Eta Pegasi
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 22h 43m 00.13743s |
| Declination | +30° 13′ 16.4822″ |
| Apparent magnitude (V) | +2.95 |
| Characteristics | |
| Spectral type | G2 II + F0 V |
| U−B color index | +0.57 |
| B−V color index | +0.86 |
| Astrometry | |
| Radial velocity (Rv) | +4.3 km/s |
| Proper motion (μ) | RA: +13.16 mas/yr Dec.: -25.67 mas/yr |
| Parallax (π) | 16.6308±0.7047 mas |
| Distance | 196 ± 8 ly (60 ± 3 pc) |
| Absolute magnitude (MV) | –1.18 |
| Orbit | |
| Period (P) | 813 days |
| Eccentricity (e) | 0.183 |
| Periastron epoch (T) | 2452025 HJD |
| Argument of periastron (ω) (secondary) | 344.7° |
| Semi-amplitude (K1) (primary) | 14.37 km/s |
| Details | |
| η Peg A | |
| Mass | 3.51±0.13 M☉ |
| Radius | 24.51+1.11 −1.21 R☉ |
| Luminosity | 330.8±35.0 L☉ |
| Surface gravity (log g) | 2.40 cgs |
| Temperature | 4970±65 K |
| Metallicity [Fe/H] | +0.39 dex |
| Rotation | 818 |
| Rotational velocity (v sin i) | 1.4 km/s |
| Age | 0.27±0.03 Gyr |
| Other designations | |
| Matar, Eta Peg, η Peg, 44 Peg, BD+29°4741, FK5 857, HD 215182, HIP 112158, HR 8650, SAO 90734 | |
| Database references | |
| SIMBAD | data |
Eta Pegasi or η Pegasi, formally named Matar /ˈmeɪtɑːr/, is a binary star in the constellation of Pegasus. The apparent visual magnitude of this star is +2.95, making it the fifth-brightest member of Pegasus. Based upon parallax measurements, the distance to this star is about 214 light-years (66 parsecs) from the Sun.