TESS - Astrophysics

What is TESS?

The Transiting Exoplanet Survey Satellite (TESS) is a space telescope launched by NASA with the primary mission of discovering exoplanets orbiting the brightest stars in the night sky. Launched in April 2018, TESS uses the transit photometry method to detect planets by observing the small dips in brightness that occur when a planet passes in front of its host star.

How does TESS work?

TESS is equipped with four wide-field cameras that allow it to monitor large sections of the sky for transiting exoplanets. Each camera has a 24° by 24° field of view, and together they cover a 96° by 24° strip of the sky. TESS observes one strip for about 27 days before rotating to the next, covering nearly the entire sky over its two-year primary mission. The data collected is then analyzed to identify periodic dips in star brightness which could indicate the presence of an exoplanet.

What are the key objectives of TESS?

The main objectives of TESS are to:

Discover thousands of exoplanets in orbit around the brightest stars near Earth.
Identify planets ranging from Earth-sized to larger gas giants.
Conduct detailed studies of the discovered planets’ masses, sizes, densities, and orbits.
Provide prime targets for follow-up observations by future missions, such as the James Webb Space Telescope.

What are some of TESS's notable discoveries?

Since its launch, TESS has made several significant discoveries, including:

TOI-700 d: An Earth-sized planet located in the habitable zone of its star.
TOI-849 b: A "super-Earth" that challenges current planetary formation theories.
LHS 3844 b: A rocky planet with no significant atmosphere, providing insights into planetary atmospheres.

How has TESS improved our understanding of exoplanets?

TESS has expanded our knowledge of exoplanets by:

Providing a large sample of nearby stars with discovered exoplanets, which are ideal for follow-up studies.
Finding a diverse range of exoplanets, from small rocky worlds to large gas giants, helping to refine models of planetary formation.
Offering insights into planetary atmospheres and compositions through detailed observations.

What is the future of TESS?

After completing its primary mission in 2020, TESS has entered an extended mission phase, continuing to survey the sky and discover new exoplanets. The data from TESS will continue to be invaluable for astronomers and will complement observations from other missions. TESS's discoveries will also help pave the way for future missions dedicated to studying exoplanet atmospheres and searching for signs of habitability and life beyond Earth.