Kepler-283 c is a planet about 1.8 times Earth's width orbiting an orange dwarf star about 1,500 light-years away, at a distance where it receives about 95 percent of the light Earth gets from the Sun, according to the NASA Exoplanet Archive. It crosses in front of its star every 92.7 days and has an inner sibling, Kepler-283 b.
NASA's Kepler space telescope found both by the small dips in starlight they cause. They were confirmed in 2014 in a study led by Jason Rowe that validated hundreds of Kepler planets at once. That method relies on statistics: when a star shows more than one transit signal, it is very unlikely that all are false alarms from something else in view, so planets in such systems can be confirmed without measuring their masses.
Its starlight level placed it among the most Earth-like planets Kepler found. In 2016 a team led by David Armstrong studied the host stars of 15 of those planets, using the full Kepler record of each star's brightness, to look for things that could make a planet less habitable, such as flares and strong magnetic activity. For Kepler-283 they measured a rotation period of about 18 days, and estimated the star's activity and the size of the magnetic bubble a planet like Earth would need to shield its air. Kepler-283 c's mass has never been measured; the archive's figure of about 4 Earth masses is an estimate from its size. At about 1.8 Earth radii, it may be rocky or may have a thick atmosphere, and which is true is unknown.