V391 Pegasi b
| Extrasolar planet | List of extrasolar planets | |
|---|---|---|
 | ||
| Parent star | ||
| Star | V391 Pegasi | |
| Constellation | Pegasus | |
| Right ascension | (α) | 22h 04m 12.2s |
| Declination | (δ) | +26° 25′ 08″ |
| Distance | 4570 ly (1400 pc) | |
| Spectral type | sdB | |
| Orbital elements | ||
| Semimajor axis | (a) | 1.7±0.1 AU |
| Eccentricity | (e) | 0 |
| Orbital period | (P) | 1170±44 d |
| Argument of periastron |
(ω) | 23.5±7.0° |
| Time of periastron | (T0) | 2,452,418±96 JD |
| Semi-amplitude | (K) | 76.7 m/s |
| Physical characteristics | ||
| Minimum mass | (m sin i) | 3.2±0.7 MJ |
| Discovery information | ||
| Discovery date | Mar-Sept 2007 | |
| Discoverer(s) | Silvotti et al. | |
| Discovery method | variable star timing | |
| Discovery status | Published | |
| Other designations | ||
| HS 2201+2610 b
| ||
V391 Pegasi b, also known as HS 2201+2610 b, is an extrasolar planet orbiting the star V391 Pegasi approximately 4570 light-years away in the constellation of Pegasus. The planet was discovered by means of variable star timing, which measured anomalies in variability of the star caused by a planet. It is the first planet to be detected with this method. It found to have mass of 3.2 times Jupiter, semi-major axis of 1.7 AU, and orbital period of 1170 days. The planet was discovered in March 2007 and published in September 2007. Its survival indicates that planets at Earth-like distances can survive their star's red-giant phase, though this is a much larger planet than Earth (about the same size as Jupiter and Saturn).[1]
References
- R. Silvotti; S. Schuh; R. Janulis; S. Bernabei; R. Ostensen; J.-E. Solheim; I. Bruni; R. Gualandi; T. Oswalt; A. Bonanno; B. Mignemi; the Whole Earth Telescope Xcov23 collaboration (2007). "The O-C diagram of the subdwarf B pulsating star HS2201+2610: detection of a giant planet?". ASP conf. series. arXiv:astro-ph/0703753. Bibcode:2007ASPC..372..369S.
- R. Silvotti; S. Schuh; R. Janulis; J.-E. Solheim; S. Bernabei; R. Østensen; T. D. Oswalt; I. Bruni; R. Gualandi; A. Bonanno; G. Vauclair; M. Reed; C.-W. Chen; E. Leibowitz; M. Paparo; A. Baran; S. Charpinet; N. Dolez; S. Kawaler; D. Kurtz; P. Moskalik; R. Riddle & S. Zola (2007). "A giant planet orbiting the 'extreme horizontal branch' star V 391 Pegasi". Nature 449 (7159): 189–191. Bibcode:2007Natur.449..189S. doi:10.1038/nature06143. PMID 17851517. Retrieved 2007-09-15.
External links
Coordinates: 
22h 04m 12.2s, +26° 25′ 08″