HR 8799
HR 8799 (marked with star) with HR 8799 e (upper right), HR 8799 d (lower right), HR 8799 c (up from HR 8799 e) and HR 8799 b (left) from James Webb Space Telescope | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 23h 07m 28.7157s |
| Declination | +21° 08′ 03.311″ |
| Apparent magnitude (V) | 5.964 |
| Characteristics | |
| Spectral type | kA5 hF0 mA5 V; λ Boo |
| U−B color index | −0.04 |
| B−V color index | 0.234 |
| Variable type | Gamma Doradus variable |
| Astrometry | |
| Radial velocity (Rv) | −11.5±2 km/s |
| Proper motion (μ) | RA: 108.284±0.056 mas/yr Dec.: −50.040±0.059 mas/yr |
| Parallax (π) | 24.4620±0.0455 mas |
| Distance | 133.3 ± 0.2 ly (40.88 ± 0.08 pc) |
| Absolute magnitude (MV) | 2.98±0.08 |
| Details | |
| Mass | 1.43+0.06 −0.07 M☉ |
| Radius | 1.44±0.06 R☉ |
| Luminosity (bolometric) | 5.05±0.29 L☉ |
| Surface gravity (log g) | 4.35±0.05 cgs |
| Temperature | 7,193±87 K |
| Metallicity [Fe/H] | −0.52±0.08 dex |
| Rotational velocity (v sin i) | 37.5±2 km/s |
| Age | 42+24 −16 Myr |
| Other designations | |
| V342 Pegasi, BD+20 5278, FK5 3850, GC 32209, HD 218396, HIP 114189, PPM 115157, SAO 91022, TYC 1718-2350-1. | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
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HR 8799 is a roughly 30 million-year-old main-sequence star located 133.3 light-years (40.9 parsecs) away from Earth in the constellation of Pegasus. It has roughly 1.5 times the Sun's mass and 4.9 times its luminosity. It is part of a system that also contains a debris disk and at least four massive planets. These planets were the first exoplanets whose orbital motion was confirmed by direct imaging. The star is a Gamma Doradus variable: its luminosity changes because of non-radial pulsations of its surface. The star is also classified as a Lambda Boötis star, which means its surface layers are depleted in iron peak elements. It is the only known star which is simultaneously a Gamma Doradus variable, a Lambda Boötis type, and a Vega-like star (a star with excess infrared emission caused by a circumstellar disk).