Pi Tauri
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 26m 36.37093s |
| Declination | +14° 42′ 49.6126″ |
| Apparent magnitude (V) | +4.69 |
| Characteristics | |
| Evolutionary stage | horizontal branch |
| Spectral type | G7 IIIa Fe-1 |
| U−B color index | +0.72 |
| B−V color index | +0.98 |
| Astrometry | |
| Radial velocity (Rv) | +31.4±0.3 km/s |
| Proper motion (μ) | RA: −9.52 mas/yr Dec.: −31.44 mas/yr |
| Parallax (π) | 7.83±0.22 mas |
| Distance | 420 ± 10 ly (128 ± 4 pc) |
| Absolute magnitude (MV) | −0.84 |
| Details | |
| Mass | 4.4 M☉ |
| Radius | 22 R☉ |
| Luminosity | 244 L☉ |
| Surface gravity (log g) | 2.39 cgs |
| Metallicity [Fe/H] | −0.08 dex |
| Rotational velocity (v sin i) | 7.1 km/s |
| Age | 554 Myr |
| Other designations | |
| π Tau, 73 Tau, BD+14°697, HD 28100, HIP 20732, HR 1396, SAO 93935 | |
| Database references | |
| SIMBAD | data |
Pi Tauri (π Tauri) is a solitary, yellow-hued star in the zodiac constellation of Taurus. With an apparent visual magnitude of +4.69, it is bright enough to be visible to the naked eye. Although it appears to lie among the stars of the Hyades cluster, it is not itself a member, being three times farther from Earth than the cluster. The distance to this star, as determined using an annual parallax shift of 7.83 mas as seen from the Earth, is around 420 light years. At that range, the visual magnitude of the star is diminished by extinction of 0.24 magnitudes due to interstellar dust.
This is an evolved G-type giant star with a stellar classification of G7 IIIa Fe-1, where the suffix notation indicates an underabundance of iron in the spectrum. The measured angular diameter is 1.55±0.06 mas. At the estimated distance of Pi Tauri, this yields a physical size of about 22 times the radius of the Sun. It possesses 4.4 times the mass of the Sun and is radiating 244 times the Sun's luminosity at an effective temperature of 5006 K.
References
- 1 2 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. XHIP record for this object at VizieR.
- 1 2 3 4 5 6 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.
- 1 2 3 4 Argue, A. N. (1966), "UBV photometry of 550 F, G and K type stars", Monthly Notices of the Royal Astronomical Society, 133 (4): 475–493, Bibcode:1966MNRAS.133..475A, doi:10.1093/mnras/133.4.475.
- ↑ Stock, Stephan; Reffert, Sabine; Quirrenbach, Andreas (2018). "Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search". Astronomy and Astrophysics. 616: A33. arXiv:1805.04094. Bibcode:2018A&A...616A..33S. doi:10.1051/0004-6361/201833111.
- 1 2 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
- ↑ 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.
- 1 2 3 4 Van Belle, Gerard T.; von Braun, Kaspar; Ciardi, David R.; Pilyavsky, Genady; Buckingham, Ryan S.; Boden, Andrew F.; Clark, Catherine A.; Hartman, Zachary; Van Belle, Gerald; Bucknew, William; Cole, Gary (2021). "Direct Measurements of Giant Star Effective Temperatures and Linear Radii: Calibration against Spectral Types and V - K Color". The Astrophysical Journal. 922 (2): 163. arXiv:2107.09205. Bibcode:2021ApJ...922..163V. doi:10.3847/1538-4357/ac1687.
- 1 2 Yu, Jie; Khanna, Shourya; Themessl, Nathalie; Hekker, Saskia; Dréau, Guillaume; Gizon, Laurent; Bi, Shaolan (2023). "Revised Extinctions and Radii for 1.5 Million Stars Observed by APOGEE, GALAH, and RAVE". The Astrophysical Journal Supplement Series. 264 (2): 41. arXiv:2206.00046. Bibcode:2023ApJS..264...41Y. doi:10.3847/1538-4365/acabc8.
- 1 2 3 4 Das, Pradosh Barun; Zucker, Daniel B.; De Silva, Gayandhi M.; Borsato, Nicholas W.; Mura-Guzmán, Aldo; Buder, Sven; Ness, Melissa; Nordlander, Thomas; Casey, Andrew R.; Martell, Sarah L.; Bland-Hawthorn, Joss; De Grijs, Richard; Freeman, Ken C.; Kos, Janez; Stello, Dennis; Lewis, Geraint F.; Hayden, Michael R.; Sharma, Sanjib (2025). "The GALAH Survey: Stellar parameters and abundances for 800 000 Gaia RVS spectra using GALAH DR4 and the Cannon". Monthly Notices of the Royal Astronomical Society. 538 (2): 605. arXiv:2410.12272. Bibcode:2025MNRAS.538..605D. doi:10.1093/mnras/staf169.
- ↑ Ting, Yuan-Sen; Rix, Hans-Walter (2019). "The Vertical Motion History of Disk Stars throughout the Galaxy". The Astrophysical Journal. 878 (1): 21. arXiv:1808.03278. Bibcode:2019ApJ...878...21T. doi:10.3847/1538-4357/ab1ea5.
- ↑ "pi Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-30.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ↑ Takeda, Yoichi; et al. (August 2008), "Stellar Parameters and Elemental Abundances of Late-G Giants", Publications of the Astronomical Society of Japan, 60 (4): 781–802, arXiv:0805.2434, Bibcode:2008PASJ...60..781T, doi:10.1093/pasj/60.4.781.
- ↑ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
