HD 190422
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  | |
| 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] |
| Distance | 78.58 ± 0.05 ly (24.09 ± 0.02 pc) |
| Absolute magnitude (MV) | +4.41[6] |
| Details | |
| Mass | 1.25[7] M☉ |
| Radius | 1.09±0.05[8] R☉ |
| Luminosity | 1.534+0.006 −0.005[1] L☉ |
| Surface gravity (log g) | 4.42[3] cgs |
| Temperature | 6,235±100[9] K |
| Metallicity [Fe/H] | −0.13±0.03[10] dex |
| Rotation | 27.2 d[11] |
| Rotational velocity (v sin i) | 15.6±0.8[12] km/s |
| Age | 400[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 | |
| SIMBAD | data |
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.
