Location of G Doradus on the map (circled) | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Dorado |
| Right ascension | 05 32 59.56572 |
| Declination | −64° 13′ 39.0537″ |
| Apparent magnitude (V) | 5.34±0.01 |
| Characteristics | |
| Spectral type | G8/K0 III |
| U−B color index | +0.85 |
| B−V color index | +1.04 |
| Astrometry | |
| Radial velocity (Rv) | 9.8±2.8 km/s |
| Proper motion (μ) | RA: +45.741 mas/yr Dec.: −3.051 mas/yr |
| Parallax (π) | 13.9330 ± 0.2335 mas |
| Distance | 234 ± 4 ly (72 ± 1 pc) |
| Absolute magnitude (MV) | +1.08 |
| Orbit | |
| Period (P) | 180.8757 d |
| Semi-major axis (a) | 0.320 AU |
| Eccentricity (e) | 0.509±0.010 |
| Inclination (i) | 52.2±5.2° |
| Longitude of the node (Ω) | 45.4±6.6° |
| Periastron epoch (T) | 2,423,108.42±0.65 JD |
| Argument of periastron (ω) (secondary) | 332.93±1.61° |
| Semi-amplitude (K1) (primary) | 22.36±0.35 km/s |
| Details | |
| A | |
| Mass | 3.47 M☉ |
| Radius | 10.5 −0.2 R☉ |
| Luminosity | 48.4 −1.5 L☉ |
| Surface gravity (log g) | 2.61 cgs |
| Temperature | 4819±123 K |
| Metallicity | −0.20 dex |
| Rotational velocity (v sin i) | <1.0 km/s |
| Age | 556 −188 Myr |
| B | |
| Mass | 1.87 M☉ |
| Other designations | |
| G Dor, 28 G. Doradus[14], CPD−64°456, FK5 2418, GC 6927, HD 37297, HIP 26001, HR 1917, SAO 249309, TIC 149304313 | |
| Database references | |
| SIMBAD | data |
G Doradus (HD 37297; HR 1917; 28 G. Doradus) is a spectroscopic binary located in the southern constellation Dorado, the dolphinfish. It has an apparent magnitude of 5.34, making it faintly visible to the naked eye under ideal conditions. The system is located relatively close at a distance of 234 light-years based on Gaia DR3 parallax measurements but it is receding with a heliocentric radial velocity of approximately 9.8 km/s. At its current distance, G Doradus' brightness is diminished by a quarter of a magnitude due to interstellar extinction and it has an absolute magnitude of +1.08. The bayer designation "G Doradus" was not assigned by Benjamin Gould or Lacaille. It merely arose due to the designation assigned by Gould; 28 G. Doradus.
The visible component has a stellar classification of G8/K0 III, indicating that it is an evolved star with the characteristics of a G8 and K0 giant star. It has 3.47 times the mass of the Sun but at the age of 556 million years, it has expanded to 10.5 times the radius of the Sun. It radiates 48.4 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,819 K, giving it an orangish-yellow hue when viewed in the night sky. G Doradus is slightly metal deficient with an iron abundance of = −0.20 and it spins too slowly for its projected rotational velocity to be measured accurately.
G Doradus is a single-lined spectroscopic binary; the components – which have a separation of 0.32 AU – take 181 days to circle each other in an elliptical orbit, but the orbit is not well constrained. Although only the primary can be observed in the spectrum, the masses of both components can be determined. Krachieva et al. (1980) derives a mass of 1.87 M☉ for the companion, which might be an A-type star.
References
- ^ 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.
- ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361. S2CID 17128864.
- ^ Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars: Declinations −90° to −53°. Vol. 1. Bibcode:1975mcts.book.....H.
- ^ Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.
- ^ Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
- ^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
- ^ Lunt, Joseph (1924). "On the orbits of the seven spectroscopic-binary stars : ί Gruis, θ Crucis, 28 Doradus, α Phoenicis, β Doradus, W Velorum, ρ Tucanae". Annals of the Cape Observatory. 10: 7. Bibcode:1924AnCap..10....7L.
- ^ Jancart, S.; Jorissen, A.; Babusiaux, C.; Pourbaix, D. (September 30, 2005). "Astrometric orbits of SB stars". Astronomy & Astrophysics. 442 (1). EDP Sciences: 365–380. arXiv:astro-ph/0507695. Bibcode:2005A&A...442..365J. doi:10.1051/0004-6361:20053003. ISSN 0004-6361. S2CID 55637839.
- ^ Kraicheva, Z.; Popova, E.; Tutukov, A.; Yungelson, L. (July 1980). "Catalogue of physical parameters of spectroscopic binary stars". Bull. Inf. Centre Données Stellaires. 19: 71. Bibcode:1980BICDS..19...71K. S2CID 118298938.
- Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. eISSN 1432-0746. ISSN 0004-6361. S2CID 131780028.
- ^ Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.
- ^ Eggen, Olin J. (January 1989). "Large and Kinematically Unbiased Samples of G- and K-Type Stars. III. Evolved Young Disk Stars in the Bright Star Sample". Publications of the Astronomical Society of the Pacific. 101: 54. Bibcode:1989PASP..101...54E. doi:10.1086/132404. eISSN 1538-3873. ISSN 0004-6280. S2CID 122928361.
- ^ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars V: Southern stars *". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. eISSN 1432-0746. ISSN 0004-6361. S2CID 54046583.
- Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
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- Wagman, Morton (2003). Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others. Blacksburg, VA: The McDonald & Woodward Publishing Company. p. 137. ISBN 978-0-939923-78-6.
