Theta Reticuli

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Theta Reticuli
Diagram showing star positions and boundaries of the Reticulum constellation and its surroundings
Cercle rouge 100%.svg

Location of θ Reticuli (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Reticulum
Right ascension 04h 17m 40.26515s[1]
Declination −63° 15′ 11.0072″[1]
Apparent magnitude (V) 5.8569±19.7704[1]
Spectral type B9III-IV[2]
B−V color index −0.061±0.009[1]
Proper motion (μ) RA: +5.26[1] mas/yr
Dec.: +35.26[1] mas/yr
Parallax (π) 7.08 ± 0.33[1] mas
Distance 460 ± 20 ly
(141 ± 7 pc)
Absolute magnitude (MV) −0.04[3]
θ Ret A
Mass 3.363±0.117[3] M
Luminosity 179[3] L
Temperature 11,967[3] K
Age 166[3] Myr
θ Ret B
Mass ≥ 1.18[3] M
Other designations
θ Ret, CPD−63 316A, HD 27657, HIP 20020, HR 1372, SAO 248986.[4]
Database references

Theta Reticuli (Theta Ret, θ Reticuli, θ Ret) is double star in constellation of Reticulum, with an apparent magnitude of +5.24. The primary component is a blue B-type giant. It is approximately 462 light years from Earth. This system is a source of X-ray emission, which may be coming from the companion.[3]

Theta Reticuli is moving through the Galaxy at a speed of 7 km/s relative to the Sun. Its projected Galactic orbit carries it between 23,800 and 30,100 light years from the center of the Galaxy.[5][better source needed]


  1. ^ a b c d e f g van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, 
  3. ^ a b c d e f g Hubrig, S.; et al. (June 2001), "Search for low-mass PMS companions around X-ray selected late B stars", Astronomy and Astrophysics, 372: 152−164, Bibcode:2001A&A...372..152H, arXiv:astro-ph/0103201Freely accessible, doi:10.1051/0004-6361:20010452. 
  4. ^ "tet Ret -- Variable Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-02-16. 
  5. ^ Theta Reticuli (HIP 20020)