Lambda2 Tucanae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Tucana |
| Right ascension | 00h 55m 00.31170s[1] |
| Declination | −69° 31′ 37.5057″[1] |
| Apparent magnitude (V) | +5.45[2] |
| Characteristics | |
| Spectral type | K2 III[3] |
| B−V color index | +1.10[2] |
| Astrometry | |
| Radial velocity (Rv) | +5.1±2.8[4] km/s |
| Proper motion (μ) | RA: +7.37[1] mas/yr Dec.: −43.69[1] mas/yr |
| Parallax (π) | 14.70 ± 0.27[1] mas |
| Distance | 222 ± 4 ly (68 ± 1 pc) |
| Absolute magnitude (MV) | +1.29[5] |
| Details[2] | |
| Mass | 1.75 M☉ |
| Radius | 8.940 R☉ |
| Luminosity | 37 L☉ |
| Surface gravity (log g) | 2.74 cgs |
| Temperature | 4,780 K |
| Metallicity [Fe/H] | −0.07±0.14 dex |
| Rotational velocity (v sin i) | 3.14 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Lambda2 Tucanae is a solitary[7] star in the southern constellation of Tucana. It is faintly visible to the naked eye with an apparent visual magnitude of +5.45.[2] Based upon an annual parallax shift of 14.70 mas as seen from Earth, it is located around 222 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.09 due to interstellar dust.[2]
This is an orange-hued K-type giant star on the red giant branch,[2] with a stellar classification of K2 III.[3] It has an estimated 1.75 times the mass of the Sun but after evolving away from the main sequence it has expanded to 8.9 times the Sun's radius. The star is radiating 37 times the solar luminosity from its photosphere at an effective temperature of 4,780 K.[2]
References
- 1 2 3 4 5 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.
- 1 2 3 4 5 6 7 Jones, M. I.; et al. (December 2011), "Study of the impact of the post-MS evolution of the host star on the orbits of close-in planets. I. Sample definition and physical properties", Astronomy & Astrophysics, 536: 7, arXiv:1110.6459, Bibcode:2011A&A...536A..71J, doi:10.1051/0004-6361/201117887, A71.
- 1 2 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- ↑ 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, A61.
- ↑ 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.
- ↑ "lam Tuc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-04-21.
- ↑ 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.