CAMBRIDGE, Mass. — Astronomers have spotted a new kind of planet: a Neptune-sized world sitting scorchingly close to its star. It could be in the midst of transforming from a hot, puffy gas giant to a naked rocky core, astronomer James Jenkins reported July 29 at the TESS Science Conference at MIT.
“This planet is amazing. It’s the first of its kind,” says astronomer Elisabeth Adams of the Planetary Science Institute, who is based in Somerville, Mass. Adams studies larger planets that orbit close to their stars, but wasn’t involved in the discovery.
The planet, called LTT 9779b, orbits a sunlike star about 260 light-years away. It was discovered by NASA’s Transiting Exoplanet Survey Satellite, or TESS, which launched in April 2018 (SN: 5/12/18, p. 7). Data collected by TESS show that the planet swings around its star once every 19 hours, putting it in a rare class of planets that orbit incredibly close to their stars.