Eta2 Doradus, Latinized from η2 Doradus, is a star in the southern constellation of Dorado. It is visible to the naked eye as a dim, reddish star with an apparent visual magnitude of 5.01[2] It is about 580 light years from the Sun as shown by parallax, and its net movement is one of receding, having a radial velocity of +34.5 km/s.[2] It is circumpolar south of latitude 24° 24′ S.[5]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Dorado |
| Right ascension | 06h 11m 15.0s[1] |
| Declination | −65° 35′ 21.9″[1] |
| Apparent magnitude (V) | 5.01[2] |
| Characteristics | |
| Spectral type | M2.5III[2] |
| B−V color index | 1.599[2] |
| Astrometry | |
| Radial velocity (Rv) | +34.5±0.8[2] km/s |
| Proper motion (μ) | RA: -23.823[1] mas/yr Dec.: +118.639[1] mas/yr |
| Parallax (π) | 5.6046 ± 0.1562 mas[1] |
| Distance | 580 ± 20 ly (178 ± 5 pc) |
| Absolute magnitude (MV) | −1.45[2] |
| Details | |
| Radius | 81.89[1] R☉ |
| Luminosity | 1165[1] L☉ |
| Surface gravity (log g) | 0.403[3] cgs |
| Temperature | 3,726+313 −154[1] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
This object is an M-type giant star, with its stellar classification being M2.5III.[2][6] It has left the main sequence after exhausting its core hydrogen and expanded to around 80 R☉. The star is radiating about 1200[1] times the Sun's luminosity from its photosphere, at an effective temperature of 3726 K.[1]
References
edit- ^ a b c d e f g h i j Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f g h 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.
- ^ McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017). "Fundamental parameters and infrared excesses of Tycho–Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770–791. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. S2CID 73594365.
- ^ "HD 43455". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved September 25, 2008.
- ^ "Circumpolar Calculations | Celestial Observation | Space FM".
- ^ Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1975mcts.book.....H.
External links
edit- 2004. Starry Night Pro, Version 5.8.4. Imaginova. ISBN 978-0-07-333666-4. www.starrynight.com