HD 193556
G-type star in the constellation Delphinus
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HD 193556 (HR 7778) is a solitary star in the equatorial constellation Delphinus. It has an apparent magnitude of 6.17,[3] making it visible to the naked eye under ideal conditions. Parallax measurements place the object at a distance of 467 light years[2] and it is currently receding with a heliocentric radial velocity of 11.7 km/s.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Delphinus[1] |
| Right ascension | 20h 20m 20.5234s[2] |
| Declination | +14° 34′ 09.321″[2] |
| Apparent magnitude (V) | 6.17±0.01[3] |
| Characteristics | |
| Spectral type | G8 III[4] |
| U−B color index | +0.67[5] |
| B−V color index | +0.92[5] |
| Astrometry | |
| Radial velocity (Rv) | 11.7±0.3[6] km/s |
| Proper motion (μ) | RA: −3.887 mas/yr[2] Dec.: +5.610 mas/yr[2] |
| Parallax (π) | 6.9878±0.0252 mas[2] |
| Distance | 467 ± 2 ly (143.1 ± 0.5 pc) |
| Absolute magnitude (MV) | +0.04[1] |
| Details | |
| Mass | 2.65[7] M☉ |
| Radius | 11.33[8] R☉ |
| Luminosity | 102[9] L☉ |
| Surface gravity (log g) | 2.76[10] cgs |
| Temperature | 5,104[10] K |
| Metallicity [Fe/H] | +0.03[10] dex |
| Rotational velocity (v sin i) | 1.5±1.2[11] km/s |
| Age | 490[7] Myr |
| Other designations | |
| AG+14°2187, BD+14°4263, FK5 3629, GC 28288, HD 193556, HIP 100274, HR 7778, SAO 105988[12] | |
| Database references | |
| SIMBAD | data |
HD 193556 has a stellar classification of G8 III,[4] indicating that it is a red giant. It has 2.65 times the mass of the Sun and is currently 490 million years old,[7] having expanded to 11.33 times the radius of the Sun.[8] It shines with a luminosity of 102 L☉[9] from its enlarged photosphere at an effective temperature of 5,104 K,[10] giving it a yellow glow. HD 193556 has an iron abundance around solar level[10] and spins leisurely with a poorly constrained projected rotational velocity of 1.5 km/s.[11]