| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 23m 51.82553s1 |
| Declination | +09° 27′ 39.4939″1 |
| Apparent magnitude (V) | 5.0982 (5.8 / 5.9)3 |
| Characteristics | |
| Spectral type | A3V + A4V4 |
| U−B color index | +0.105 |
| B−V color index | +0.075 |
| Astrometry | |
| Radial velocity (Rv) | −8.70±16 km/s |
| Proper motion (μ) | RA: −20.321 mas/yr Dec.: −5.321 mas/yr |
| Parallax (π) | 8.24±0.31 mas1 |
| Distance | 400 ± 10 ly (121 ± 5 pc) |
| Absolute magnitude (MV) | −0.327 |
| Orbit3 | |
| Period (P) | 54.77 yr |
| Semi-major axis (a) | 0.188″ |
| Eccentricity (e) | 0.720 |
| Inclination (i) | 34.2° |
| Longitude of the node (Ω) | 239.8° |
| Periastron epoch (T) | 1937.24 |
| Argument of periastron (ω) (secondary) | 332.0° |
| Details | |
| 66 Tau A | |
| Mass | 2.898note 1 M☉ |
| Rotational velocity (v sin i) | 819 km/s |
| 66 Tau B | |
| Mass | 2.768note 1 M☉ |
| Other designations | |
| r Tau, BD+09°570, HD 27820, HIP 20522, HR 1381, SAO 111791 | |
| Database references | |
| SIMBAD | data |
66 Tauri, also known as r Tauri, is a binary star in the constellation of Taurus. The combined apparent magnitude of the system is 5.098,2 with the magnitudes of the two components being 5.8 and 5.9, respectively.3 Parallax measurements by Hipparcos put 66 Tauri at some 400 light-years (121 parsecs) away.1
This is a visual binary where the positions of the two stars are tracked over time, and used to calculate an orbit. The two stars orbit each other every 55 years.3 Their orbit is fairly eccentric, at 0.720, and the two stars are separated by 0.188″ on average.3 Both stars are A-type main-sequence stars with similar masses.8
Notes
Notes
- Cvetkovic et al. gives two possible mass sums: 2.89 / 2.76 M☉ or 2.88 / 2.77 M☉.
References
References
- 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.
- 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.
- "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 1 August 2017. Retrieved 13 August 2017.
- Christy, James W.; Walker, R. L. Jr. (1969). "MK Classification of 142 Visual Binaries". Publications of the Astronomical Society of the Pacific. 81 (482): 643. Bibcode:1969PASP...81..643C. doi:10.1086/128831.
- Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- 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. S2CID 119231169.
- 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.
- Cvetkovic, Z.; Ninkovic, S. (2010). "On the Component Masses of Visual Binaries". Serbian Astronomical Journal. 180 (180): 71–80. Bibcode:2010SerAJ.180...71C. doi:10.2298/SAJ1080071C.
- Royer, F.; Zorec, J.; Gómez, A. E. (2007). "Rotational velocities of A-type stars". Astronomy and Astrophysics. 463 (2): 671. arXiv:astro-ph/0610785. Bibcode:2007A&A...463..671R. doi:10.1051/0004-6361:20065224. S2CID 18475298.