Omega Cassiopeiae

Omega Cassiopeiae

Map of the Bayer-designated stars in Cassiopeia. Omega Cassiopeiae is circled.
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cassiopeia
Right ascension 01h 56m 00.02830s[1]
Declination +68° 41′ 06.8639″[1]
Apparent magnitude (V) +4.99[2]
Characteristics
Spectral type B5 III[3]
U−B color index −0.41[4]
B−V color index −0.09[4]
Astrometry
Radial velocity (Rv)−24.8±4.2[5] km/s
Proper motion (μ) RA: 15.067[1] mas/yr
Dec.: −10.313[1] mas/yr
Parallax (π)4.4802 ± 0.0912 mas[1]
Distance730 ± 10 ly
(223 ± 5 pc)
Absolute magnitude (MV)+0.09[6]
Orbit[7]
Period (P)69.92 d
Eccentricity (e)0.30
Periastron epoch (T)2420426.02 JD
Argument of periastron (ω)
(secondary)		50°
Semi-amplitude (K1)
(primary)		29.6 km/s
Details
ω Cas A
Mass3.5[8] M☉
Radius2.7[8] R☉
Luminosity178[8] L☉
Surface gravity (log g)4.1[8] cgs
Temperature12,737±100[9] K
Rotational velocity (v sin i)45.7[10] km/s
Age232[6] Myr
Other designations
ω Cas, 46 Cas, BD+67°169, FK5 2129, HD 11529, HIP 9009, HR 548, SAO 12038[11]
Database references
SIMBADdata

Omega Cassiopeiae (ω Cassiopeiae) is a binary star[2] system in the northern constellation of Cassiopeia. It has a combined apparent visual magnitude of +4.99,[2] which means it is a faint star but visible to the naked eye. Based upon an annual parallax shift of 4.65 mas as seen from Earth,[12] this system is located roughly 730 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.16 due to interstellar dust.[6]

This is a single-lined spectroscopic binary star system with an orbital period of 69.92 days and an eccentricity of 0.30. The visible component has the spectrum of an evolved, B-type giant star with a stellar classification of B5 III.[3] It is a helium-weak star, a type of chemically peculiar star that displays abnormally weak absorption lines of helium for a star of its temperature.[13] Omega Cassiopeiae has an estimated 3.5 times the mass of the Sun and is radiating 178 times the Sun's luminosity from its photosphere at an effective temperature of around 12,737 K.[9]

  1. ^ a b c d e Cite error: The named reference edr3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference apj694_2_1085 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Crawford1963 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Pourbaix was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference TICv7 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Huang2010 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference moiseeva2019 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. ^ Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Renson2009 was invoked but never defined (see the help page).