In this book, renowned scientists describe the various techniques used to detect and characterize extrasolar planets, or exoplanets, with a view to unveiling the “tricks of the trade” of planet detection to a wider community. The radial velocity method, transit method, microlensing method, and direct imaging method are all clearly explained, drawing attention to their advantages and limitations and highlighting the complementary roles that they can play in improving the characterization of exoplanets’ physical and orbital properties. By probing the planetary frequency at different distances and in different conditions, these techniques are helping astrophysicists to reconstruct the scenarios of planetary formation and to give robust scientific answers to questions regarding the frequency of potentially habitable worlds. Twenty years have passed since the discovery of a Jupiter-mass companion to a main sequence star other than the Sun, heralding the birth of extrasolar planetary research; this book fully conveys the exciting progress that has been achieved during the intervening period.
The past decade has delivered remarkable discoveries in the study of exoplanets. Hand-in-hand with these advances, a theoretical understanding of the myriad of processes that dictate the formation and evolution of planets has matured, spurred on by the avalanche of unexpected discoveries. Appreciation of the factors that make a planet hospitable to life has grown in sophistication, as has understanding of the context for biosignatures, the remotely detectable aspects of a planet's atmosphere or surface that reveal the presence of life. Exoplanet Science Strategy highlights strategic priorities for large, coordinated efforts that will support the scientific goals of the broad exoplanet science community. This report outlines a strategic plan that will answer lingering questions through a combination of large, ambitious community-supported efforts and support for diverse, creative, community-driven investigator research.
The study of exoplanets is one of the most vibrant fields of astrophysics today. Precise radial velocity (RV, or Doppler) measurements created the field by discovering the first exoplanets. Although employed for more than 30 years, RV measurements are still relevant today; when used with the transit method it provides the first characterization of exoplanets in terms of its mass, radius, and bulk density. These provide the first clues as to the internal structure of the exoplanet. With this text, Hatzes provides a deep understanding of the Doppler method, including how to achieve RV measurement precision, as well as the challenges, limitations, and potential of the technique. It also covers other aspects of the method such instrumentation, wavelength calibration, finding periodic signals in RV time series, signal interpretation, and Keplerian orbits. It's an essential reference for researchers and graduate students in the field of exoplanets, and additionally stellar spectroscopists and instrumentalists.
An authoritative primer on the cutting-edge science of planet hunting Alien worlds have long been a staple of science fiction. But today, thanks to modern astronomical instrumentation and the achievements of many enterprising observational astronomers, the existence of planets outside our solar system—also known as exoplanets—has moved into the realm of science fact. With planet hunters finding ever smaller, more Earth-like worlds, our understanding of the cosmos is forever changed, yet the question of how astronomers make these discoveries often goes unanswered. How Do You Find an Exoplanet? is an authoritative primer on the four key techniques that today's planet hunters use to detect the feeble signals of planets orbiting distant stars. John Johnson provides you with an insider’s perspective on this exciting cutting-edge science, showing how astronomers detect the wobble of stars caused by the gravitational tug of an orbiting planet, the slight diminution of light caused by a planet eclipsing its star, and the bending of space-time by stars and their planets, and how astronomers even directly take pictures of planets next to their bright central stars. Accessible to anyone with a basic foundation in college-level physics, How Do You Find an Exoplanet? sheds new light on the prospect of finding life outside our solar system, how surprising new observations suggest that we may not fully understand how planets form, and much more.
This up-to-date resource is based on lectures developed by experts in the relevant fields and carefully edited by the leading astrobiologists within the European community. Aimed at graduate students in physics, astronomy and biology and their lecturers, the text begins with a general introduction to astrobiology, followed by sections on basic prebiotic chemistry, extremophiles, and habitability in our solar system and beyond. A discussion of astrodynamics leads to a look at experimental facilities and instrumentation for space experiments and, ultimately, astrobiology missions, backed in each case by the latest research results from this fascinating field. Includes a CD-ROM with additional course material.
