HD 47475 (HR 2445) is a solitary star located in the southern constellation Columba. With an apparent magnitude of 6.34, its barely visible to the naked eye under ideal conditions. The star is located 1,720 light years away from the Solar System, but is drifting away with a heliocentric radial velocity of 15.77 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Columba |
| Right ascension | 06h 36m 51.27308s[1] |
| Declination | −41° 33′ 25.6990″[1] |
| Apparent magnitude (V) | 6.34±0.01[2] |
| Characteristics | |
| Spectral type | K0 II[3] |
| B−V color index | +1.15[4] |
| Astrometry | |
| Radial velocity (Rv) | 13.8±0.4[5] km/s |
| Proper motion (μ) | RA: +1.235 mas/yr[1] Dec.: +7.745 mas/yr[1] |
| Parallax (π) | 1.835 ± 0.0171 mas[1] |
| Distance | 1,780 ± 20 ly (545 ± 5 pc) |
| Absolute magnitude (MV) | −2.01[6] |
| Details | |
| Mass | 4.0[7] M☉ |
| Radius | 44.8[8] R☉ |
| Luminosity | 1,035[1] L☉ |
| Surface gravity (log g) | 1.66[7] cgs |
| Temperature | 4,845±122[8] K |
| Metallicity [Fe/H] | −0.3[9] dex |
| Rotational velocity (v sin i) | 5.5±2[10] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Properties
editHD 47475 has a classification of K0 II, which states its a bright giant that has exhausted hydrogen at its core and left the main sequence. It has four times the Sun's mass, but has expanded to 45 times the Sun's radius. It radiates at about 1,000 times the Sun's luminosity from its enlarged photosphere from an effective temperature of 4,845 K. HD 47475 has a projected rotational velocity of 5 km/s, which is fast for its class.
References
edit- ^ 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.
- ^ 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.
- ^ Houk, Nancy (1978). Michigan catalogue of two-dimensional spectral types for the HD stars Volume II: Declinations −52° to −41°. Bibcode:1978mcts.book.....H.
- ^ Corben, P. M. (1 January 1966). "Photoelectric magnitudes and colours for bright southern stars". Monthly Notes of the Astronomical Society of South Africa. 25: 44. Bibcode:1966MNSSA..25...44C. ISSN 0024-8266.
- ^ 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.
- ^ a b Anders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardevol, J.; Casamiquela, L.; Figueras, F.; Jimenez-Arranz, O.; Jordi, C.; Monguio, M.; Romero-Gomez, M.; Altamirano, D.; Antoja, T.; Assaad, R.; Cantat-Gaudin, T.; Castro-Ginard, A.; Enke, H.; Girardi, L.; Guiglion, G.; Khan, S.; Luri, X.; Miglio, A.; Minchev, I.; Ramos, P.; Santiago, B. X.; Steinmetz, M. (2022). "VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022)". Vizier Online Data Catalog. Bibcode:2022yCat.1354....0A.
- ^ a b 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.
- ^ Lèbre, A.; de Laverny, P.; do Nascimento Jr., J. D.; De Medeiros, J. R. (19 April 2006). "Lithium abundances and rotational behavior for bright giant stars". Astronomy & Astrophysics. 450 (3): 1173–1179. Bibcode:2006A&A...450.1173L. doi:10.1051/0004-6361:20053485. eISSN 1432-0746. ISSN 0004-6361.
- ^ 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". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. eISSN 1432-0746. ISSN 0004-6361.