Gamma Cassiopeiae

γ Cassiopeiae
Location of γ Cassiopeiae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Cassiopeia
Right ascension 00h 56m 42.50108s[1]
Declination +60° 43′ 00.2984″[1]
Apparent magnitude (V) 2.47[2] (1.6 - 3.0[3])
Characteristics
Spectral type B0.5IVe[4]
U−B color index −1.08[2]
B−V color index −0.15[2]
Variable type γ Cas[3]
Astrometry
Radial velocity (Rv)−6.8[5] km/s
Proper motion (μ) RA: +25.17[1] mas/yr
Dec.: −3.92[1] mas/yr
Parallax (π)5.94 ± 0.12 mas[1]
Distance550 ± 10 ly
(168 ± 3 pc)
Absolute magnitude (MV)−3.98[6]
Orbit[4]
PrimaryAa
CompanionAb
Period (P)203.523±0.076 d
Eccentricity (e)0
Inclination (i)45°
Semi-amplitude (K1)
(primary)		4.297±0.090 km/s
Orbit[7]
PrimaryAab
CompanionAc
Period (P)60.0 yr
Semi-major axis (a)0.15″
Details
Aa
Mass13[4] M☉
Radius10[8] R☉
Luminosity34,000[8] L☉
Surface gravity (log g)3.50[8] cgs
Temperature25,000[8] K
Rotational velocity (v sin i)432[9] km/s
Age8.0±0.4[9] Myr
Ab
Mass0.98[4] M☉
Other designations
Tsih,[10] γ Cas, 27 Cassiopeiae, ADS 782, BD+59°144, FK5 32, HD 5394, HIP 4427, HR 264, SAO 11482, WDS 00567+6043, AAVSO 0050+60[11]
Database references
SIMBADdata

Gamma Cassiopeiae, Latinized from γ Cassiopeiae, is a bright star at the center of the distinctive "W" asterism in the northern circumpolar constellation of Cassiopeia. Although it is a fairly bright star with an apparent visual magnitude that varies from 1.6 to 3.0, it has no traditional Arabic or Latin name. It sometimes goes by the informal name Navi. It was observed 1866 by Angelo Secchi, the first star ever observed with emission lines.[12][13] It is now considered a Be star.

Gamma Cassiopeiae is also a variable star and a multiple star system. Based upon parallax measurements made by the Hipparcos satellite, it is located at a distance of roughly 550 light-years from Earth. Together with its common-proper-motion companion, HD 5408, the system could contain a total of eight stars.[14] It is one of the highest multiplicity systems known.[13]

  1. ^ a b c d e Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference aass34_1 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference gcvs was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference nemravova was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference gcsrv was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference msc was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference ApJ668_1_481 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference zorec was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference falkner was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Secchi, A. (1867). "Schreiben des Herrn Prof.Secchi, Dir. Der Sternwarte des Collegio Romano, an den Herausgeber". Astronomische Nachrichten. 68 (4): 63–64. Bibcode:1866AN.....68...63S. doi:10.1002/asna.18670680405.
  13. ^ a b Mamajek, Eric (April 2017). "Gamma Cassiopeiae and HR 266: A Massive Septuplet Illuminating the IC 59 and IC 63 Nebulae at d = 168 pc". Journal of Double Star Observations. 13 (2): 264–267. Bibcode:2017JDSO...13..264M.
  14. ^ Cite error: The named reference Hutter was invoked but never defined (see the help page).