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]

Eta2 Doradus
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]
Distance580 ± 20 ly
(178 ± 5 pc)
Absolute magnitude (MV)−1.45[2]
Details
Radius81.89[1] R
Luminosity1165[1] L
Surface gravity (log g)0.403[3] cgs
Temperature3,726+313
−154
[1] K
Other designations
η2 Dor, CPD−65°561, FK5 2473, GC 7946, HD 43455, HIP 29353, HR 2245, SAO 249469, PPM 355229, TYC 8901-1098-1[4]
Database references
SIMBADdata

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

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  1. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ "HD 43455". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved September 25, 2008.
  5. ^ "Circumpolar Calculations | Celestial Observation | Space FM".
  6. ^ 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.
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