HR 7955

HR 7955
Observation data
Epoch J2000      Equinox J2000
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]
Distance89 ± 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°
Periastron epoch (T)B 1996.335 ± 0.0017
Argument of periastron (ω)
(secondary)		68.86±0.76°
Details[2]
HR 7955 A
Mass1.071±0.037 M☉
Age2.25[6] Gyr
HR 7955 B
Mass1.047±0.037 M☉
Other designations
BD+57°2240, FK5 782, GJ 9706, HD 198084, HIP 102431, HR 7955, SAO 32862[7]
Database references
SIMBADdata

HR 7955 is a binary star[2] system in the northern circumpolar constellation of Cepheus, near the constellation border with Cygnus. It has a yellow-white hue and is faintly visible to the naked eye with a combined apparent visual magnitude of 4.51.[2] The system is located at a distance of 89 light-years (27.3 parsecs) from the Sun, based on parallax.[1] It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.243 arc seconds per annum,[8] and is drifting closer to the Sun with a radial velocity of -33 km/s.[3]

The double-lined nature of this spectroscopic binary system was not announced until 1972.[5] It has an orbital period of 1.35 years and an eccentricity of 0.551.[2] Both components appear to be slightly evolved stars that are leaving the main sequence and becoming subgiant stars, with stellar 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]

  1. ^ a b c d e f Cite error: The named reference HIP was invoked but never defined (see the help page).
  2. ^ a b c d e f g h Cite error: The named reference Farrington was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference SB9 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Griffin2003 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Griffin1999 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Earle2017 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Lepine2005 was invoked but never defined (see the help page).