Zeta Lupi

ζ Lupi
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lupus
Right ascension 15h 12m 17.09595s[1]
Declination −52° 05′ 57.2919″[1]
Apparent magnitude (V) 3.41[2] (3.50 + 6.74)[3]
Characteristics
Spectral type G7 III[4]
U−B color index +0.66[2]
B−V color index +0.92[2]
Astrometry
Radial velocity (Rv)−10.0±0.6[5] km/s
Proper motion (μ) RA: −112.92[1] mas/yr
Dec.: −71.18[1] mas/yr
Parallax (π)27.80 ± 0.15 mas[1]
Distance117.3 ± 0.6 ly
(36.0 ± 0.2 pc)
Absolute magnitude (MV)0.65[6]
Details[7]
ζ Lup A
Mass2.56±0.10 M☉
Radius9.00±0.18 R☉
Luminosity49.9±1.7 L☉
Surface gravity (log g)2.930±0.094 cgs
Temperature5,114±36 K
Metallicity [Fe/H]0.022±0.024 dex
Other designations
ζ Lup, CD−51°8830, FK5 558, GJ 9512 A, HD 134505, HIP 74395, HR 5649, SAO 242304, WDS J15123-5206A[8]
Database references
SIMBADdata

ζ Lupi (Latinised as Zeta Lupi) is the brighter component of a wide double star in the constellation Lupus, consisting of an orange-hued primary and a fainter secondary with a golden-yellow hue.[9] It is visible to the naked eye with a combined apparent visual magnitude of 3.41.[2] Based upon an annual parallax shift of 27.80[1] mas as seen from Earth, it is located 117.3 light-years from the Sun.

This is a probable binary star system.[10] As of 2013, the pair had an angular separation of 71.20 arcseconds along a position angle of 249°.[3] The primary, component A, is an evolved G-type giant star with a visual magnitude of 3.50[3] and a stellar classification of G7 III.[4] This is a red clump star, indicating that it is generating energy through the thermonuclear fusion of helium in its core region.[11] It is 2.6 times more massive than the Sun and nine times larger. Zeta Lupi is 50 times more luminous than the Sun, emmiting this energy from its photosphere at an effective temperature of 5114 K.[7]

The secondary, component B, has a visual magnitude of 6.74.[3]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gray2006 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. ^ Cite error: The named reference Pizzolato2000 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference ottoni was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Streicher2007 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference laney2012 was invoked but never defined (see the help page).