Astronomy:Eta2 Pictoris
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Pictor |
| Right ascension | 05h 04m 58.01433s[1] |
| Declination | −49° 34′ 40.2034″[1] |
| Apparent magnitude (V) | 5.02[2] |
| Characteristics | |
| Spectral type | K5 III[3] |
| U−B color index | +1.82[2] |
| B−V color index | +1.51[2] |
| Variable type | suspected[4] |
| Astrometry | |
| Radial velocity (Rv) | −5.0±7.4[5] km/s |
| Proper motion (μ) | RA: +68.538[1] mas/yr Dec.: −2.186[1] mas/yr |
| Parallax (π) | 7.8033 ± 0.1351[1] mas |
| Distance | 418 ± 7 ly (128 ± 2 pc) |
| Absolute magnitude (MV) | −1.2[6] |
| Details | |
| Radius | 40.56+0.59 −2.38[1] R☉ |
| Luminosity | 362.6±7.4[1] L☉ |
| Temperature | 3,955+121 −28[1] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
η2 Pictoris, Latinised as Eta2 Pictoris, is a solitary[8] star in the southern constellation of Pictor. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.02.[2] With an annual parallax shift of 7.8 mas as seen from the Earth,[1] it is located around 418 light years from the Sun. It is a member of the HR 1614 moving group of stars that share a common motion through space.[6]
This is an evolved K-type giant star with a stellar classification of K5 III,[3] having exhausted the supply of hydrogen at its core, then cooled and expanded off the main sequence. At present it has 41[1] times the girth of the Sun. It is radiating an estimated 363.5 times the Sun's luminosity from its photosphere at an effective temperature of 4,136 K.[9] This is a member of the old disk population and is a suspected variable star.[10]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Cousins, A. W. J. et al. (1969), "Comparison Stars for Long Period Variables", Monthly Notes of the Astronomical Society of Southern Africa 28: 63, Bibcode: 1969MNSSA..28...63C.
- ↑ 3.0 3.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Department of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
- ↑ Samus, N. N. et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1: B/gcvs. Bibcode: 2009yCat....102025S.
- ↑ 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, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ 6.0 6.1 Eggen, Olin J. (October 1996), "Star Streams and Galactic Structure", Astronomical Journal 112: 1595, doi:10.1086/118126, Bibcode: 1996AJ....112.1595E.
- ↑ "* eta02 Pic". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+eta02+Pic.
- ↑ 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.
- ↑ McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
- ↑ Eggen, O. J. (1973), "The classification of intrinsic variables. IV. Very-small-amplitude, very-short-period red variables", Astrophysical Journal 184: 793, doi:10.1086/152371, Bibcode: 1973ApJ...184..793E.
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