HD 187923
Star in the constellation Aquila
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HD 187923 is a suspected variable star[6] 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.[3] Based upon an annual parallax shift of 37.03 mas,[2] 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.[3] It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.480″ per year.[10]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila[1] |
| Right ascension | 19h 52m 03.43838s[2] |
| Declination | +11° 37′ 41.9723″[2] |
| Apparent magnitude (V) | 6.148[3] |
| Characteristics | |
| Evolutionary stage | subgiant[2] |
| Spectral type | G0 V[4] |
| U−B color index | +0.12[5] |
| B−V color index | +0.65[5] |
| Variable type | suspected[6] |
| Astrometry | |
| Radial velocity (Rv) | −20.7±0.2[3] km/s |
| Proper motion (μ) | RA: −344.042[2] mas/yr Dec.: −334.600[2] mas/yr |
| Parallax (π) | 37.0027±0.0269 mas[2] |
| Distance | 88.14 ± 0.06 ly (27.03 ± 0.02 pc) |
| Absolute magnitude (MV) | 3.94[3] |
| Details[7] | |
| Mass | 1.28±0.17 or 1.02[8] M☉ |
| Radius | 1.44±0.04 R☉ |
| Luminosity | 2.09+0.10 −0.09 L☉ |
| Surface gravity (log g) | 4.23 cgs |
| Temperature | 5,774 K |
| Metallicity [Fe/H] | −0.11 dex |
| Rotational velocity (v sin i) | 0.1 km/s |
| Age | 8.8±0.7 or 10.2[8] Gyr |
| Other designations | |
| NSV 12490, BD+11°4019, GJ 4126, HD 187923, HIP 97767, HR 7569, SAO 105348, WDS J19521+1138A, LTT 15805[9] | |
| Database references | |
| SIMBAD | data |
This is an ordinary G-type main-sequence star with a stellar classification of G0 V.[4] It has some similarities to the Sun, and thus is considered a solar analog.[11] 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.[7] 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.[8]