Lambda Cassiopeiae
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cassiopeia |
Right ascension | 00h 31m 46.35935s[1] |
Declination | +54° 31′ 20.2257″[1] |
Apparent magnitude (V) | 4.772[2] (5.33 / 5.62)[3] |
Characteristics | |
Spectral type | B8 Vnn[4] |
U−B color index | −0.35[5] |
B−V color index | −0.10[5] |
Astrometry | |
Radial velocity (Rv) | ±1.3 −12.20[6] km/s |
Proper motion (μ) | RA: ±0.29 +41.20[1] mas/yr Dec.: ±0.35 −16.54[1] mas/yr |
Parallax (π) | 8.64 ± 0.43[1] mas |
Distance | 380 ± 20 ly (116 ± 6 pc) |
Absolute magnitude (MV) | −0.57[4] |
Orbit[3] | |
Period (P) | ±35.96 245.70yr |
Semi-major axis (a) | ±0.028″ 0.448 |
Eccentricity (e) | ±0.119 0.689 |
Inclination (i) | ±5.2 53.6° |
Longitude of the node (Ω) | ±9.6 17.6° |
Periastron epoch (T) | 025.54±4.56 2 |
Argument of periastron (ω) (secondary) | ±2.6 301.0° |
Details | |
λ Cas A | |
Mass | +0.45 −0.40 2.9[7] M☉ |
Radius | 3.50[8] R☉ |
Luminosity | 255[4] L☉ |
Surface gravity (log g) | ±0.25 4.0[7] cgs |
Temperature | ±1,000 12,000[7] K |
Rotational velocity (v sin i) | 253[9] km/s |
Age | +104 −48 58[7] Myr |
Other designations | |
Database references | |
SIMBAD | λ Cas |
λ Cas A | |
λ Cas B |
Lambda Cassiopeiae, Latinized from λ Cassiopeiae, is a binary star system, in the northern constellation of Cassiopeia. The system has a combined apparent magnitude of +4.74, making it faintly visible to the naked eye. With an annual parallax shift of 8.64 mass,[1] it is approximately 380 light years from Earth. The system is moving closer to the Sun with a radial velocity of −12 km/s.[6]
Both components are blue-white B-type main-sequence stars. The brighter member, component A, has an apparent magnitude of +5.5, while its companion, component B, has an apparent magnitude of +5.8. The two stars are separated by 0.6 arcseconds and complete one orbit around their common centre of mass about once every 250 years.[3] The primary displays an infrared excess, possibly due to a debris disk or other orbiting material.[8]
References
- 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. Vizier catalog entry
- ↑ Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
- 1 2 3 "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Retrieved 16 May 2017.
- 1 2 3 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.
- 1 2 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Bibcode:1986EgUBV........0M.
- 1 2 Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776.
- 1 2 3 4 Gullikson, Kevin; et al. (August 2016). "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars". The Astronomical Journal. 152 (2): 13. arXiv:1604.06456. Bibcode:2016AJ....152...40G. doi:10.3847/0004-6256/152/2/40. 40.
- 1 2 Cotten, Tara H.; Song, Inseok (July 2016), "A Comprehensive Census of Nearby Infrared Excess Stars", The Astrophysical Journal Supplement Series, 225 (1): 24, arXiv:1606.01134, Bibcode:2016ApJS..225...15C, doi:10.3847/0067-0049/225/1/15, 15
- ↑ Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691.