Gamma Cephei Ab
Artist impression of Tadmor, its host and the faint Gamma Cephei B. | |
| Discovery | |
|---|---|
| Discovered by | Bruce Campbell, Gordon Walker, Stephenson Yang, Hatzes et al. |
| Discovery site | United States |
| Discovery date | 13 July 1988 (suspected) 7 May 2003 (confirmed) |
| Doppler spectroscopy | |
| Orbital characteristics | |
| 2.05±0.06 AU | |
| Eccentricity | 0.049±0.034 |
| 903.3±1.5 d | |
| 2,453,227±87 | |
| 94.6±34.6 | |
| Semi-amplitude | 27.5 ± 1.5 |
| Star | γ Cephei A |
| Physical characteristics | |
| Mass | 9.4+0.7 −1.1 MJ |
Gamma Cephei Ab (abbreviated γ Cephei Ab, γ Cep Ab), formally named Tadmor /ˈtædmɔːr/, is an exoplanet approximately 45 light-years away in the constellation of Cepheus that orbits Gamma Cephei A. The planet was suspected to exist in 1988, and later confirmed in 2003, technically making it the first exoplanet discovered.