HY Velorum

HY Velorum

A visual band light curve for HY Velorum, adapted from Waelkens and Rufener (1985)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Vela
Right ascension 08h 42m 25.38667s[2]
Declination −53° 06′ 50.3324″[2]
Apparent magnitude (V) 4.81 - 4.86[3]
Characteristics
Spectral type B3 IV[4]
B−V color index −0.173±0.007[5]
Variable type SPB[3]
Astrometry
Radial velocity (Rv)+15.6±0.2[5] km/s
Proper motion (μ) RA: −24.83[6] mas/yr
Dec.: +23.21[6] mas/yr
Parallax (π)7.1141 ± 0.2302 mas[2]
Distance460 ± 10 ly
(141 ± 5 pc)
Absolute magnitude (MV)−1.25[5]
Orbit[7]
Period (P)8.378±0.001 d
Eccentricity (e)0.24±0.04
Periastron epoch (T)2450741.3 ± 0.2 HJD
Argument of periastron (ω)
(secondary)		93±9°
Semi-amplitude (K1)
(primary)		8.0±0.3 km/s
Details
HY Vel Aa
Mass5.4[8] M☉
Luminosity830+927
−743[8] L☉
Surface gravity (log g)4.07[9] cgs
Temperature16,865+235
−231[8] K
Metallicity [Fe/H]0.03±0.02[9] dex
Rotational velocity (v sin i)45[8] km/s
Age179[10] Myr
Other designations
HY Vel, CPD−52° 1607, HD 74560, HIP 42726, HR 3467, SAO 236205, WDS J08424-5307A[11]
Database references
SIMBADdata

HY Velorum is a binary star[7] system in the southern constellation of Vela. It is a dim star but visible to the naked eye with an apparent visual magnitude of 4.83.[5] The distance to this system, as estimated from its annual parallax shift of 7.1 mas,[2] is 460 light years. HY Vel most likely forms a gravitationally bound pair with the magnitude 5.45 binary system KT Vel (HD 74535);[12] both are members of the IC 2391 open cluster.[13] As of 1998, HY Vel and KT Vel had an angular separation of 76.1″ along a position angle of 311°.[14]

This is a single-lined spectroscopic binary system with an orbital period of 8.4 days and an eccentricity of 0.24. The visible component has an a sin i value of 0.006 AU, where a is the semimajor axis and i is the (unknown) orbital inclination to the line of sight.

The primary is a slowly pulsating B-type star having at least three pulsational modes, with the dominant mode showing a frequency of 0.64472 cycles per day,[7] corresponding to the catalogued period of 1.55106 days.[3] It has a stellar classification of B3 IV, matching a B-type subgiant star.[4]

  1. ^ Cite error: The named reference Waelkens was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference gcvs was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference DeCat2000 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Szewczuk2015 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Niemczura2003 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Dodd2007 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).