HD 47475

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HD 47475
Observation data
Epoch J2000      Equinox J2000
Constellation Columba
Right ascension 06h 36m 51.27s[1]
Declination −41° 33′ 25.7″[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)15.77±0.17[1] km/s
Proper motion (μ) RA: +1.285[1] mas/yr
Dec.: +7.693[1] mas/yr
Parallax (π)1.8945 ± 0.0203[1] mas
Distance1,720 ± 20 ly
(528 ± 6 pc)
Absolute magnitude (MV)-2.01[5]
Details
Mass4.04±0.57[6] M☉
Radius45.96+1.62
−1.31[1] R☉
Luminosity943±19[1] L☉
Surface gravity (log g)1.79[7] cgs
Temperature4,718+69
−81[1] K
Metallicity [Fe/H]-0.23[7] dex
Rotational velocity (v sin i)5±2[8] km/s
Other designations
111 G. Columbae, CD−41 2488, HD 47475, HIP 31063, HR 2445, SAO 218060
Database references
SIMBADdata

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.

Properties[]

HD 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 4.04 times the Sun's mass, but has expanded to 46 times the Sun's radius. It radiates at 943 times the Sun's luminosity from its enlarged photosphere from an effective temperature of 4,718 K. HD 47475 has a projected rotational velocity of 5 km/s, which is fast for its class. Hohle et al. suggests that HD 47475 was once a B-type main-sequence star.[6]

References[]

  1. ^ a b c d e f g h 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. ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (1 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.
  3. ^ Houk, Nancy (1 January 1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Bibcode:1978mcts.book.....H.
  4. ^ 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.
  5. ^ Anderson, E.; Francis, Ch. (1 May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. ISSN 1063-7737. S2CID 119257644.
  6. ^ a b Hohle, M. M.; Neuhäuser, R.; Schutz, B. F. (1 April 2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten. 331 (4): 349–360. Bibcode:2010AN....331..349H. doi:10.1002/asna.200911355. ISSN 0004-6337. S2CID 111387483.
  7. ^ a b Anders, F.; et al. (1 August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. ISSN 0004-6361. S2CID 131780028.
  8. ^ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (1 January 2014). "A catalog of rotational and radial velocities for evolved stars. V. Southern stars". Astronomy and Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. ISSN 0004-6361. S2CID 54046583.
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