HD 194688
K-type star in the constellation Delphinus
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HD 194688, also designated as HR 7816, is a solitary star located in the northern constellation Delphinus, the dolphin. It has an apparent magnitude of 6.22,[3] placing it near the limit for naked eye visibility. The object is located relatively far away at a distance of 886 light-years based on Gaia DR3 parallax measurements,[2] but it is drifting closer with a heliocentric radial velocity of −17.12 km/s.[6] At its current distance, HD 196488's brightness is diminished due to an interstellar extinction of 0.17 magnitudes[11] and it has an absolute visual magnitude of −1.19.[1]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Delphinus[1] |
| Right ascension | 20h 26m 23.15478s[2] |
| Declination | +17° 18′ 56.0140″[2] |
| Apparent magnitude (V) | 6.22±0.01[3] |
| Characteristics | |
| Evolutionary stage | red giant branch[2] |
| Spectral type | K0III[4] |
| B−V color index | +1.01[5] |
| Astrometry | |
| Radial velocity (Rv) | −17.12±0.27[6] km/s |
| Proper motion (μ) | RA: +5.397 mas/yr[2] Dec.: −5.426 mas/yr[2] |
| Parallax (π) | 3.6827±0.0184 mas[2] |
| Distance | 886 ± 4 ly (272 ± 1 pc) |
| Absolute magnitude (MV) | −1.19[1] |
| Details | |
| Mass | 1.57[7] M☉ |
| Radius | 21.58[8] R☉ |
| Luminosity | 258+3 −2[2] L☉ |
| Surface gravity (log g) | 1.91[7] cgs |
| Temperature | 4,995±122[9] K |
| Metallicity [Fe/H] | −0.13[7] dex |
| Other designations | |
| AG+17°2201, BD+16°4259, FK5 3635, GC 28435, HD 194688, HIP 100807, HR 7816, SAO 106101, TIC 305526917[10] | |
| Database references | |
| SIMBAD | data |
HD 194688 has a simple stellar classification of K0III,[4] indicating that it is an early K-type star. It has 1.57 times the mass of the Sun[7] and an enlarged radius 21.58 times that of the Sun.[8] It radiates 258 times the luminosity of the Sun[2] from its photosphere at an effective temperature of 4,995 K,[9] giving it an orangish-yellow hue when viewed in the night sky. The large radius and high luminosity suggests that HD 194688 may be an evolved giant star. It is slightly metal-deficient with an iron abundance 74.1% that of the Sun's.[7]