HD 187923

HD 187923
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 19h 52m 03.43853s[1]
Declination +11° 37′ 41.9725″[1]
Apparent magnitude (V) 6.148[2]
Characteristics
Spectral type G0 V[3]
U−B color index +0.12[4]
B−V color index +0.65[4]
Variable type suspected[5]
Astrometry
Radial velocity (Rv)−20.7±0.2[2] km/s
Proper motion (μ) RA: −344.185[1] mas/yr
Dec.: -334.608[1] mas/yr
Parallax (π)37.0427 ± 0.0529 mas[1]
Distance88.0 ± 0.1 ly
(27.00 ± 0.04 pc)
Absolute magnitude (MV)3.94[2]
Details[6]
Mass1.28±0.17 or 1.02[7] M☉
Radius1.44±0.04 R☉
Luminosity2.09+0.10
−0.09 L☉
Surface gravity (log g)4.23 cgs
Temperature5,774 K
Metallicity [Fe/H]−0.11 dex
Rotational velocity (v sin i)0.1 km/s
Age8.8±0.7 or 10.2[7] Gyr
Other designations
NSV 12490, BD+11° 4019, GJ 4126, HD 187923, HIP 97767, HR 7569, SAO 105348, WDS J19521+1138A, LTT 15805[8]
Database references
SIMBADdata

HD 187923 is a suspected variable star[5] in the equatorial constellation of Aquila. It is a dim star that is just visible to the naked eye, having an apparent visual magnitude of 6.148.[2] Based upon an annual parallax shift of 37.04 mas,[1] it is located 88 light years away. The star is moving closer to the Earth with a heliocentric radial velocity of −20.7 km/s.[2] It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.480″ per year.[9]

This is an ordinary G-type main-sequence star with a stellar classification of G0 V.[3] It has some similarities to the Sun, and thus is considered a solar analog.[10] Brewer et al. (2016) estimate the star has 1.3 times the mass of the Sun and 1.44 times the Sun's radius. It is thought to be around 9 billion years old and is spinning slowly with a projected rotational velocity of 0.1 km/s. The star is radiating double the Sun's luminosity from its photosphere at an effective temperature of 5,774 K.[6] Casagrande et al. (2011) gave a much lower mass estimate of 1.02 times the Sun's mass with an age of around 10.2 billion years.[7]

  1. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Nordstrom2004 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference mnras396_4_1895 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference MERMILLIOD was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Brewer2016 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Casagrande2011 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Lepine2005 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Galeev2004 was invoked but never defined (see the help page).