PH1b
| Discovery | |
|---|---|
| Discovered by | Planet Hunters |
| Discovery site | Kepler space telescope |
| Discovery date | 15 October 2012 |
| Transit | |
| Orbital characteristics | |
| 0.634 ± 0.011 AU | |
| 138.506+0.107 −0.092 d | |
| Semi-amplitude | (20.69±0.31)×103 |
| Star | Kepler-64 / PH1 |
| Physical characteristics | |
| 6.18±0.17 R🜨 | |
| Mass | 0.08–0.14 MJ (20–50 M🜨) |
| Temperature | 481 K (208 °C; 406 °F) |
PH1b (standing for "Planet Hunters 1"), or by its NASA designation Kepler-64b, is an extrasolar planet found in a circumbinary orbit in the quadruple star system Kepler-64. The planet was discovered by two amateur astronomers from the Planet Hunters project of amateur astronomers using data from the Kepler space telescope with assistance of a Yale University team of international astronomers. The discovery was announced on 15 October 2012. It is the first known transiting planet in a quadruple star system, first known circumbinary planet in a quadruple star system, and the first planet in a quadruple star system found. It was the first confirmed planet discovered by PlanetHunters.org. An independent and nearly simultaneous detection was also reported from a revision of Kepler space telescope data using a transit detection algorithm.