40 Aurigae is a binary star in the constellation Auriga. Its apparent magnitude is 5.345,[2] meaning it can just barely be seen with the naked eye. Based on parallax estimates made by the Hipparcos spacecraft, the system is located some 340 light-years (104 parsecs) away.[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 06h 06m 35.09702s[1] |
| Declination | +38° 28′ 57.5204″[1] |
| Apparent magnitude (V) | 5.345[2] |
| Characteristics | |
| Spectral type | A4m[3] |
| U−B color index | +0.11[4] |
| B−V color index | +0.23[4] |
| Astrometry | |
| Radial velocity (Rv) | 16.90 ± 7.4[5] km/s |
| Proper motion (μ) | RA: 9.84[1] mas/yr Dec.: −52.54[1] mas/yr |
| Parallax (π) | 9.57 ± 0.34 mas[1] |
| Distance | 340 ± 10 ly (104 ± 4 pc) |
| Orbit[3] | |
| Primary | 40 Aur A |
| Companion | 40 Aur B |
| Period (P) | 28.28 d |
| Eccentricity (e) | 0.56 |
| Periastron epoch (T) | JD 2420468.197 |
| Argument of periastron (ω) (secondary) | 178.4° |
| Semi-amplitude (K1) (primary) | 51.4 km/s |
| Semi-amplitude (K2) (secondary) | 62.5 km/s |
| Details[6] | |
| Surface gravity (log g) | 3.88 ± 0.08 cgs |
| Temperature | 7838 ± 52 K |
| Metallicity [Fe/H] | +0.35 ± 0.05 dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
40 Aurigae is a spectroscopic binary, meaning the two stars are too close to be individually resolved, but periodic Doppler shifts in their spectra indicate there must be orbital motion. In this case, light from both stars can be detected and it is a double-lined spectroscopic binary.[3] The two have an orbital period of 28.28 days and a fairly high eccentricity of 0.56.[3] The primary star is an A-type main-sequence star and shows unusual absorption lines in its spectrum, so it is an Am star[3] with an effective temperature of 7,838 K.[6]
References
edit- ^ a b c d e f 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 e Pourbaix, D.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
- ^ 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.
- ^ Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. S2CID 119323941.
- ^ a b Koleva, M.; Vazdekis, A. (2012). "Stellar population models in the UV. I. Characterisation of the New Generation Stellar Library". Astronomy & Astrophysics. 538: A143. arXiv:1111.5449. Bibcode:2012A&A...538A.143K. doi:10.1051/0004-6361/201118065. S2CID 53999614.