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26 Aurigae
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
Distance163 [4]  pc
Absolute magnitude (MV)−0.29 [7]
Orbit [4]
Primary26 Aur A
Companion26 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
Mass2.1 ± 1.0 [4]  M
26 Aur B
Mass3.0 ± 0.4 [4]  M
Other designations
26 Aur, BD+30°963, GC 7002, HD 37269, HIP 26536, HR 1914, SAO 58280, PPM 70656, ADS 4229, WDS J05386+3030, GSC 02404-01350
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. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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.
  8. ^ 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.
  9. ^ 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.
  10. ^ 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.