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B Persei 
Summary
b Persei (also known as HD 26961) is a spectroscopic triple star in the constellation Perseus. Its apparent magnitude is 4.60,[6] and it is about 320 light years away.[1]
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Perseus |
| Right ascension | 04h 18m 14.61690s[1] |
| Declination | +50° 17′ 43.8058″[1] |
| Apparent magnitude (V) | 4.52 - 4.68[2] |
| Characteristics | |
| Spectral type | A1III[3] |
| B−V color index | +0.04[4] |
| Variable type | Ellipsoidal[2] |
| Astrometry | |
| Radial velocity (Rv) | 19.8±0.9[5] km/s |
| Proper motion (μ) | RA: 45.42±0.40[1] mas/yr Dec.: −56.72±0.32[1] mas/yr |
| Parallax (π) | 10.40 ± 0.35 mas[1] |
| Distance | 310 ± 10 ly (96 ± 3 pc) |
| Absolute magnitude (MV) | 0.3[6] |
| Orbit[7] | |
| Primary | A or Aa |
| Companion | C or Ac |
| Period (P) | 701.76 days |
| Semi-major axis (a) | 5.09 mas |
| Eccentricity (e) | 0.235 |
| Inclination (i) | 83.46° |
| Longitude of the node (Ω) | 115.29° |
| Periastron epoch (T) | 2440143.3984 |
| Argument of periastron (ω) (secondary) | 263° |
| Details | |
| A or Aa | |
| Mass | 2.25[6] M☉ |
| Radius | 3.2[8] R☉ |
| Luminosity | 10[9] L☉ |
| Temperature | 9000[6] K |
| Rotational velocity (v sin i) | 81[10] km/s |
| B or Ab | |
| Mass | 0.56[11] M☉ |
| Radius | 0.25[8] R☉ |
| C or Ac | |
| Mass | 1.24[11] M☉ |
| Luminosity | 2[9] L☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
In addition to the primary, an A-type giant, there is a smaller and cooler companion in a 1.53 day orbit, probably an F-class star around absolute magnitude 3.0, and a more distant companion (star C or Ac) in an orbit calculated to be 702 days long.[6] The close binary pair forms a rotating ellipsoidal variable with a 1.53 day period. Star C forms an Algol-type variable system with the close binary, showing both primary eclipses (when star C passes in front of the inner pair) and secondary eclipses (when the inner pair passes in front of star C).[14] Timings of the eclipses show a 705.4-day period.[9]
References edit
- ^ a b c d e f 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. Vizier catalog entry
- ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- ^ Abt, Helmut A. (2009). "MK Classifications of Spectroscopic Binaries". The Astrophysical Journal Supplement. 180 (1): 117–18. Bibcode:2009ApJS..180..117A. doi:10.1088/0067-0049/180/1/117. S2CID 122811461.
- ^ 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. Vizier catalog entry
- ^ Wilson, R. E. (1953). General Catalogue of Stellar Radial Velocities. Carnegie Institution for Science. Bibcode:1953GCRV..C......0W. LCCN 54001336.
- ^ a b c d e Hill, G.; Aikman, G. C. L.; Cowley, A. P.; Bolton, C. T.; Thomas, J. C. (1976). "The radio-flaring triple system B Per". The Astrophysical Journal. 208: 152. Bibcode:1976ApJ...208..152H. doi:10.1086/154590.
- ^ ESA (1997). "The Hipparcos and Tycho Catalogues". VizieR On-line Data Catalog. 1239. Bibcode:1997yCat.1239....0E.
- ^ a b Duerbeck, H. W.; Schettler, A. (1979). "Photometric and spectroscopic study of the ellipsoidal variable b Persei". Acta Astronomica. 29: 225. Bibcode:1979AcA....29..225D.
- ^ a b c "Alert Notice 791: Anticipated secondary eclipse of b Per centered on September 29 2022 UT". AAVSO. Retrieved 2022-09-15.
- ^ Royer, F. (2007). "Rotational velocities of A-type stars. III. Velocity distributions". Astronomy and Astrophysics. 463 (2): 671–682. arXiv:astro-ph/0610785. Bibcode:2007A&A...463..671R. doi:10.1051/0004-6361:20065224. S2CID 18475298.
- ^ a b Tokovinin, Andrei (23 February 2018). "The Updated Multiple Star Catalog". The Astrophysical Journal Supplement Series. 235 (1): 6. arXiv:1712.04750. Bibcode:2018ApJS..235....6T. doi:10.3847/1538-4365/aaa1a5. eISSN 1538-4365.
- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 14 September 2022.
- ^ "Download Data". aavso.org. AAVSO. Retrieved 14 September 2022.
- ^ "b Per". The International Variable Star Index. AAVSO. Retrieved 15 September 2022.