HR 8799

HR 8799

HR 8799 (center) with HR 8799 e (right), HR 8799 d (lower right), HR 8799 c (upper right), HR 8799 b (upper left) from W. M. Keck Observatory
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pegasus
Right ascension 23h 07m 28.7157s[1]
Declination +21° 08′ 03.311″[1]
Apparent magnitude (V) 5.964[2]
Characteristics
Spectral type kA5 hF0 mA5 V; λ Boo[3][4]
U−B color index −0.04[5]
B−V color index 0.234[2]
Variable type Gamma Doradus variable[2]
Astrometry
Radial velocity (Rv)−11.5±2[2] km/s
Proper motion (μ) RA: 108.284±0.056[1] mas/yr
Dec.: −50.040±0.059[1] mas/yr
Parallax (π)24.4620 ± 0.0455 mas[1]
Distance133.3 ± 0.2 ly
(40.88 ± 0.08 pc)
Absolute magnitude (MV)2.98±0.08[3]
Details
Mass1.43+0.06
−0.07[6] M☉
Radius1.34±0.05[3] R☉
Luminosity (bolometric)4.92±0.41[3] L☉
Surface gravity (log g)4.35±0.05[3] cgs
Temperature7430±75[3] K
Metallicity [Fe/H]−0.52±0.08[7][a] dex
Rotational velocity (v sin i)37.5±2[3] km/s
Age30+20
−10[8] Myr
Other designations
V342 Pegasi, BD+20 5278, FK5 3850, GC 32209, HD 218396, HIP 114189, PPM 115157, SAO 91022, TYC 1718-2350-1.[2]
Database references
SIMBADdata
Exoplanet Archivedata

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).

  1. ^ a b c d e Cite error: The named reference Gaia-EDR3 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference simbad-HR8799 was invoked but never defined (see the help page).
  3. ^ a b c d e f g Cite error: The named reference Gray-Kaye-1999 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Kaye-Handler-etal-1999 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Yale-BSC-1991-06 was invoked but never defined (see the help page).
  6. ^ Sepulveda, Aldo G.; Bowler, Brendan P. (2022). "Dynamical Mass of the Exoplanet Host Star HR 8799". The Astronomical Journal. 163 (2): 52. arXiv:2111.12090. Bibcode:2022AJ....163...52S. doi:10.3847/1538-3881/ac3bb5. S2CID 232572566.
  7. ^ Cite error: The named reference Wang-Wang-etal-2020 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Marois-etal-2011 was invoked but never defined (see the help page).


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