28 Cancri
28 Cancri is a star system in the zodiac constellation of Cancer. It is a variable star with the designation CX Cancri, and is close to the lower limit of visibility with the naked eye, having a mean apparent visual magnitude of 6.05.[2] The annual parallax shift seen from Earth's orbit is 7.32 mas, which provides a distance estimate of about 450 light years. It is moving away from the Sun with a radial velocity of around +9 km/s.[5]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cancer |
Right ascension | 08h 28m 36.78559s[1] |
Declination | +24° 08′ 41.7194″[1] |
Apparent magnitude (V) | 6.05[2] |
Characteristics | |
Spectral type | F0 Vn[3] |
U−B color index | +0.13[2] |
B−V color index | +0.22[2] |
Variable type | δ Sct[4] |
Astrometry | |
Radial velocity (Rv) | +9.0±4.3[5] km/s |
Proper motion (μ) | RA: −29.07[1] mas/yr Dec.: −52.84[1] mas/yr |
Parallax (π) | 7.32 ± 0.92[1] mas |
Distance | approx. 450 ly (approx. 140 pc) |
Absolute magnitude (MV) | 0.41[6] |
Details | |
Mass | 2.36±0.11[7] M☉ |
Luminosity | 65.3+21.2 −16.0[7] L☉ |
Temperature | 7,516+52 −103[7] K |
Rotational velocity (v sin i) | 133[7] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Based upon proper motion variation, this is an astrometric binary system with high likelihood (99.8%).[9] The visible component has a stellar classification of F0 Vn,[3] indicating it is a F-type main-sequence star with "nebulous" lines due to rapid rotation. It is a Delta Scuti variable star with a period of 0.0960 days and an amplitude of 0.020 in magnitude.[10] With 2.4[7] times the mass of the Sun it is spinning with a high projected rotational velocity of 133 km/s.[7] 28 Cancri is radiating roughly 65[7] times the Sun's luminosity from its photosphere at an effective temperature of around 7,516 K.[7]
References
- 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.
- Oja, T. (August 1991), "UBV photometry of stars whose positions are accurately known. VI", Astronomy and Astrophysics Supplement Series, 89 (2): 415–419, Bibcode:1991A&AS...89..415O.
- 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.
- Dubath, P.; et al. (2011), "Random forest automated supervised classification of Hipparcos periodic variable stars", Monthly Notices of the Royal Astronomical Society, 414 (3): 2602–2617, arXiv:1101.2406, Bibcode:2011MNRAS.414.2602D, doi:10.1111/j.1365-2966.2011.18575.x, S2CID 118560311.
- 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.
- 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.
- Zorec, J.; Royer, F. (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, S2CID 55586789, A120.
- "28 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-09.
- Frankowski, A.; et al. (March 2007), "Proper-motion binaries in the Hipparcos catalogue. Comparison with radial velocity data", Astronomy and Astrophysics, 464 (1): 377–392, arXiv:astro-ph/0612449, Bibcode:2007A&A...464..377F, doi:10.1051/0004-6361:20065526, S2CID 14010423.
- Rodríguez, E.; et al. (June 2000), "A revised catalogue of δ Sct stars", Astronomy and Astrophysics Supplement, 144 (3): 469–474, Bibcode:2000A&AS..144..469R, doi:10.1051/aas:2000221.