecting the presence of technology, usually by searching for electromagnetic emission from communication technology, but also by searching for evidence of large scale energy usage or interstellar propulsion. Technology is thus used as a proxy for intelligence − if an advanced technology exists, so to does the ad- vanced life that created it. -
CASKAR: a CASPER Concept for the SKA Phase 1 Signal Processing Sub-System
CASKAR: A CASPER concept for the SKA phase 1 Signal Processing Sub-system Francois Kapp, SKA SA Outline • Background • Technical – Architecture – Power • Cost • Schedule • Challenges/Risks • Conclusions Background CASPER Technology MeerKAT Who is CASPER? • Berkeley Wireless Research Center • Nancay Observatory • UC Berkeley Radio Astronomy Lab • Oxford University Astrophysics • UC Berkeley Space Sciences Lab • Metsähovi Radio Observatory, Helsinki University of • Karoo Array Telescope / SKA - SA Technology • NRAO - Green Bank • New Jersey Institute of Technology • NRAO - Socorro • West Virginia University Department of Physics • Allen Telescope Array • University of Iowa Department of Astronomy and • MIT Haystack Observatory Physics • Harvard-Smithsonian Center for Astrophysics • Ohio State University Electroscience Lab • Caltech • Hong Kong University Department of Electrical and Electronic Engineering • Cornell University • Hartebeesthoek Radio Astronomy Observatory • NAIC - Arecibo Observatory • INAF - Istituto di Radioastronomia, Northern Cross • UC Berkeley - Leuschner Observatory Radiotelescope • Giant Metrewave Radio Telescope • University of Manchester, Jodrell Bank Centre for • Institute of Astronomy and Astrophysics, Academia Sinica Astrophysics • National Astronomical Observatories, Chinese Academy of • Submillimeter Array Sciences • NRAO - Tucson / University of Arizona Department of • CSIRO - Australia Telescope National Facility Astronomy • Parkes Observatory • Center for Astrophysics and Supercomputing, Swinburne University -
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.