9 Aurigae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 06m 40.62967s[1] |
| Declination | +51° 35′ 51.8025″[1] |
| Apparent magnitude (V) | 4.93 - 5.03[2] |
| Characteristics | |
| Spectral type | F2V[3] |
| U−B color index | -0.03[4] |
| B−V color index | +0.34[4] |
| Variable type | γ Dor[5] |
| Astrometry | |
| Radial velocity (Rv) | -0.90 ± 0.3[6] km/s |
| Proper motion (μ) | RA: -30.49[1] mas/yr Dec.: -172.89[1] mas/yr |
| Parallax (π) | 38.04 ± 0.34[1] mas |
| Distance | 85.7 ± 0.8 ly (26.3 ± 0.2 pc) |
| Details[5] | |
| Radius | 1.56 R☉ |
| Surface gravity (log g) | 4.07 cgs |
| Temperature | 7023 K |
| Rotational velocity (v sin i) | 21.0 km/s |
| Other designations | |
| Database references | |
| SIMBAD | 9 Aur |
| 9 Aur A | |
| 9 Aur B | |
9 Aurigae (9 Aur) is a star in the constellation Auriga. It has an apparent magnitude of about 5, making it visible to the naked eye in bright suburban skies.[7] Parallax estimates made by the Hipparcos spacecraft put it at a distance of about 85.7 light-years, or 26.3 parsecs.[1]
9 Aurigae is a well-studied Gamma Doradus variable,[5] and was in fact one of the first stars to be classified as one.[8] These types of stars vary in luminosity due to non-radial pulsations.[8] 9 Aurigae's apparent magnitude varies from 4.93 to 5.03 over a period of 1.25804 days.[2] For that reason it has been given the variable star designation V398 Aurigae.[2]
9 Aurigae is a triple star system. The central pair of stars form a spectroscopic binary with a period of 391.7 days and an eccentricity of 0.37.[9] Light from only the primary star can be detected,[9] so it is considered to be single-lined. It also has a red dwarf companion separated 5″ from the main star.[5]
References
- 1 2 3 4 5 6 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.
- 1 2 3 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. Bibcode:2009yCat....1.2025S.
- ↑ Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc--The Southern Sample". The Astronomical Journal. 132: 161. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637.
- 1 2 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV data. Bibcode:1986EgUBV........0M.
- 1 2 3 4 Rachford, Brian L.; Foight, Dillon R. (2009). "Chromospheric Variability in Early F-Type Stars". The Astrophysical Journal. 698: 786. arXiv:0904.1620. Bibcode:2009ApJ...698..786R. doi:10.1088/0004-637X/698/1/786.
- ↑ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
- ↑ Bortle, John E. (February 2001). "The Bortle Dark-Sky Scale". Sky & Telescope. Sky Publishing Corporation. Retrieved 15 May 2017.
- 1 2 Krisciunas, K.; Griffin, R. F.; Guinan, E. F.; Luedeke, K. D.; McCook, G. P. (1995). "9 Aurigae: Strong evidence for non-radial pulsations". Monthly Notices of the Royal Astronomical Society. 273 (3): 662. arXiv:astro-ph/9407094. Bibcode:1995MNRAS.273..662K. doi:10.1093/mnras/273.3.662.
- 1 2 Pourbaix, D.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213.