The Transiting Exoplanet Survey Satellite (1406.0151v3)

Abstract: The Transiting Exoplanet Survey Satellite (TESS) will search for planets transiting bright and nearby stars. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission. The spacecraft will be placed into a highly elliptical 13.7-day orbit around the Earth. During its two-year mission, TESS will employ four wide-field optical CCD cameras to monitor at least 200,000 main-sequence dwarf stars with I = 4-13 for temporary drops in brightness caused by planetary transits. Each star will be observed for an interval ranging from one month to one year, depending mainly on the star's ecliptic latitude. The longest observing intervals will be for stars near the ecliptic poles, which are the optimal locations for follow-up observations with the James Webb Space Telescope. Brightness measurements of preselected target stars will be recorded every 2 min, and full frame images will be recorded every 30 min. TESS stars will be 10-100 times brighter than those surveyed by the pioneering Kepler mission. This will make TESS planets easier to characterize with follow-up observations. TESS is expected to find more than a thousand planets smaller than Neptune, including dozens that are comparable in size to the Earth. Public data releases will occur every four months, inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the nearest and brightest stars hosting transiting planets, which will endure as highly favorable targets for detailed investigations.

• The paper demonstrates TESS’s mission to discover transiting exoplanets, focusing on planets smaller than Neptune by surveying over 200,000 main-sequence dwarf stars.
• It outlines the use of four wide-field CCD cameras that capture full-frame images every 30 minutes, enabling precise transit detection across a 2300 square degree field.
• TESS’s results are expected to advance exoplanet characterization and stellar studies, paving the way for detailed follow-up observations with instruments like JWST.

The Transiting Exoplanet Survey Satellite: An Overview

The Transiting Exoplanet Survey Satellite (TESS) represents a significant endeavor in the field of exoplanet research, initiated as part of NASA's Astrophysics Explorer Missions. This mission is poised to expand our understanding of exoplanets by identifying and characterizing planets that transit bright and nearby stars. Scheduled for launch with the aim of surveying over 200,000 main-sequence dwarf stars, TESS is expected to facilitate breakthroughs in the characterization of thousands of new exoplanets.

Mission Objectives and Design

TESS's primary objectives focus on the discovery of transiting exoplanets that are smaller than Neptune, with host stars bright enough to permit comprehensive follow-up spectroscopy. The mission uniquely positions itself following NASA's Kepler mission by targeting the nearest and brightest stars across the entire sky, thus addressing the limitation faced by Kepler which observed fainter stars. The design capitalizes on a two-year extensive sky survey using four wide-field optical CCD cameras to capture variations in star brightness that suggest planetary transits.

Operational Strategy and Technological Implementation

Located in a 13.7-day highly elliptical orbit, TESS will employ a robust data collection strategy, taking full frame images every 30 minutes and recording brightness measurements for targeted stars every 2 minutes. The choice of its orbit offers several operational advantages, including reduced radiation exposure and stable thermal conditions, while the cadence of data collection facilitates the precise detection of transiting planets.

Each of the four cameras features a sophisticated design with a 24° by 24° field of view, and when combined, they cover approximately 2300 square degrees on the sky. The advanced CCDs used promise excellent photometric precision, leveraging 600-1000 nm bandpass sensitivity to optimize the detection of planetary transits, especially around cooler stars such as M dwarfs.

Anticipated Discoveries and Scientific Contributions

TESS is anticipated to identify thousands of exoplanets, including super-Earths and Earth-sized planets, potentially in habitable zones around M-type stars. This array of discoveries is expected to result from a meticulous simulation of stellar and planetary properties, relying on an enhanced understanding of the local stellar population as informed by the Kepler mission findings.

The high cadence observations will further allow contributions to astrophysical fields beyond exoplanet detection, including time-domain astronomy and asteroseismology. TESS is equipped to detect pulsations in thousands of stars, enabling detailed studies of stellar structures.

Conclusion and Future Implications

The TESS mission is anticipated to create a foundational catalog of exoplanets orbiting the nearest bright stars, paving the way for subsequent investigations with instruments such as the future James Webb Space Telescope (JWST). By widening the scope of stellar targets and demonstrating improved detection capabilities, TESS will not only enhance the exoplanetary targets available for current technological capabilities but will also inform the development of future missions designed to explore these newfound exoplanets in greater detail.

Overall, TESS holds potential as a transformative mission, serving as an impetus for expansive community-driven scientific inquiry into extrasolar worlds. Its data, released in a timely manner, will engage the scientific community at multiple levels, enriching our collective understanding of the cosmos.