HD 190422

HD 190422
Location of HD 190422(circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Telescopium
Right ascension 20h 07m 35.09061s[1]
Declination −55° 00′ 57.6492″[1]
Apparent magnitude (V) 6.25±0.01[2]
Characteristics
Spectral type F9 V CH−0.4[3]
B−V color index +0.53[4]
Astrometry
Radial velocity (Rv)12.7±0.3[5] km/s
Proper motion (μ) RA: +18.283 mas/yr[1]
Dec.: +35.310 mas/yr[1]
Parallax (π)41.5069 ± 0.028 mas[1]
Distance78.58 ± 0.05 ly
(24.09 ± 0.02 pc)
Absolute magnitude (MV)+4.41[6]
Details
Mass1.25[7] M☉
Radius1.09±0.05[8] R☉
Luminosity1.534+0.006
−0.005[1] L☉
Surface gravity (log g)4.42[3] cgs
Temperature6,235±100[9] K
Metallicity [Fe/H]−0.13±0.03[10] dex
Rotation27.2 d[11]
Rotational velocity (v sin i)15.6±0.8[12] km/s
Age400[13][3] Myr
Other designations
77 G. Telescopii[14], CD−55°8393, CPD−55°9317, GC 27884, HD 190422, HIP 99137, HR 7674, SAO 246444[15]
Database references
SIMBADdata

HD 190422, also known as HR 7674 or rarely 77 G. Telescopii, is a solitary star located in the southern constellation Telescopium. It has an apparent magnitude of +6.25,[2] placing it near the limit for naked eye, even under ideal conditions. At its current distance, HD 190422's brightness is diminished by 0.11 magnitudes due to extinction from interstellar dust[16] and it has an absolute magnitude of +4.41.[6]

The star is located relatively close at a distance of 79 light years based on Gaia DR3 parallax measurements[1] but it is receding with a heliocentric radial velocity of 12.7 km/s.[5] Approximately 1.6 million years ago, HD 190422 was located 7.806 parsecs (25.46 ly) away from the Sun.[17]

HD 190422 has a stellar classification of F9 V CH−0.4,[3] indicating that it is a F-type main-sequence star with a mild underabundance of the CH radical in its spectrum. It has 125% the mass of the Sun[7] and 109% of the Sun's radius.[8] It radiates 1.534 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 6,235 K,[9] giving it a whitish-yellow hue. HD 190422 is slightly metal deficient with a metallicity of [Fe/H] = −0.13[10] and it spins modestly with a projected rotational velocity of 15.6 km/s.[12] The star is estimated to be 400 million years old,[13][3] less than a tenth the age of the Sun.

  1. ^ a b c d e f g Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gontcharov2006 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 Cite error: The named reference Chanlder2016 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Kervella2004 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Casagrande2011 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Netopil2017 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference oelkers2018 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference Ammler-von Eiff2012 was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference Henry1996 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Bailer-Jones2015 was invoked but never defined (see the help page).