Mu Pictoris

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Mu Pictoris
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Pictor
Right ascension 06h 31m 58.31021s[1]
Declination −58° 45′ 13.8117″[1]
Apparent magnitude (V) 5.69[2] (5.71 + 9.43)[3]
Spectral type B9 Ve[4] or B9 IVn + A8 V:p?[5]
U−B color index −0.17[2]
B−V color index −0.06[2]
Radial velocity (Rv) +0.40±1.00[6] km/s
Proper motion (μ) RA: −1.34[1] mas/yr
Dec.: +1.77[1] mas/yr
Parallax (π) 4.31 ± 0.38[1] mas
Distance 760 ± 70 ly
(230 ± 20 pc)
Absolute magnitude (MV) 0.20/3.75[7]
μ Pic A
Mass 3.60±0.09[8] M
Luminosity 355[8] L
Temperature 10,568[8] K
Rotational velocity (v sin i) 228[8] km/s
Other designations
μ Pic, CPD−58° 722, HD 46860, HIP 31137, HR 2412, SAO 234564[9]
Database references

μ Pictoris, Latinised as Mu Pictoris, is a binary star[3] system in the southern constellation Pictor. It is bright enough to be dimly visible to the naked eye, having a combined apparent visual magnitude of 5.69.[2] Based upon an annual parallax shift of 4.31 mas as seen from Earth,[1] the system is located roughly 760 light years distant from the Sun. As of 2010, the pair have an angular separation of 2.46 arc seconds along a position angle of 221°.[4]

The primary, designated component A, is a blue-white star with a visual magnitude of 5.71[3] and a stellar classification of B9 Ve[4] or B9 IVn.[5] The first classification suggests is a B-type main-sequence star, with the 'e' suffix indicating a Be star. The second may instead indicate a somewhat more evolved B-type star that is spinning rapidly, resulting in "nebulous" absorption lines. Photometrically, it shows a pulsation period of 0.397 days, which is likely the same as the rotation period.[10]

The secondary companion, component B, is a white-hued star of magnitude 9.43[3] with a classification of A8 V:p?.[5] This indicates it is an A-type main-sequence star, with the 'p?' suffix suggesting it may be chemically peculiar while the ':' notation says there is some uncertainty about the general classification.


  1. ^ a b c d e f 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. ^ a b c d Hurly, P. R. (1975), "Combined-light UBV Photometry of 103 Bright Southern Visual Doubles", Monthly Notes of the Astronomical Society of Southern Africa, 34: 7, Bibcode:1975MNSSA..34....7H. 
  3. ^ a b c d 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, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x. 
  4. ^ a b c Oudmaijer, René D.; Parr, Andrew M. (July 2010), "The binary fraction and mass ratio of Be and B stars: a comparative Very Large Telescope/NACO study", Monthly Notices of the Royal Astronomical Society, 405 (4): 2439−2446, Bibcode:2010MNRAS.405.2439O, doi:10.1111/j.1365-2966.2010.16609.x. 
  5. ^ a b c Corbally, C. J. (1984), "Close visual binaries. I - MK classifications", Astrophysical Journal Supplement Series (ISSN 0067-0049), 55: 657, Bibcode:1984ApJS...55..657C, doi:10.1086/190973. 
  6. ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, Bibcode:2012A&A...546A..61D, arXiv:1208.3048Freely accessible, doi:10.1051/0004-6361/201219219, A61. 
  7. ^ Corbally, C. J. (December 1984), "Close visual binaries. III - Parameters and evolutionary status", Astronomical Journal, 89: 1887−1896, Bibcode:1984AJ.....89.1887C, doi:10.1086/113700. 
  8. ^ a b c d Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, Bibcode:2012A&A...537A.120Z, arXiv:1201.2052Freely accessible, doi:10.1051/0004-6361/201117691. 
  9. ^ "mu. Pic". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-08. 
  10. ^ Balona, L. A. (December 1995), "Tests of the Pulsation and Starspot Models for the Periodic Be-Stars", Monthly Notices of the Royal Astronomical Society, 277 (4): 1547, Bibcode:1995MNRAS.277.1547B, doi:10.1093/mnras/277.4.1547.