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]