HR 7955

Last updated
HR 7955
Observation data
Epoch J2000        Equinox J2000
Constellation Cepheus [1]
Right ascension 20h 45m 21.12879s [2]
Declination +57° 34′ 47.0080″ [2]
Apparent magnitude  (V)4.51 [3]
Characteristics
Spectral type F8IV-V + F9IV-V [3]
Astrometry
Radial velocity (Rv)−32.82±0.04 [4] km/s
Proper motion (μ)RA: −62.32 [2] mas/yr
Dec.: −236.00 [2] mas/yr
Parallax (π)36.64±0.48  mas [2]
Distance 89 ± 1  ly
(27.3 ± 0.4  pc)
Absolute magnitude  (MV)2.35 [5]
Orbit [3]
Period (P)494.16±0.58 d
Semi-major axis (a)0.065±0.001"
(≥50.2±0.5  Gm [6] )
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 [3]
HR 7955 A
Mass 1.071±0.037  M☉
Age 2.25 [7]   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 [8]
Database references
SIMBAD data

HR 7955 is a binary star [3] 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. [3] The system is located at a distance of 89 light-years (27.3 parsecs) from the Sun, based on parallax. [2] It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.243  arc seconds per annum, [9] and is drifting closer to the Sun with a radial velocity of -33 km/s. [4]

The double-lined nature of this spectroscopic binary system was not announced until 1972. [6] It has an orbital period of 1.35 years and an eccentricity of 0.551. [3] 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. [3] The system is about 2.25 billion years old. [7]

This star is occasionally known as Upsilon Cephei (υ Cephei). According to the Bright Star Catalogue, this Bayer designation appeared in Elijah H. Burritt's star atlas but is not confirmed elsewhere. [10] Nevertheless, it is listed in the SIMBAD database. [8] R. H. Allen's Star Names erroneously states that "υ1 and υ2" Cephei were given the name Castula by Bayer; [11] this was actually the name of υ1 and υ2 Cassiopeiae, now officially applied to the latter. [12]

References

  1. ↑ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.
  2. 1 2 3 4 5 6 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752 . Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID   18759600.
  3. 1 2 3 4 5 6 7 8 Farrington, C. D.; et al. (2010). "Separated Fringe Packet Observations with the CHARA Array. I. Methods and New Orbits for χ Draconis, HD 184467, and HD 198084". The Astronomical Journal. 139 (6): 2308. Bibcode:2010AJ....139.2308F. doi:10.1088/0004-6256/139/6/2308. S2CID   122357261.
  4. 1 2 Pourbaix, D.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv: astro-ph/0406573 . Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID   119387088.
  5. ↑ Griffin, R. F.; Suchkov, A. A. (July 2003). "The Nature of Overluminous F Stars Observed in a Radial-Velocity Survey". The Astrophysical Journal Supplement Series. 147 (1): 103–144. Bibcode:2003ApJS..147..103G. doi: 10.1086/367855 .
  6. 1 2 Griffin, R. F. (October 1999), "Spectroscopic binary orbits from photoelectric radial velocities. Paper 148: HR 7955", The Observatory, 119: 272–283, Bibcode:1999Obs...119..272G
  7. 1 2 Luck, R. Earle (January 2017), "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants", The Astronomical Journal, 153 (1): 19, arXiv: 1611.02897 , Bibcode:2017AJ....153...21L, doi: 10.3847/1538-3881/153/1/21 , S2CID   119511744, 21.
  8. 1 2 "HD 198084". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 6 September 2012.
  9. ↑ Lépine, Sébastien; Shara, Michael M. (March 2005). "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)". The Astronomical Journal. 129 (3): 1483–1522. arXiv: astro-ph/0412070 . Bibcode:2005AJ....129.1483L. doi:10.1086/427854. S2CID   2603568.
  10. ↑ Hoffleit, D.; Warren, W. H. Jr. (November 1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". Vizier Online Data Catalog. Bibcode:1995yCat.5050....0H. Remarks for HR 7955
  11. ↑ Allen, R. H. (1899), Star Names: Their Lore and Meaning, p. 159
  12. ↑ "IAU Catalog of Star Names" . Retrieved 24 April 2025.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.