Sara Seager. Introduction. Professor Seager's main research goal is to find and identify another Earth, including the search for signs of life by way of biosignature gases. First things, first, and so we start with an introduction. These planets are called “exoplanets”. Professor Seager’s favorite exoplanet diagram is the mass- period diagram shown to the right. This diagram shows that exoplanets have all masses and semi- major axes possible, showcasing the random nature of planet formation and migration. The different planet detection techniques are shown in the diagram. Second Generation Exoplanet Atmospheres Highlights: The first paper on exoplanet atmosphere retrieval (led by then PhD student N. Physics Of Atmospheres Pdf FileParts of the diagram with no planets are where technology can not yet reach exoplanets. The paucity of planets of Earth's size or mass and orbit emphasizes the challenge exo. Earth discovery with any planet- discovery technique. E-Book:Physics of Atmospheres Category:Atmospheric Physics Autor:John T. Houghton Editor:- Rating:5 of 5 stars Counts:3631 Original Format:Paperback Download Formats:PDF, FB2, DJVU Publication date: Publication City. Physics Of Atmospheres. 11-09-2016 2/2 Physics Of Atmospheres. Other Files Available to Download Physics Of Atmospheres. 9-09-2016 2/2 Physics Of Atmospheres. Other Files Available to Download Batalha, PNAS 2. 01. Exoplanet Atmospheres. The goal in studying exoplanet atmospheres is to understand the atmospheric composition and temperature. We want to be able to recognize planet atmospheres like Earth’s: with water vapor, oxygen, ozone, and carbon dioxide. These strong absorbers would make the major contributions to the spectrum we could observe from afar. While the detection of true Earth twins is some time off, we are busy trying to understand hot Jupiter and hot Neptune atmospheres observed by primary and secondary eclipses for transiting exoplanets. Professor Seager’s group’s research focuses on computer models of exoplanet atmospheres and interpretation of data from space telescopes. First Generation Exoplanet Atmospheres Highlights: The first paper on hot Jupiter atmospheres.
Physics Of Atmospheres Pdf EditorSeager, S., & Sasselov, D. Extrasolar Giant Planets Under Strong Stellar Irradiation”, Ap. J, 5. 02, L1. 57- 1. View PDFThe first description of exoplanet transmission spectra, that led to the first detection of an exoplanet atmosphere. Seager, S., & Sasselov, D. Theoretical Transmission Spectra During an Extrasolar Giant Planet Transit”, Ap. J, 5. 37, 9. 16- 9. J., & Harrington, J. Detection of Infrared Radiation from an Extrasolar Planet”, Nature, 4. View PDFFirst general description of super Earth atmospheres, lead by Prof. Seager’s student Eliza Miller- Ricci. Miller- Ricci, E., Seager, S., & Sasselov, D. The Atmospheric Signatures of Super- Earths: How to Distinguish Between Hydrogen- Rich and Hydrogen- Poor Atmospheres”, Ap. J, 6. 90, 1. 05. 6- 1. Madhusudhan). Madhusudhan, N. A Temperature and Abundance Retrieval Method for Exoplanet Atmospheres”, Ap. J, 7. 07, 2. 4- 3. View PDFOne of the modern cornerstones of modern exoplanet atmospheric retrieval (led by then Ph. D student Bjoern Benneke). Benneke, B., & Seager, S. Atmospheric Retrieval for Super- Earths: Uniquely Constraining the Atmospheric Composition with Transmission Spectroscopy”, Ap. J, 7. 53, 1. 00- 1. Constraining Exoplanet Mass from Transmission Spectroscopy”, Science, 3. View PDFA photochemistry code constructed from scratch for exoplanets, with several applications under either reduced or oxidized conditions. We hope to make it available in python in the future (led by then Ph. D student Renyu Hu). Hu, R., Seager, S., & Bains, W. Photochemistry in Terrestrial Exoplanet Atmospheres. Photochemistry Model and Benchmark Cases”, Ap. J, 7. 61, 1. 66- 1. Professor Seager’s work has focused on the mass- radius relationships for exoplanets of a wide range of compositions and masses. Seager and colleagues. Exoplanet researchers have realized that there are fatal limitations to uncovering the interior composition of an exoplanet because only the mass and radius can be measured—no other information about the interior. Seager’s most significant papers on exoplanet interiors. Explanation of why the mass- radius relationships for planets of any composition are similar. Seager, S., Kuchner, M., Hier- Majumder, C. A., & Militzer, 2. Mass- Radius Relationship for Solid Exoplanets. This paper was rejected from the Ap. J and Marc and I moved on to other things. We decided to let the paper live on astroph Kuchner, M. View PDFExoplanet Biosignatures and Earth Twin Planets Biosignatures