Astronomy:26 Aurigae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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 astronomical unit|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 |
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]
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
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL.
- ↑ 2.0 2.1 Høg, E. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode: 2000A&A...355L..27H.
- ↑ 3.0 3.1 3.2 3.3 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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 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.
- ↑ 5.0 5.1 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. 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. doi:10.1086/342942. Bibcode: 2002ApJS..143..513G.
- ↑ 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. https://books.google.com/books?id=qW3vAAAAMAAJ.
- ↑ 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. doi:10.1086/323920. Bibcode: 2001AJ....122.3466M.
- ↑ Abt, Helmut A. (2008). "Visual Multiples. IX. MK Spectral Types". The Astrophysical Journal Supplement Series 176 (1): 216–217. doi:10.1086/525529. Bibcode: 2008ApJS..176..216A.
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