Pi Aurigae
| |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 59m 56.0994s[1] |
| Declination | +45° 56′ 12.248″[1] |
| Apparent magnitude (V) | 4.25[2] |
| Characteristics | |
| Spectral type | M3 II[3] |
| U−B color index | +1.83[2] |
| B−V color index | +1.72[2] |
| R−I color index | 1.48 |
| Variable type | LC[4] |
| Astrometry | |
| Radial velocity (Rv) | 0.71 ± 0.76[5] km/s |
| Proper motion (μ) | RA: -2.42[1] mas/yr Dec.: -7.32[1] mas/yr |
| Parallax (π) | 3.88 ± 0.85[1] mas |
| Distance | approx. 800 ly (approx. 260 pc) |
| Details | |
| Mass | 5.0 M☉ |
| Radius | 265[6] R☉ |
| Luminosity | 9590 L☉ |
| Temperature | 3530 K |
| Age | 70-100 Myr |
| Other designations | |
Pi Aurigae (π Aur, π Aurigae) is the Bayer designation for a star in the northern constellation of Auriga. Located about one degree north of the 2nd magnitude star Beta Aurigae,[8] Pi Aurigae is visible to the naked eye with an apparent visual magnitude of 4.25[2] Based upon parallax measurements, it is approximately 800 light-years (250 parsecs) away from Earth.[1] At that distance, the brightness of the star is diminished by 0.54 in magnitude from extinction caused by interstellar gas and dust.[5]
Pi Aurigae is a bright giant star with a stellar classification of M3 II.[3] The measured angular diameter of this star, after correction for limb darkening, is 9.56 ± 0.10 mas.[9] At the estimated distance of Pi Aurigae,[1] this yields a physical size of about 265 times the radius of the Sun.[6] It is classified as an slow irregular variable of type LC and its brightness varies from magnitude +4.24 to +4.34.[4]
References
- 1 2 3 4 5 6 7 van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1
, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. Note: see VizieR catalogue I/311. - 1 2 3 4 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J.
- 1 2 Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics, 11: 29, Bibcode:1973ARA&A..11...29M, doi:10.1146/annurev.aa.11.090173.000333.
- 1 2 Ruban, E. V.; et al. (September 2006), "Spectrophotometric observations of variable stars", Astronomy Letters, 32 (9): 604–607, Bibcode:2006AstL...32..604R, doi:10.1134/S1063773706090052.
- 1 2 Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272.
- 1 2 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
- ↑ "pi. Aur -- Pulsating variable Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-08-20.
- ↑ O'Meara, Stephen James (2007), Steve O'Meara's Herschel 400 Observing Guide, Cambridge University Press, p. 23, ISBN 0521858933.
- ↑ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431: 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
