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BP Circini 
Summary
BP Circini is a binary star system in the southern constellation of Circinus. It is located at a distance of approximately 3,300 light years from the Sun based on parallax.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Circinus |
| Right ascension | 14h 46m 41.98011s[2] |
| Declination | −61° 27′ 42.9903″[2] |
| Apparent magnitude (V) | 7.37 - 7.71[3] |
| Characteristics | |
| Spectral type | F2/3II + B6V[4] |
| B−V color index | 0.649±0.020[5] |
| Astrometry | |
| Proper motion (μ) | RA: −5.355[2] mas/yr Dec.: −3.920[2] mas/yr |
| Parallax (π) | 0.9952 ± 0.0402 mas[2] |
| Distance | 3,300 ± 100 ly (1,000 ± 40 pc) |
| Absolute magnitude (MV) | −2.91[6] |
| Orbit[6] | |
| Period (P) | 20 yr |
| Semi-major axis (a) | 15.8 AU |
| Details | |
| A | |
| Mass | 5[7] M☉ |
| Radius | 30.38+6.93 −6.50[2] R☉ |
| Luminosity | 917±54[2] L☉ |
| Surface gravity (log g) | 2.75[8] cgs |
| Temperature | 6356±23[8] K |
| B | |
| Mass | 4.7[6] M☉ |
| Surface gravity (log g) | 4.0±0.5[7] cgs |
| Temperature | 16,000±1,000[7] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
The variability of this star was discovered by D. W. Kurtz in 1979.[7] A small-amplitude Cepheid variable,[8] its apparent magnitude ranges from 7.37 to 7.71 over 2.39810 days.[3] A spectroscopic binary, the primary is a yellow-white bright giant of spectral type F2 or F3II.[4] The spectrum shows peculiarities in the metallic lines.[10] The secondary is a 4.7 solar mass (M☉) blue-white main sequence star of spectral type B6.[6]
References edit
- ^ "Hipparcos Tools Interactive Data Access". Hipparcos. ESA. Retrieved 8 December 2021.
- ^ a b c d e f g h 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 BSJ (30 November 2013). "BP Circini". AAVSO Website. American Association of Variable Star Observers. Retrieved 24 January 2014.
- ^ a b Skiff, B. A. (October 2014), "General Catalogue of Stellar Spectral Classifications", VizieR Online Data Catalog, Bibcode:2014yCat....1.2023S
- ^ 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 Evans, Nancy Remage; et al. (2013). "Binary Cepheids: Separations and Mass Ratios in 5M ⊙ Binaries". Astronomical Journal. 146 (4): 93, 10 pp. arXiv:1307.7123. Bibcode:2013AJ....146...93E. doi:10.1088/0004-6256/146/4/93. S2CID 34133110.
- ^ a b c d Petterson, O. K. L.; et al. (May 2004). "The orbits of southern binary Cepheids". Monthly Notices of the Royal Astronomical Society. 350 (1): 95–112. Bibcode:2004MNRAS.350...95P. doi:10.1111/j.1365-2966.2004.07555.x.
- ^ a b c Usenko, I. A.; et al. (December 2014). "Spectroscopic studies of Cepheids in Circinus (AV Cir, BP Cir) and Triangulum Australe (R TrA, S TrA, U TrA, LR TrA)". Astronomy Letters. 40 (12): 800–820. Bibcode:2014AstL...40..800U. doi:10.1134/S1063773714110061. S2CID 122745580.
- ^ "V* BP Cir". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 24 January 2014.
- ^ Kurtz, D. W. (1979). "HD 129708: A New, Bright, Short-Period Cepheid with an Unusual Spectrum". Monthly Notes of the Astronomical Society of Southern Africa. 38: 36. Bibcode:1979MNSSA..38...36K.