are signs of life in an exoplanet atmosphere or on an exoplanet surface. Earth’s biosignatures are oxygen (produced only in large quantities by plants and photosynthetic bacteria) and ozone (photochemically produced in the atmosphere from oxygen). Nitrous oxide is an atmospheric gas also produced by life, but is difficult to detect. Methane is produced both biologically and from mid- ocean ridge volcanism. Water vapor is considered a sign of habitability, because all life on Earth needs liquid water; atmospheric water vapor is indicative of liquid water oceans for terrestrial- like planets. Earth twins refer to planets just like Earth, orbiting sun- like stars with liquid water oceans, continents, and thin atmospheres. Co- authored the first paper describing how to use an Earth- twin’s reflected light curve to determine the rotation rate and possibly infer the presence of weather and continents. Ford, E. B., Seager, S., & Turner, E. Characterization of Extrasolar Terrestrial Planets from Diurnal Photometric Variability”, Nature, 4. Read More.. Updated at. Palle, E., Ford, E. B., Seager, S., Montanes- Rodriguez, P., & Vazquez, M. Identifying the Rotation Rate and the Presence of Dynamic Weather on Extrasolar Earth- like Planets from Photometric Observations”, Ap. J, 6. 76, 1. 31. 9- 1. View PDFA very useful paper summarizing Earth’s biosignatures (in which Prof. Seager played only a minor role)Des Marais, D. J., Harwit, M., Jucks, K., Kasting, J. I., Lin, D., Seager, S., Schneider, J., Traub, W., & Woolf, N. Remote Sensing of Planetary Properties and Biosignatures on Extrasolar Terrestrial Planets”, Astrobiology, 2, 1. View PDFSeager’s main work on exoplanet biosignatures is in progress. Exoplanet Other. Professor Seager has worked on a variety of other topics in exoplanets. Seager's favorite papers is about how to extract information from a transit light curve, by recognizing that there are five equations and five unknowns for a circular orbit. Surprisingly, a star's density can be measured from the planet transit light curve. This work spawned became highly relevant after the Kepler space telescope was launched, providing the high- precision photometry needed for the applications described in this paper. Seager, S., & Mallen- Ornelas, G. On the Unique Solution of Planet and Star Parameters from an Extrasolar Planet Transit Light Curve”, Ap. J, 5. 85, 1. 03. 8- 1. View PDFShe also published the first paper on constraining exoplanet rotation rates from oblateness measurements during transit. Seager, S., & Hui, L. Constraining the Rotation Rate of Transiting Extrasolar Planets by an Oblateness Measurement”, Ap. J, 5. 74, 1. 00. 4- 1. View PDF An early paper on reflected light phase curves and polarization signatures. Seager, S., Whitney, B. A., & Sasselov, D. Light Curves and Polarization of the Close- in Extrasolar Giant Planets”, Ap. J, 5. 40, 5. 04- 5. View PDFAnd co- authored the first and to date only paper in exoplanet atmospheric refraction. Hui, L., & Seager, S. Atmospheric Lensing and Oblateness Effect During an Extrasolar Planetary Transit”, Ap. J, 5. 72, 5. 40- 5. View PDF Exoplanet Space Telescopes ASTERIA. Prof. Seager is PI of ASTERIA (formerly a 3. U Cube. Sat called Exoplanet. Sat). ASTERIA is a 6. U Cube. Sat, a space telescope capable of high photometric precision on bright stars, whose program includes the search for transiting exoplanets, both new transits of known radial velocity planets as well as new discoveries. The prototype is being implemented at JPL and is a partnership with Draper Labs. The scientific goal is ultimately a search for transiting Earth- size planetse around the nearest, brightest, sun- like stars. The engineering goal is a fleet of small space telescopes, each observing its own host star. Seager is a co- I on TESS, an MIT- led NASA mission to be launched in 2. TESS will find thousands of exoplaents, including hundreds of small planets transting M dwarf stars. Seager was a Participating Scientist with Kepler, and her group studied hot Jupiters with Kepler data. Noteable papers are below. B., and 4 coauthors, . This research field has seen a resurgence with the upcoming launch of ESA’s Planck Space Telescope. Seager is no longer actively working in this field of research. Seager’s major contribution to recombination in the early Universe is in the form of two papers: A summary paper. Seager, S., Sasselov, D. A New Calculation of the Recombination Epoch”, 1. Ap. J, 5. 23, L1- 5. View PDFand the full description. Seager, S., Sasselov, D. How Exactly Did the Universe Become Neutral?”, Ap. JS, 1. 28, 4. 07- 4.
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