Exoplanets: Finding, Exploring, and Understanding Alien Worlds probes the basis for possible answers to the fundamentals questions asked about these planets orbiting stars other than our Sun. This book examines what such planets might be like, where they are, and how we find them. Until around ten years ago, the only planets that we knew about were within the Solar System. The first genuine planet beyond the confines of the Solar System was discovered only 1988. Since then another 350 or so exoplanets have been detected by various methods, and most of these haven been found in the last ten years. Although many more exoplanets discoveries may be expected to occur even as this book is being read, a large enough data set is now available to form the basis for an informed general account of exoplanets. The topic hence is an extremely "hot" one - all the more so because the recently launched Kepler spacecraft should soon start uncovering many more exoplanets, some perhaps comparable with the Earth (and therefore possibly alternative homes for mankind, if we could ever reach them). Exoplanets: Finding, Exploring, and Understanding Alien Life gives a comprehensive, balances, and above all accurate account of exoplanets.
Over the past twenty years, astronomers have identified hundreds of extrasolar planets--planets orbiting stars other than the sun. Recent research in this burgeoning field has made it possible to observe and measure the atmospheres of these exoplanets. This is the first textbook to describe the basic physical processes--including radiative transfer, molecular absorption, and chemical processes--common to all planetary atmospheres, as well as the transit, eclipse, and thermal phase variation observations that are unique to exoplanets. In each chapter, Sara Seager offers a conceptual introduction, examples that combine the relevant physics equations with real data, and exercises. Topics range from foundational knowledge, such as the origin of atmospheric composition and planetary spectra, to more advanced concepts, such as solutions to the radiative transfer equation, polarization, and molecular and condensate opacities. Since planets vary widely in their atmospheric properties, Seager emphasizes the major physical processes that govern all planetary atmospheres. Moving from first principles to cutting-edge research, Exoplanet Atmospheres is an ideal resource for students and researchers in astronomy and earth sciences, one that will help prepare them for the next generation of planetary science. The first textbook to describe exoplanet atmospheres Illustrates concepts using examples grounded in real data Provides a step-by-step guide to understanding the structure and emergent spectrum of a planetary atmosphere Includes exercises for students
The transit method of detecting exoplanets has dominated the search for distant worlds since the success of the Kepler space telescope and will continue to lead the field after the launch of the Transiting Exoplanet Survey Satellite in 2018. But detections are just the beginning. Transit light curves can only reveal a limited amount of information about a planet, and that information is almost entirely dependent on the properties of the host star or stars. This dissertation discusses follow-up techniques to more precisely characterize transiting planets using photometric observations.A high-resolution follow-up imaging program using the Hubble Space Telescope (HST) searched for previously unknown stars nearby the hosts of small and cool Kepler exoplanets and observed a higher-than-expected occurrence rate of stellar multiplicity. The rate of previously unknown stellar multiples has strong implications for the size and habitability of the orbiting planets. Three systems with newly discovered stellar multiplicity, Kepler-296 (2 stars, 5 planets), KOI-2626 (3 stars, 1 planet), and KOI-3049 (2 stars, 1 planet), were characterized in more detail. In the cases of Kepler-296 and KOI-2626, some of the planets lost their previous habitable zone status because of host star ambiguity.Next, the ultra-short period, ultra-hot Jupiter WASP-103b was used as a case study to test for the presence of a stratospheric temperature inversion through dayside emission spectroscopy using HST. WASP-103bs near-infrared emission spectrum is consistent with an isothermal or thermally-inverted atmosphere and shows no significant broadband water absorption feature. Detection of an anomalously strong super-Rayleigh slope in its optical transmission spectrum prompted follow-up transmission spectroscopy of WASP-103bs atmosphere using the MINiature Radial Velocity Array (MINERVA), which tentatively verified the unexplained super-Rayleigh spectral slope.The final follow-up technique for transiting planets presented in this work quantifies the information contained in a sequence of transit depths using a normalized information content metric. The normalized information content metric can distinguish between naturally occurring, regular transits of real exoplanets detected via Kepler (low information content) and simulated artificial beacons whose depth and timing vary in a prime number sequence (high information content). Highly variable transit sequences with natural explanationsas seen with KIC 12557548, for examplecan only be distinguished from artificial beacons when observed at a high signal-to-noise ratio (moderate information content) and may otherwise be confused with a more information-rich sequence.This dissertation also presents a review of effective methods for communicating science to various audiences, with specific applications to astronomy. That chapter highlights the necessity of integrating formal communications training into the early stages of a career in astronomy, explains why and how to apply storytelling techniques to astronomy communication, and details specific strategies to apply when using common communication media. Examples are given for effectively communicating astronomy through academic research papers, slides for an oral presentation, and academic research posters, as well as examples of popular science blogs, feature articles, and news stories.
