CP Boötis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 33m 20.26330s[1] |
| Declination | +36° 57′ 32.4483″[1] |
| Apparent magnitude (V) | 6.40[2] |
| Characteristics | |
| Evolutionary stage | subgiant[3] |
| Spectral type | F8 IVw[4] |
| U−B color index | 0.07[2] |
| B−V color index | 0.51[2] |
| Variable type | δ Sct[5] |
| Astrometry | |
| Radial velocity (Rv) | +5.9[6] km/s |
| Proper motion (μ) | RA: +2.694[1] mas/yr Dec.: −73.096[1] mas/yr |
| Parallax (π) | 12.9135 ± 0.0244 mas[1] |
| Distance | 252.6 ± 0.5 ly (77.4 ± 0.1 pc) |
| Absolute magnitude (MV) | 2.05[2] |
| Details | |
| Mass | 1.77[6] M☉ |
| Luminosity | 12.0+1.5 −1.3[7] L☉ |
| Surface gravity (log g) | 3.67[6] cgs |
| Temperature | 6,276[6] K |
| Metallicity [Fe/H] | 0.25[6] dex |
| Rotational velocity (v sin i) | 5.7[3] km/s |
| Age | 1.70[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
CP Boötis is a yellow-white hued star in the northern constellation of Boötes. With a baseline apparent visual magnitude of 6.40,[2] it is at or near the lower limit for visibility with the typical naked eye in good viewing conditions. The distance to this star can be estimated from its annual parallax shift of 12.91 mas,[1] which yields a range of 252.6 light years. It is moving further away with a heliocentric radial velocity of +5.9 km/s.[6]
In May of 1977, Michel Auvergne et al. inadvertently discovered that the star is a variable star, when they used it as a comparison star for photometric observations of gamma Boötis.[9] It was given its variable star designation, CP Boötis, in 1981.[10]
This is an F-type subgiant star with a stellar classification of F8 IVw,[4] which indicates it has nearly consumed the hydrogen at its core and is now evolving into a giant star. It is a low amplitude Delta Scuti variable[11] that varies by 0.02 magnitude.[12] At the age of 1.7[6] billion years it is spinning with a projected rotational velocity of 5.7 km/s.[3] The star has 1.77[6] times the mass of the Sun and is radiating 12[7] times the Sun's luminosity from its photosphere at an effective temperature of 6,276 K.[6]
References
[edit]- ^ a b c d e f 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.
- ^ a b c d e Karatas, Y.; Schuster, W. J. (October 2006), "Metallicity and absolute magnitude calibrations for UBV photometry", Monthly Notices of the Royal Astronomical Society, 371 (4): 1793–1812, Bibcode:2006MNRAS.371.1793K, doi:10.1111/j.1365-2966.2006.10800.x.
- ^ a b c Lèbre, A.; et al. (1999), "Lithium and rotation on the subgiant branch. I. Observations and spectral analysis", Astronomy and Astrophysics, 345: 936, Bibcode:1999A&A...345..936L.
- ^ a b Barry, Don C. (January 1970), "Spectral classification of A & F stars", Astrophysical Journal Supplement, 19: 281, Bibcode:1970ApJS...19..281B, doi:10.1086/190209
- ^ Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (2017), "General catalogue of variable stars: Version GCVS 5.1", Astronomy Reports, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
See: CP Boo - ^ a b c d e f g h i j Casagrande, L.; et al. (June 2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy and Astrophysics, 530: A138, arXiv:1103.4651, Bibcode:2011A&A...530A.138C, doi:10.1051/0004-6361/201016276, S2CID 56118016.
- ^ a b do Nascimento, J. D. Jr.; et al. (May 2000), "Lithium and rotation on the subgiant branch. II. Theoretical analysis of observations", Astronomy and Astrophysics, 357: 931–937, arXiv:astro-ph/0003010, Bibcode:2000A&A...357..931D.
- ^ "HD 127986". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 23 August 2018.
- ^ Auvergne, M.; Le Contel, J. M.; Sareyan, J. P.; Valtier, J. C.; Daguillon, J. (November 1977). "Observations of the Star gamma Bootis and of the New Variable Star HR 5441" (PDF). Information Bulletin on Variable Stars. 1365. Bibcode:1977IBVS.1365....1A. Retrieved 5 December 2024.
- ^ Kholopov, P. N.; Samus, N. N.; Kukarkina, N. P.; Medvedeva, G. I.; Perova, N. B. (February 1981). "65th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 1921: 1–21. Bibcode:1981IBVS.1921....1K. Retrieved 5 December 2024.
- ^ Galeev, A. I.; et al. (November 2012), "Chemical composition of δ Scuti stars: 1. AO CVn, CP Boo, KW Aur", Astronomy Reports, 56 (11): 850–866, Bibcode:2012ARep...56..850G, doi:10.1134/S1063772912110029, S2CID 124127339
- ^ Watson, Christopher (January 4, 2010), "CP Boötis", AAVSO Website, American Association of Variable Star Observers, retrieved 3 August 2014.
