51 Pegasi b
| Exoplanet | List of exoplanets | |
|---|---|---|
 |
||
| Parent star | ||
| Star | 51 Pegasi | |
| Constellation | Pegasus | |
| Right ascension | (α) | 22h 57m 28.0s |
| Declination | (δ) | +20° 46′ 08″ |
| Apparent magnitude | (mV) | 5.49 |
| Distance | 50.9 ± 0.3 ly (15.61 ± 0.09 pc) |
|
| Spectral type | G2.5IVa or G4-5Va | |
| Mass | (m) | 1.06 M☉ |
| Radius | (r) | 1.237 ± 0.047 R☉ |
| Temperature | (T) | 5571 ± 102 K |
| Metallicity | [Fe/H] | 0.20 ± 0.07 |
| Age | 6.1-8.1 Gyr | |
| Orbital elements | ||
| Semi-major axis | (a) | 0.0527 ± 0.0030 AU (7.89 Gm) |
| Periastron | (q) | 0.0520 AU (7.79 Gm) |
| Apastron | (Q) | 0.0534 AU (7.99 Gm) |
| Eccentricity | (e) | 0.013 ± 0.012 |
| Orbital period | (P) | 4.230785 ± 0.000036 d |
| (101.5388 h) | ||
| Orbital speed | (υ) | 136 km/s |
| Argument of periastron |
(ω) | 58° |
| Time of periastron | (T0) | 2,450,001.51 ± 0.61 JD |
| Semi-amplitude | (K) | 55.94 ± 0.69 m/s |
| Physical characteristics | ||
| Minimum mass | (m sin i) | 0.472 ± 0.039 MJ |
| Stellar flux | (F⊙) | 480 ⊕ |
| Rotation period | (ω) | Synchronous |
| Temperature | (T) | 1284 ± 19 |
| Discovery information | ||
| Discovery date | 6 October 1995 | |
| Discoverer(s) |
Michel Mayor and Didier Queloz |
|
| Discovery method | Radial velocity (ELODIE) | |
| Discovery site | OHP, France | |
| Discovery status | Published | |
| Other designations | ||
|
Dimidium, Bellerophon
|
||
| Database references | ||
| Extrasolar Planets Encyclopaedia |
data | |
| SIMBAD | data | |
| Exoplanet Archive | data | |
| Open Exoplanet Catalogue | data | |
51 Pegasi b (abbreviated 51 Peg b), unofficially dubbed Bellerophon, later named Dimidium, is an extrasolar planet approximately 50 light-years away in the constellation of Pegasus. It was the first exoplanet to be discovered orbiting a main-sequence star, the Sun-like 51 Pegasi, and marked a breakthrough in astronomical research. It is the prototype for a class of planets called hot Jupiters.
51 Pegasi is the Flamsteed designation of the host star. The planet was originally designated 51 Pegasi b by Michel Mayor and Didier Queloz, who discovered the planet. The following year it was unofficially dubbed Bellerophon by astronomer Geoffrey Marcy, who followed the convention of naming planets after Greek and Roman mythological figures (Bellerophon was a figure from Greek mythology who rode the winged horse Pegasus).
In July 2014, the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars. The process involved public nomination and voting for the new names. In December 2015, the IAU announced the winning name for this planet was Dimidium. The name was submitted by the Astronomische Gesellschaft Luzern (German for Astronomical Society of Lucerne), Switzerland. 'Dimidium' is Latin for 'half', referring to the planet's mass of at least half the mass of Jupiter.
...
Wikipedia