HD 134687

This article is about e Lupi. Not to be confused with ε Lupi.
HD 134687
Observation data
Epoch J2000      Equinox J2000
Constellation Lupus
Right ascension 15h 12m 49.58802s[1]
Declination −44° 30′ 01.4867″[1]
Apparent magnitude (V) 4.81[2]
Characteristics
Spectral type B3 IV/V[3]
B−V color index −0.177±0.011[4]
Astrometry
Radial velocity (Rv)+13.5±7.4[5] km/s
Proper motion (μ) RA: −22.015[1] mas/yr
Dec.: −22.164[1] mas/yr
Parallax (π)7.6373 ± 0.9664 mas[1]
Distanceapprox. 430 ly
(approx. 130 pc)
Absolute magnitude (MV)−1.11[4]
Orbit[6]
Period (P)0.901407 d
Eccentricity (e)≤ 0.03
Periastron epoch (T)0.366
Details
e Lup A
Mass6.0±0.1[7] M☉
Radius7.1[8] R☉
Luminosity (bolometric)997[2] L☉
Temperature17,100[2] K
Rotational velocity (v sin i)13[9] km/s
Age20.3±4.8 Myr
Other designations
e Lup, CD−44° 9932, HD 134687, HIP 74449, HR 5651, SAO 225539[10]
Database references
SIMBADdata

HD 134687 (e Lupi) is a binary star system in the southern constellation Lupus. It is visible to the naked eye with an apparent visual magnitude of 4.81.[2] The distance to HD 134687 can be estimated from its annual parallax shift of 7.6 mas,[1] yielding roughly 430 light years. It is a member of the ~11 million year old Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association, the closest OB association to the Sun.[11]

This is a single-lined spectroscopic binary star system. The pair have a nearly circular orbit with an eccentricity of at or below 0.03 and a period of 0.901407 days (21.6338 h). The primary has an a sin i value of 2.735×105 km, which only gives a lower bound for the semimajor axis a since the orbital inclination i to the line of sight is unknown.[6] The system is a source for X-ray emission.[12]

The visible component has a stellar classification of B3 IV/V,[3] matching a B-type star showing a spectrum with mixed traits of a main sequence and a subgiant star. It is 20 million years old with a projected rotational velocity of 13 km/s.[9] The star has 6.0[7] times the mass of the Sun and 7.1[8] times the Sun's radius. It is radiating 997[2] times the Sun's luminosity from its photosphere at an effective temperature of 17,100 K.[2]

  1. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Buscombe1962 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference cadars was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Wolff2007 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Chen2012 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Berghoefer1996 was invoked but never defined (see the help page).