Astronomy:Lambda Gruis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Grus |
| Right ascension | 22h 06m 06.88568s[1] |
| Declination | −39° 32′ 36.0659″[1] |
| Apparent magnitude (V) | 4.47[2] |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | K3 III[3] |
| U−B color index | +1.628[2] |
| B−V color index | +1.369[2] |
| Astrometry | |
| Radial velocity (Rv) | +38.80[4] km/s |
| Proper motion (μ) | RA: −23.80[1] mas/yr Dec.: −124.58[1] mas/yr |
| Parallax (π) | 13.47 ± 0.22[1] mas |
| Distance | 242 ± 4 ly (74 ± 1 pc) |
| Absolute magnitude (MV) | +0.12[5] |
| Details[6] | |
| Mass | 2.4 M☉ |
| Radius | 22.3 R☉ |
| Luminosity | 155 L☉ |
| Surface gravity (log g) | 2.13 cgs |
| Temperature | 4,269 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Lambda Gruis, Latinized from λ Gruis, is a solitary,[8] orange-hued star in the southern constellation of Grus. With an apparent visual magnitude of 4.47,[2] it is visible to the naked eye as a faint point of light. The distance to this star, as determined using an annual parallax shift of 13.47 mas as seen from the Earth,[1] is around 242 light years. It is drifting further away with a radial velocity of +39 km/s,[4] having come to within 183 light-years some 805,000 years ago.[5]
This is an evolved K-type giant star with a stellar classification of K3 III,[3] having exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. It has about 2.4 times the mass of the Sun and has expanded to 22.3 times the Sun's radius. The star is radiating 155 times the Sun's luminosity from its photosphere at an effective temperature of 4,269 K.[6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants", Monthly Notices of the Royal Astronomical Society 172 (3): 667–679, doi:10.1093/mnras/172.3.667, Bibcode: 1975MNRAS.172..667J.
- ↑ 3.0 3.1 Houk, N. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
- ↑ 4.0 4.1 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 5.0 5.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 Cruzalèbes, P. et al. (June 2010), "Angular diameter estimation of interferometric calibrators. Example of λ Gruis, calibrator for VLTI-AMBER", Astronomy and Astrophysics 515: 15, doi:10.1051/0004-6361/200913686, A6, Bibcode: 2010A&A...515A...6C.
- ↑ "lam Gru". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=lam+Gru.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
 |  |
