HD 47500

HD 47500

Observation data Epoch J2000      Equinox J2000
Constellation	Columba
A
Right ascension	06^h 37^m 13.84^s[1]
Declination	−36° 59′ 26.37″[1]
Apparent magnitude (V)	5.91±0.01[1]
B
Right ascension	06^h 37^m 13.84^s[1]
Declination	−36° 59′ 25.91″[1]
Apparent magnitude (V)	7.51±0.01[1]
Characteristics
A
Evolutionary stage	main sequence[2]
Spectral type	B6 IV-V[3]
U−B color index	−0.52[4]
B−V color index	−0.12[4]
Astrometry
Radial velocity (Rv)	21±4[5] km/s
Proper motion (μ)	RA: −9.053 mas/yr[6] Dec.: +11.625 mas/yr[6]
Parallax (π)	2.9218 ± 0.2076 mas[6]
Distance	1,120 ± 80 ly (340 ± 20 pc)
Absolute magnitude (MV)	−1.93[7]
Details
A
Mass	5.01±0.05[8] M☉
Radius	7.33[9] R☉
Luminosity	1,482+665 −459[2] L☉
Surface gravity (log g)	3.61[10] cgs
Temperature	14,703±290[11] K
Metallicity [Fe/H]	−0.07[10] dex
Rotational velocity (v sin i)	36[12] km/s
Age	34±1[2] Myr
Other designations
112 G. Columbae[13], CD−36°3031, CPD−36°1014, GC 8658, HD 47500, HIP 31637, HR 2446, SAO 197014, WDS J06372-3659AB[14]
Database references
SIMBAD	The system
	A
	B

HD 47500, also known as HR 2446, is a binary star^[15] in the southern constellation Columba. The primary has an apparent magnitude of 5.91,^[1] making it faintly visible to the naked eye if viewed under ideal conditions. As for the companion, its visual magnitude is 7.51.^[1] The system is located relatively far at a distance of 1,120 light years based on parallax measurements,^[6] and is receding with a heliocentric radial velocity of 21 km/s.^[5]

The binary nature of this system was first discovered by Richard Alfred Rossiter in 1942.^[16] Their current separation is half of an arcsecond, making it difficult to measure the components properties. Nevertheless, the secondary component is located along a position angle of 4° as of 1999.^[17]

HD 47500 has a stellar classification of B6 IV-V,^[3] a B-type star with a luminosity class intermediate between a subgiant and main sequence star. Hube (1970) gave the primary a slightly cooler class of B7 III,^[18] indicating that it is already a giant star, while Houk (1982) gave it a class of B5/7 IV,^[19] intermediate between a B5 and B7 subgiant. Nevertheless, it is estimated to be 34 million years old, having completed 98.5% of its main sequence lifetime.^[2] HD 47500 A has 5.01 times the mass of the Sun^[8] and an enlarged radius of 7.33 R_☉.^[9] It radiates 1,482 times the luminosity of the Sun.^[2] from its photosphere at an effective temperature of 14,703 K,^[11] giving it a bluish-white hue. Unlike most hot stars, the object spins modestly with a projected rotational velocity of 36 km/s.^[12]

References

1. Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (March 2002). "The Tycho double star catalogue". Astronomy & Astrophysics. 384 (1): 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822. eISSN 1432-0746. ISSN 0004-6361.
2. Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars". Astronomy & Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. eISSN 1432-0746. ISSN 0004-6361.
3. Oblak, E.; Chareton, M. (September 1981). "On the Estimation of Photometric Spectral Types". Astronomy and Astrophysics Supplement Series. 45: 459. Bibcode:1981A&AS...45..459O. ISSN 0365-0138.
4. Deutschman, W. A.; Davis, R. J.; Schild, R. E. (February 1976). "The galactic distribution of interstellar absorption as determined from the Celescope catalog of ultraviolet stellar observations and a new catalog of UBV, H-β photoelectric observations". The Astrophysical Journal Supplement Series. 30: 97. Bibcode:1976ApJS...30...97D. doi:10.1086/190359. eISSN 1538-4365. ISSN 0067-0049.
5. Kharchenko, N.V.; Scholz, R.-D.; Piskunov, A.E.; Röser, S.; Schilbach, E. (November 2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889–896. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. eISSN 1521-3994. ISSN 0004-6337. S2CID 119323941.
6. 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.
7. 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.
8. Hohle, M.M.; Neuhäuser, R.; Schutz, B.F. (April 2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten. 331 (4): 349–360. arXiv:1003.2335. Bibcode:2010AN....331..349H. doi:10.1002/asna.200911355. eISSN 1521-3994. ISSN 0004-6337. S2CID 111387483.
9. Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. eISSN 1432-0746. ISSN 0004-6361.
10. 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.
11. Paunzen, E.; Schnell, A.; Maitzen, H. M. (December 2005). "An empirical temperature calibration for the Δa photometric system I: The B-type stars". Astronomy & Astrophysics. 444 (3): 941–946. arXiv:astro-ph/0509049. Bibcode:2005A&A...444..941P. doi:10.1051/0004-6361:20053546. eISSN 1432-0746. ISSN 0004-6361.
12. Levato, H.; Grosso, M. (June 2004). "New Projected Rotational Velocities of All Southern B-type Stars of the Bright Star Catalogue". Astronomical Society of the Pacific. 215: 51. Bibcode:2004IAUS..215...51L.
13. 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.
14. "HD 47500". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 14, 2022.
15. Eggleton, P. P.; Tokovinin, A. A. (11 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. eISSN 1365-2966. ISSN 0035-8711.
16. Rossiter, Richard Alfred (1943). "Fourth list of new southern double stars found at the Lamont-Hussey Observatory of the University of Michigan, at Bloemfontein, Orange Free State, South Africa". Publications of Michigan Observatory. 8 (10): 133–140. Bibcode:1943POMic...8..133R.
17. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.
18. Hube, Douglas P. (1970). "The radial velocities of 335 late B-type stars". Memoirs of the Royal Astronomical Society. 72: 233. Bibcode:1970MmRAS..72..233H.
19. Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Volume_3. Declinations −40° to −26°. Bibcode:1982mcts.book.....H.