36 G. Doradus (HD 40409) is a suspected astrometric binary[7] star system in the southern constellation of Dorado. It is a faint system but visible to the naked eye with an apparent visual magnitude of 4.65.[2] Based upon an annual parallax shift of 36.60 mas,[1] it is located 89 light years away from the Sun. It is moving further away with a heliocentric radial velocity of +25 km/s.[2] The system has a relatively high proper motion, traversing the celestial sphere at the rate of 0.57 arcseconds per year along a position angle of 14.51°.[8]

36 G. Doradus
Observation data
Epoch J2000      Equinox J2000
Constellation Dorado
Right ascension 05h 54m 06.05459s[1]
Declination −63° 05′ 23.2090″[1]
Apparent magnitude (V) 4.65[2]
Characteristics
Spectral type K2 III[3]
B−V color index 1.022±0.045[2]
Astrometry
Radial velocity (Rv)+25.1±0.8[2] km/s
Proper motion (μ) RA: +148.129 mas/yr[1]
Dec.: +550.143 mas/yr[1]
Parallax (π)36.5981 ± 0.0924 mas[1]
Distance89.1 ± 0.2 ly
(27.32 ± 0.07 pc)
Absolute magnitude (MV)2.56[2]
Details[4]
Mass1.07±0.08 M
Radius4.76±0.14 R
Luminosity10.9±0.3 L
Surface gravity (log g)3.020±0.155 cgs
Temperature4,807±62 K
Metallicity [Fe/H]+0.141±0.035 dex
Age7.91[5] Gyr
Other designations
CD−63°218, FK5 2452, GJ 9194, HD 40409, HIP 27890, HR 2102, SAO 249390[6]
Database references
SIMBADdata

Based on the stellar classification of K2 III assigned by Gray et al. (2006),[3] the visible component is a K-type giant star. In contrast, Keenan and McNeil (1989) gave it a somewhat less evolved classification of K2 III–IV.[9] It is about eight billion years old[5] with 7% more mass than the Sun, and has expanded to 4.76 times the Sun's radius. The star is radiating 11 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,807 K.[4]

References

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  1. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c d e f 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. ^ a b Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
  4. ^ a b Ottoni, G.; Udry, S.; Ségransan, D.; Buldgen, G.; Lovis, C.; Eggenberger, P.; Pezzotti, C.; Adibekyan, V.; Marmier, M.; Mayor, M.; Santos, N. C.; Sousa, S. G.; Lagarde, N.; Charbonnel, C. (2022-01-01). "CORALIE radial-velocity search for companions around evolved stars (CASCADES). I. Sample definition and first results: Three new planets orbiting giant stars". Astronomy and Astrophysics. 657: A87. arXiv:2201.01528. Bibcode:2022A&A...657A..87O. doi:10.1051/0004-6361/202040078. ISSN 0004-6361. 36 G. Doradus' database entry at VizieR.
  5. ^ a b Wittenmyer, Robert A.; Liu, Fan; Wang, Liang; Casagrande, Luca; Johnson, John Asher; Tinney, C. G. (July 2016), "The Pan-Pacific Planet Search. V. Fundamental Parameters for 164 Evolved Stars", The Astronomical Journal, 152 (1): 15, arXiv:1605.00323, Bibcode:2016AJ....152...19W, doi:10.3847/0004-6256/152/1/19, S2CID 55991800, 19.
  6. ^ "HD 40409". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-16.
  7. ^ 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, S2CID 14878976.
  8. ^ Bakos, Gáspár Á.; et al. (July 2002), "Revised Coordinates and Proper Motions of the Stars in the Luyten Half-Second Catalog", The Astrophysical Journal Supplement Series, 141 (1): 187–193, arXiv:astro-ph/0202164, Bibcode:2002ApJS..141..187B, doi:10.1086/340115, S2CID 36667868.
  9. ^ Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.