KOI-1257 is 2,140 light-years from the Sun. The NASA Exoplanet Archive lists 1 planet around this G5 V star; the first was found in 2014 by transit (Kepler).
Fly there in 3DKOI-1257 b goes round its star every 86.6 days, 1.0 times as often as Mercury goes round the Sun.
KOI-1257 is one of 2 stars in its system. The position of the other star is not catalogued, so only KOI-1257 and its planets are drawn.
| Spectral type | G5 V |
| Surface temperature | 5,520 K |
| Mass | 0.99 solar masses |
| Radius | 1.13 solar radii |
| Luminosity | 1.07 times the Sun |
| Apparent magnitude | 14.818 |
| Age | about 9.3 billion years |
| Distance from the Sun | 2139.6 light-years (656.0 parsecs) |
| Position (J2000) | RA 291.2251°, Dec 44.9273° |
| Constellation | Cygnus |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| KOI-1257 b | 86.6 days | 0.382 AU | 10.54 R⊕ | 460.83 M⊕ | Transit, 2014 |
Values are the NASA Exoplanet Archive’s composite parameters. A radius marked estimated comes from a mass–radius relation; a mass marked minimum is M sin i. Planet sizes and colours in the 3D view are renderings: none of these worlds has been photographed as more than a point of light.