KOI-256 is a double star located in the constellation Cygnus approximately 575 light-years (176 pc) from Earth.

Initial observations by the Kepler spacecraft suggested a central red dwarf with a mass of 0.65 M☉, a radius of 1.1 R☉, and a temperature of 3,639 K (3,366 °C; 6,091 °F).

Its candidate exoplanet was estimated to have a mass of 14.8 ME, a radius of 25.34 R🜨, an orbital period of 1.38 days, a temperature of 1,160 K (890 °C; 1,630 °F), and a semi-major axis of 0.021 astronomical units.

[6][7] Further studies by Muirhead et al. (2012) refined the candidate exoplanet parameters to a radius of 5.60±0.76  R🜨, a temperature of 726 K (453 °C; 847 °F), and a semi-major axis of 0.016 AU.

[8] Muirhead et al. (2013) performed additional observations with the Hale Telescope at Palomar Observatory.