Omega2 Cancri
ω2 Cancri is a star in the zodiac constellation Cancer, located around 810 light years away from the Sun. It has the Flamsteed designation 4 Cancri; ω2 Cancri is the Bayer designation, which is Latinised to omega2 Cancri and abbreviated to ω2 Cnc or omega2 Cnc. The star is near the lower limit of visibility to the naked eye, having an apparent visual magnitude of 6.32.[2] It is moving closer to the Earth with a heliocentric radial velocity of −8 km/s.[5] The position of this star near the ecliptic means it is subject to lunar occultations.[8]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 01m 43.75679s[1] |
| Declination | +25° 05′ 22.0823″[1] |
| Apparent magnitude (V) | 6.32[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | A1 V[4] |
| B−V color index | 0.023±0.006[2] |
| Astrometry | |
| Radial velocity (Rv) | −7.6±2.5[5] km/s |
| Proper motion (μ) | RA: −25.112[1] mas/yr Dec.: +12.038[1] mas/yr |
| Parallax (π) | 7.4046 ± 0.0486 mas[1] |
| Distance | 440 ± 3 ly (135.1 ± 0.9 pc) |
| Absolute magnitude (MV) | 0.51[2] |
| Details | |
| Mass | 2.59±0.06[3] M☉ |
| Radius | 2.5[6] R☉ |
| Luminosity | 68.0+8.3 −7.3[3] L☉ |
| Temperature | 9,354+174 −171[3] K |
| Rotational velocity (v sin i) | 159[3] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an ordinary A-type main-sequence star with a stellar classification of A1 V,[4] which indicates it is generating energy through hydrogen fusion at its core. It has 2.6[3] times the mass of the Sun and about 2.5[6] times the Sun's radius. The star is radiating 68[3] times the Sun's luminosity from its photosphere at an effective temperature of 9354 K.[3]
References edit
- ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d 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, S2CID 119257644.
- ^ a b c d e f g h Zorec, J.; et al. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy and Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
- ^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (Third ed.), 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ "ome02 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-02-23.
- ^ Schmidtke, P. C.; Africano, J. L. (2011), "KPNO Lunar Occultation Summary. III", The Astronomical Journal, 141 (1): 10, Bibcode:2011AJ....141...10S, doi:10.1088/0004-6256/141/1/10.