HD 200779

HD 200779
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Equuleus
Right ascension 21h 05m 19.74605s[1]
Declination +07° 04′ 09.4729″[1]
Apparent magnitude (V) 8.27[2]
Characteristics
Spectral type K6 V[3]
U−B color index +1.12[4]
B−V color index +1.21[4]
R−I color index +0.61[2]
Astrometry
Radial velocity (Rv)−66.94±0.18[5] km/s
Proper motion (μ) RA: +78.562 mas/yr[1]
Dec.: −563.909 mas/yr[1]
Parallax (π)66.4626 ± 0.0225 mas[1]
Distance49.07 ± 0.02 ly
(15.046 ± 0.005 pc)
Absolute magnitude (MV)+7.38[6]
Details
Mass0.68±0.01[7] M☉
Radius0.689+0.077
−0.050[8] R☉
Luminosity0.18[9] L☉
Surface gravity (log g)4.67±0.02[7] cgs
Temperature4,406±73[10] K
Metallicity [Fe/H]+0.05±0.06[7] dex
Rotational velocity (v sin i)5.1±1.2[5] km/s
Age6.33[11] Gyr
Other designations
AG+06°2882, BD+06°4741, GC 29447, GJ 818, HD 200779, HIP 104092, SAO 126533, CCDM J21054+0704A, WDS J21053+0704A, LFT 160, LHS 3624, LTT 16169[12]
Database references
SIMBADdata
ARICNSdata

HD 200779 (HIP 104092; Gliese 818; LHS 3624) is a solitary star located in the equatorial constellation Equuleus, the foal. It has an apparent magnitude of 8.27,[2] making it readily visible in binoculars but not to the naked eye. The object is located relatively close at a distance of 49 light years based on Gaia DR3 parallax measurements,[1] which makes it the nearest star in Equuleus.[13] It is classified as a high proper motion star,[12] with a total proper motion of 569 mas/yr.[1]

At its current distance, HD 200779's brightness is diminished by only six hundredths of a magnitude due to interstellar dust[14] and it has an absolute magnitude of +7.38.[6] HD 200779 is expected to come within 7.76 parsecs (25.3 ly) of the Solar System in roughly 160,000 years.[15]

HD 200779 is an ordinary K-type main-sequence star with a stellar classification of K6 V.[3] It has 68% the mass of the Sun[7] and 69% of its radius.[8] However, it only radiates 18% the luminosity of the Sun[9] from its photosphere at an effective temperature of 4,406 K,[10] giving it an orange hue. It has an iron abundance slightly above solar level at [Fe/H] = +0.05[7] and it is estimated to be 6.33 billion years old.[11] HD 200779 spins modestly with a projected rotational velocity of 5.1 km/s.[5] The star is generally considered to be chromospherically active.[3]

HD 200779 has two optical companions: a distant 11th magnitude star located 64.6" away and a 9th magnitude star located 169.4" away.[16]

  1. ^ a b c d e f Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Koen2010 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Gray2003 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Roman1955 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Tokovinin1992 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference Ramírez2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Luck2018 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Dotter2008 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  13. ^ Kirkpatrick, J. Davy; Marocco, Federico; Gelino, Christopher R.; Raghu, Yadukrishna; Faherty, Jacqueline K.; Bardalez Gagliuffi, Daniella C.; Schurr, Steven D.; Apps, Kevin; Schneider, Adam C.; Meisner, Aaron M.; Kuchner, Marc J.; Caselden, Dan; Smart, R. L.; Casewell, S. L.; Raddi, Roberto (2024-04-01). "The Initial Mass Function Based on the Full-sky 20 pc Census of ∼3600 Stars and Brown Dwarfs". The Astrophysical Journal Supplement Series. 271 (2): 55. arXiv:2312.03639. Bibcode:2024ApJS..271...55K. doi:10.3847/1538-4365/ad24e2. ISSN 0067-0049.
  14. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Bailer-Jones2015 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Mason2001 was invoked but never defined (see the help page).