| Observation data EpochJ2000 EquinoxJ2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 20h 45m 21.12879s[1] |
| Declination | +57° 34′ 47.0080″[1] |
| Apparent magnitude (V) | 4.51[2] |
| Characteristics | |
| Spectral type | F8IV-V + F9IV-V[2] |
| Astrometry | |
| Radial velocity (Rv) | −32.82±0.04[3] km/s |
| Proper motion (μ) | RA: −62.32[1]mas/yr Dec.: −236.00[1]mas/yr |
| Parallax (π) | 36.64±0.48 mas[1] |
| Distance | 89 ± 1 ly (27.3 ± 0.4 pc) |
| Absolute magnitude (MV) | 2.35[4] |
| Orbit[2] | |
| Period (P) | 494.16±0.58 d |
| Semi-major axis (a) | 0.065±0.001" (≥50.2±0.5 Gm[5]) |
| Eccentricity (e) | 0.551±0.004 |
| Inclination (i) | 24.53±3.13° |
| Longitude of the node (Ω) | 325.21±1.05° |
| Periastronepoch (T) | B 1996.335 ± 0.0017 |
| Argument of periastron (ω) (secondary) | 68.86±0.76° |
| Details[2] | |
| HR 7955 A | |
| Mass | 1.071±0.037 M☉ |
| Age | 2.25[6] Gyr |
| HR 7955 B | |
| Mass | 1.047±0.037 M☉ |
| Other designations | |
| BD+57°2240,FK5 782,GJ 9706,HD 198084,HIP 102431,HR 7955,SAO 32862[7] | |
| Database references | |
| SIMBAD | data |
HR 7955 is abinary star[2] system in the northerncircumpolar constellation ofCepheus, near the constellation border withCygnus. It has a yellow-white hue and is faintly visible to the naked eye with a combinedapparent visual magnitude of 4.51.[2] The system is located at a distance of 89 light-years (27.3 parsecs) from theSun, based onparallax.[1] It has a relatively highproper motion, traversing thecelestial sphere at the rate of 0.243 arc seconds per annum,[8] and is drifting closer to the Sun with aradial velocity of -33 km/s.[3]
The double-lined nature of thisspectroscopic binary system was not announced until 1972.[5] It has anorbital period of 1.35 years and aneccentricity of 0.551.[2] Both components appear to be slightlyevolved stars that are leaving themain sequence and becomingsubgiant stars, withstellar classifications of F8IV-V and F9IV-V. They each have slightly greater mass than the Sun: 107% and 105%, respectively.[2] The system is about 2.25 billion years old.[6]
