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10 Canis Majoris

A light curve for FT Canis Majoris from Hipparcos data, adapted from Lefèvre et al. (2009)
Observation data Epoch J2000      Equinox J2000
Constellation	Canis Major
Right ascension	06 44 28.46710
Declination	−31° 04′ 13.8923″
Apparent magnitude (V)	5.23 (5.13–5.44)
Characteristics
Spectral type	B2 V or B2 IIIe
B−V color index	−0.127±0.005
Variable type	Be
Astrometry
Radial velocity (Rv)	+34.0±4.2 km/s
Proper motion (μ)	RA: −3.286 mas/yr Dec.: +4.201 mas/yr
Parallax (π)	1.6454 ± 0.0722 mas
Distance	1,980 ± 90 ly (610 ± 30 pc)
Details
Mass	19.2±0.1 M☉
Radius	10.0 R☉
Luminosity	44,463+35,336 −19,689 L☉
Surface gravity (log g)	3.76±0.17 cgs
Temperature	25,350±1,030 K
Rotation	2.63 d
Rotational velocity (v sin i)	205±5 km/s
Age	8.2±0.1 Myr
Other designations
10 CMa, FT Canis Majoris, CD−30°3484, GC 8827, HD 48917, HIP 32292, HR 2492, SAO 197149, CCDM 06445-3104, WDS J06445-3104
Database references
SIMBAD	data

10 Canis Majoris is a single variable star in the southern constellation of Canis Major, located roughly 1,980 light years away from the Sun. It has the variable star designation FT Canis Majoris; 10 Canis Majoris is the Flamsteed designation. This body is visible to the naked eye as a faint, blue-white hued star with a baseline apparent visual magnitude of 5.23. It is moving away from the Earth with a heliocentric radial velocity of +34 km/s.

This is a massive Be star with a stellar classification of B2 V, matching a B-type main-sequence star. Hiltner et al. (1969) found a giant class of B2 IIIe, which is still in use with some studies. The star is spinning rapidly with a projected rotational velocity of 205 km/s and a rotational period of 2.63 days. This is giving it an oblate shape with an equatorial bulge that is 5% larger than the polar radius. The axis of rotation is inclined by an angle of 45° to the line of sight from the Earth.

In 1968, Alejandro Feinstein announced that the star is variable, based on observations from 1963-1965. It was given its variable star designation in 1973. Samus et al. (2017) classify it as a Be-type variable star that ranges from a peak visual magnitude of 5.13 down to 5.44 with a rotationally-modulated period of 2.63 days.

10 Canis Majoris is 8.2 million years old with 19.2 times the mass of the Sun and 10 times the Sun's radius. It is radiating around 44,000 times the luminosity of the Sun from its photosphere at an effective temperature of 25,000 K. There is a magnitude 12.58 visual companion at an angular separation of 37.3″ along a position angle of 99°, as of 2015.

References

1. Lefèvre, L.; Marchenko, S. V.; Moffat, A. F. J.; Acker, A. (November 2009), "A systematic study of variability among OB-stars based on HIPPARCOS photometry", Astronomy & Astrophysics, 507 (2): 1141–1201, Bibcode:2009A&A...507.1141L, doi:10.1051/0004-6361/200912304.
2. ^ Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
3. ^ 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.
4. ^ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/s1063772917010085, S2CID 125853869.
5. ^ Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
6. ^ Hiltner, W. A.; et al. (July 1969), "MK Spectral Types for Bright Southern OB Stars", Astrophysical Journal, 157: 313–326, Bibcode:1969ApJ...157..313H, doi:10.1086/150069.
7. ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
8. ^ Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
9. ^ Zorec, J.; et al. (July 2007), "Be star disc characteristics near the central object", Astronomy and Astrophysics, 470 (1): 239–247, Bibcode:2007A&A...470..239Z, doi:10.1051/0004-6361:20066615, hdl:11336/38181.
10. ^ Zorec, J.; et al. (November 2016), "Critical study of the distribution of rotational velocities of Be stars. I. Deconvolution methods, effects due to gravity darkening, macroturbulence, and binarity", Astronomy & Astrophysics, 595: 26, Bibcode:2016A&A...595A.132Z, doi:10.1051/0004-6361/201628760, hdl:11336/37946.
11. ^ Balona, L. A.; et al. (February 1992), "Intensive photometry of southern Be variables. II - Summer objects", Astronomy and Astrophysics Supplement Series, 92 (3): 533–563, Bibcode:1992A&AS...92..533B.
12. ^ Chauville, J.; Zorec, J.; Ballereau, D.; Morrell, N.; Cidale, L.; Garcia, A. (November 2001), "High and intermediate-resolution spectroscopy of Be stars 4481 lines", Astronomy and Astrophysics, 378: 861–882, Bibcode:2001A&A...378..861C, doi:10.1051/0004-6361:20011202, hdl:11336/36962.
13. ^ "10 CMa", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved April 27, 2019.
14. ^ 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.
15. van Belle, Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2, S2CID 119273474.
16. Feinstein, A. (1968). "A Survey of Southern Be Stars. II. Photometric data". Zeitschrift für Astrophysik. 68: 29–47. Bibcode:1968ZA.....68...29F. Retrieved 1 January 2025.
17. Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (October 1973). "59th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 834: 1–22. Bibcode:1973IBVS..834....1K. Retrieved 1 January 2025.
18. Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.

v t e Constellation of Canis Major
Canis Major in Chinese astronomy List of stars in Canis Major
Stars	Bayer α (Sirius) β (Mirzam) γ (Muliphein) δ (Wezen) ε (Adhara) ζ (Furud) η (Aludra) θ ι κ λ μ ν ν ν ξ ξ ο ο π σ (Unurgunite) τ ω Flamsteed 10 11 12 15 17 26 27 29 Variable R W Z UW VY CX EZ FN FS FY LS NR V352 HR 2225 2318 2437 2447 2450 2758 2764 2766 2812 HD 43162 43197 (Amadioha) 45184 45364 47186 54879 Other RX J0720.4−3125 WASP-64 (Atakoraka) WISE 0713−2917 WR 7
Exoplanets ν Canis Majoris b HD 47536 b c HD 47186 b c HD 45364 b c HD 43197 b
Star clusters	NGC NGC 2204 NGC 2354 NGC 2360 NGC 2362 NGC 2374 Other Gaia 1 Messier 41
Nebulae NGC 2359 NGC 2361 Sh2-297
Galaxies	NGC 2207 2217 2227 2280 2283 2293 Other Canis Major Overdensity IC 2163
Astronomical events SN 1999ec SN 2003H
Category

• B-type main-sequence stars
• B-type giants
• Be stars
• Canis Major
• Durchmusterung objects
• Flamsteed objects
• Henry Draper Catalogue objects
• Hipparcos objects
• Bright Star Catalogue objects
• Objects with variable star designations