In hunt for life, astronomers identify most promising stars

European Space Agency, European Southern Observatory and NASA’s Goddard Space Flight Center/Provided Artists’ concept of the Transiting Exoplanet Survey Satellite against a background of stars and orbiting planets in the Milky Way

ITHACA, N.Y. – NASA’s new Transiting Exoplanet Survey Satellite (TESS) is designed to ferret out habitable exoplanets, but with hundreds of thousands of sunlike and smaller stars in its camera views, which of those stars could host planets like our own?

A team of astronomers from Cornell, Lehigh University and Vanderbilt University has identified the most promising targets for this search in the new “TESS Habitable Zone Star Catalog,” published March 26 in Astrophysical Journal Letters. Lead author Lisa Kaltenegger, professor of astronomy in the College of Arts and Sciences and director of Cornell’s Carl Sagan Institute, is a member of the TESS science team. 

The catalog identifies 1,822 stars for which TESS is sensitive enough to spot Earth-like planets just a bit larger than Earth that receive radiation from their star equivalent to what Earth receives from our sun. For 408 stars, TESS can glimpse a planet just as small as Earth, with similar irradiation, in one transit alone.

“Life could exist on all sorts of worlds, but the kind we know can support life is our own, so it makes sense to first look for Earth-like planets,” Kaltenegger said. “This catalog tells us around which stars we can find the closest Earth-analogs with TESS.” “I now have 408 new favorite stars,” said Kaltenegger. “And if you have good binoculars, you can see some of them from your backyard on a dark night.”

Kaltenegger leads a program on TESS that is observing the catalog’s 1,822 stars in detail, looking for planets. the catalog is available online as is the TESS data. “I hope a lot of people are going to use this catalog to make sure we’ll find all the Earth-like planets with TESS – and also all the other planets in those systems – so we can fully see the diversity of planetary systems and how ours fits in.”

In addition to Kaltenegger, Joshua Pepper of Lehigh University and Keivan Stassun and Ryan Oelkers of Vanderbilt University contributed to the catalog, which draws from one originally developed at Vanderbilt that contains hundreds of millions of stars.

“This is a remarkable time in human history and a huge leap for our understanding of our place in the universe,” said Stassun, a member of the TESS science team.

by Linda Glaeser and Lisa Kaltenegger
For additional information, see this Cornell Chronicle story