Summary
26 Aurigae is a binary star[3] system in the northern constellation of Auriga. It is visible to the naked eye as a faint star with an apparent visual magnitude of 5.41.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 38m 38.08510s[1] |
| Declination | +30° 29′ 32.7054″[1] |
| Apparent magnitude (V) | 5.406[2] (6.29 / 6.21)[3] |
| Characteristics | |
| Spectral type | G8III + A1IV or B9.5V[4] |
| U−B color index | +0.25[5] |
| B−V color index | +0.45[5] |
| Variable type | suspected[6] |
| Astrometry | |
| Proper motion (μ) | RA: -21.32[1] mas/yr Dec.: -10.10[1] mas/yr |
| Distance | 163[4] pc |
| Absolute magnitude (MV) | −0.29[7] |
| Orbit[4] | |
| Primary | 26 Aur A |
| Companion | 26 Aur B |
| Period (P) | 52.735±0.156 yr |
| Semi-major axis (a) | 0.154±0.001" (21.1+3.2 −2.4 AU) |
| Eccentricity (e) | 0.653±0.002 |
| Inclination (i) | 124.22±0.29° |
| Longitude of the node (Ω) | 127.08±0.38° |
| Periastron epoch (T) | 1974.927±0.026 |
| Argument of periastron (ω) (secondary) | 309.07±0.14° |
| Details | |
| 26 Aur A | |
| Mass | 2.1 ± 1.0[4] M☉ |
| 26 Aur B | |
| Mass | 3.0 ± 0.4[4] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The distance to this system remains poorly constrained. The new Hipparcos reduction gives a parallax of 5.76±6.42.[1] The original Hipparcos parallax was given as 7.29±0.96,[8] leading to a distance of 137.2+20.8
−16.0 pc being assumed in many texts. A distance of 163 pc has been derived from fitting the spectrum.[4]
26 Aurigae is a visual binary system, and the two stars orbit each other every 52.735 years with an ellipticity of 0.653 and an angular separation 0.154″.[4] The system is made of a magnitude 6.29[3] G-type red giant, and a hotter magnitude 6.21[3] star that has been classified as an early B-type main-sequence star to an A-type subgiant star.[4] Component A is the cool giant star, the brighter but less massive of the pair.[9][4] The hotter star is sometimes listed as the primary on the basis of its stronger showing in the blended spectrum.[10]
References edit
- ^ a b c d e van Leeuwen, F.; et al. (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.
- ^ a b Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
- ^ a b c d Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ a b c d e f g h i Rica Romero, F. M. (2008). "Orbital Elements for BU 1240 AB. Nature of the C and D Components". Revista Mexicana de Astronomía y Astrofísica. 44: 137–147. Bibcode:2008RMxAA..44..137R.
- ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- ^ 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: B/gcvs. Bibcode:2009yCat....102025S.
- ^ Ginestet, N.; Carquillat, J. M. (2002). "Spectral Classification of the Hot Components of a Large Sample of Stars with Composite Spectra, and Implication for the Absolute Magnitudes of the Cool Supergiant Components". The Astrophysical Journal Supplement Series. 143 (2): 513. Bibcode:2002ApJS..143..513G. doi:10.1086/342942.
- ^ M. A. C. Perryman; European Space Agency; FAST Consortium (1997). The Hipparcos and Tycho catalogues: astrometric and photometric star catalogues derived from the ESA Hipparcos Space Astrometry Mission. ESA Publications Division. ISBN 978-92-9092-399-2.
- ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
- ^ Abt, Helmut A. (2008). "Visual Multiples. IX. MK Spectral Types". The Astrophysical Journal Supplement Series. 176 (1): 216–217. Bibcode:2008ApJS..176..216A. doi:10.1086/525529.