SDSU Astronomers Discover Two New 'Tatooine' Planetary Systems

Astronomers announced the first discovery made by NASA's TESS Mission of a two-star planetary system. Led by researchers at NASA's Goddard Space Flight Center and San Diego State University, with other collaborators, this finding marks the start of a much better understanding of the population of such planetary systems.

On behalf of the international team of 60 investigators the work was presented by researcher Veselin Kostov at the 235th meeting of the American Astronomical Society in Honolulu.

The new planet, called “TOI-1338 b”, is roughly 6.9 times larger than the Earth. It orbits its pair of host stars every 95 days. One of the stars is more massive and much brighter than the other, and as the planet orbits around it blocks some of the light from the brighter star. This “transit” allows astronomers to measure the size of the planet. The transit was first found in the TESS data by a high-school student working at NASA over the summer with Kostov.

A dozen such Tatooine-like planets were found with NASA's Kepler Mission, which ended in 2013. The TESS telescope, launched in 2018, will cover nearly the whole sky and enable many more discoveries, perhaps as many as 100 new circumbinary planets. A sample size that large will allow a statistical analysis of the population, which to date has not been possible because too few systems are known.

Video provided by: NASA