| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Delphinus |
| Right ascension | 20h49m 59.0925s[1] |
| Declination | +05° 32′ 40.5081″[1] |
| Apparent magnitude (V) | 6.19±0.01[2] |
| Characteristics | |
| Spectral type | K0[3] |
| U−B color index | +0.79[4] |
| B−V color index | +0.98[4] |
| Astrometry | |
| Radial velocity (Rv) | −21.63±0.31[5] km/s |
| Proper motion (μ) | RA: +43.408 mas/yr[1] Dec.: −0.174 mas/yr[1] |
| Parallax (π) | 8.2537 ± 0.1261 mas[1] |
| Distance | 395 ± 6 ly (121 ± 2 pc) |
| Absolute magnitude (MV) | +0.7[6] |
| Details | |
| Mass | 3.12[7] M☉ |
| Radius | 10.54[8] R☉ |
| Luminosity | 56.3[9] L☉ |
| Surface gravity (log g) | 2.8[7] cgs |
| Temperature | 4,809[10] K |
| Metallicity [Fe/H] | +0.17[7] dex |
| Other designations | |
21 G. Delphini, AG+05°3046, BD+05°4626, GC 29044, HD 198404, HIP 102833, HR 7975, SAO 126267, WDS J20500+0533A[11][12] | |
| Database references | |
| SIMBAD | data |
HD 198404 (HR 7975) is a star in the equatorial constellation Delphinus. It has an apparent magnitude of 6.19,[2] allowing it to be faintly seen with the naked eye. Parallax measurements place the object at a distance of 395 light years[1] and it is approaching the Solar System with a heliocentric radial velocityof−21.6 km/s.[5]
HD 198404 has a simple stellar classification of K0,[3] indicating that it is a K-type star. Its enlarged diameterof10.54 R☉[8] and its low surface gravity[7] suggest that it has evolved away from the main sequence to become a giant star.[7] HD 198404 has 3.12 times the mass of the Sun[7] and radiates at 56 times the luminosity of the Sun[9] from its photosphere at an effective temperatureof4,809 K,[10] giving it a yellowish orange hue. The star is metal enriched, having an iron abundance 48% greater than that of the Sun.[7]
HD 198404 has an optical companion located 78.2″ away along a position angleof127° (as of 2014).[13]
