HD 73634 is a single[8] star in the southern constellation of Vela. It has the Bayer designation e Velorum; HD 73634 is the star's designation from the Henry Draper Catalogue. The star is white in hue and is faintly visible to the naked eye, having an apparent visual magnitude of +4.11.[2] Parallax measurements provide a distance estimate of approximately 1,800 light years from the Sun. It is drifting further away with a radial velocity of +19 km/s.[2]

HD 73634
Observation data
Epoch J2000.0 (ICRS)      Equinox J2000.0 (ICRS)
Constellation Vela
Right ascension 08h 37m 38.63278s[1]
Declination −42° 59′ 20.6894″[1]
Apparent magnitude (V) +4.11[2]
Spectral type A7Ia[3] or A6II[4]
B−V color index 0.109±0.011[2]
Radial velocity (Rv)+19.3±0.6[2] km/s
Proper motion (μ) RA: −10.75±0.13[1] mas/yr
Dec.: +9.66±0.12[1] mas/yr
Parallax (π)1.79 ± 0.15 mas[1]
Distance1,800 ± 200 ly
(560 ± 50 pc)
Absolute magnitude (MV)−4.61[2]
Mass7.8±0.2[5] M
[6] R
Luminosity4,140.2±594.5[6] L
[6] K
Age39.8±4.9[5] Myr
Other designations
e Vel, CD−42°4451, FK5 324, GC 11852, HD 73634, HIP 42312, HR 3426, SAO 220204[7]
Database references

This evolved object has received stellar classifications of A7Ia[3] and A6II,[4] indicating that it is a massive supergiant or bright giant star. It has 7.8 times the mass of the Sun and is around 40 million years old.[5] The star has expanded to nearly 34 times the girth of the Sun and is radiating around 4,140 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 7,977 K.[6]


  1. ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy & Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog entry
  2. ^ a b c d e f 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.
  3. ^ a b Stephenson, C. B.; Sanduleak, N. (1971). "Luminous stars in the Southern Milky Way". Publication of the Warner and Swasey Observatory. Cleveland, Ohio: Case Western Reserve University. 1: 1. Bibcode:1971PW&SO...1a...1S.
  4. ^ a b Gray, R. O.; Garrison, R. F. (1989). "The Late A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation". The Astrophysical Journal Supplement Series. 70: 623. Bibcode:1989ApJS...70..623G. doi:10.1086/191349.
  5. ^ a b c Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (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.
  6. ^ a b c d 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.
  7. ^ "e Vel". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-01-08.
  8. ^ 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.