45 Aurigae or PLX 1468.2 is a binary star[5] system in the northern constellation of Auriga. It has an apparent visual magnitude of 5.34,[2] making it visible to the naked eye under suitable viewing conditions. An annual parallax shift of 16.89 mas as seen from Earth's orbit indicates the system is located about 193 light years from the Sun.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 06h 21m 46.12968s[1] |
| Declination | +53° 27′ 07.8456″[1] |
| Apparent magnitude (V) | 5.34[2] |
| Characteristics | |
| Spectral type | F5 V[3][2] |
| B−V color index | 0.448±0.005[2] |
| Astrometry | |
| Radial velocity (Rv) | −0.4±0.1[4] km/s |
| Proper motion (μ) | RA: +21.98[1] mas/yr Dec.: -88.69[1] mas/yr |
| Parallax (π) | 16.89 ± 0.30 mas[1] |
| Distance | 193 ± 3 ly (59 ± 1 pc) |
| Absolute magnitude (MV) | 1.48[2] |
| Orbit[5] | |
| Period (P) | 6.5011 d |
| Eccentricity (e) | 0.000 |
| Periastron epoch (T) | 2444496.869 ± 0.006 JD |
| Argument of periastron (ω) (secondary) | 0.000° |
| Semi-amplitude (K1) (primary) | 32.0±0.2 km/s |
| Details | |
| 45 Aur A | |
| Mass | 1.20[6] M☉ |
| Luminosity | 21.72[2] L☉ |
| Surface gravity (log g) | 3.57±0.14[6] cgs |
| Temperature | 6,489±221[6] K |
| Metallicity [Fe/H] | 0.23±0.03[2] dex |
| Rotational velocity (v sin i) | 14[7] km/s |
| Age | 1.561[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a close, single-lined spectroscopic binary with a circularized orbit with a short period of 6.5 days.[5] They have a mean angular separation of 0.963 mas.[9] The visible component has a stellar classification of F5 V,[3] matching an F-type main-sequence star that is generating energy through hydrogen fusion at it core. It is about 1.6[6] billion years old and is spinning with a projected rotational velocity of 14 K.[7] It has 1.2[6] times the mass of the Sun and is radiating 22[2] times the Sun's luminosity from its photosphere at an effective temperature of around 6,489 K.[6] The secondary has a minimum mass of 42% of the Sun's mass.[9]
References
edit- ^ a b c d e van Leeuwen, F. (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 c d e f g h Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b Abt, Helmut A. (January 2009), "MK Classifications of Spectroscopic Binaries", The Astrophysical Journal Supplement, 180 (1): 117–118, Bibcode:2009ApJS..180..117A, doi:10.1088/0067-0049/180/1/117, S2CID 122811461.
- ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ a b c Mayor, M.; Mazeh, T. (January 1987), "The frequency of triple and multiple stellar systems", Astronomy and Astrophysics, 171: 157–177, Bibcode:1987A&A...171..157M.
- ^ a b c d e f g David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ a b Böhm-Vitense, Erika (November 2004), "Rotation and Lithium Surface Abundances, Revisited", The Astronomical Journal, 128 (5): 2435–2442, Bibcode:2004AJ....128.2435B, doi:10.1086/425053..
- ^ "45 Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-07.
- ^ a b Tokovinin, A.; et al. (2008), "Tertiary companions to close spectroscopic binaries", Multiple Stars Across the H-R Diagram, ESO Astrophysics Symposia, vol. 450, Berlin Heidelberg, p. 129, arXiv:astro-ph/0601518, Bibcode:2006A&A...450..681T, doi:10.1051/0004-6361:20054427.