Q2634622

Kepler-33 is a star about in the constellation of Cygnus, with a system of five known planets. Having just begun to evolve off from the main sequence, its radius and mass are difficult to ascertain, although data available in 2020 shows its best-fit mass of 1.3 and radius of 1.6 are compatible with a model of a subgiant star.

==Planetary system== The first detections of the candidate four-body planetary system were reported in February 2011. On January 26, 2012, the planetary system around the star was confirmed, including a fifth planet. However, unlike some other planets confirmed via Kepler, their masses were initially not known, as Doppler spectroscopy measurements were not done before the announcement. Judging by their radii, b may be a large super-Earth or small hot Neptune while the other four are all likely to be the latter. , the masses of planets e & f have been measured, with upper limits on the masses of planets c & d. These mass measurements confirm Kepler-33 d, e & f to be low-density, gaseous planets.