Astronomy:Mu Pictoris

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Short description: Variable star in the constellation Pictor
Mu Pictoris
Observation data
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]
Characteristics
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]
Astrometry
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
Distance760 ± 70 ly
(230 ± 20 pc)
Absolute magnitude (MV)0.20/3.75[7]
Details
μ Pic A
Mass3.60±0.09[8] M
Luminosity355[8] L
Temperature10,568[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
SIMBADdata

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.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 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, Bibcode1975MNSSA..34....7H. 
  3. 3.0 3.1 3.2 3.3 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  4. 4.0 4.1 4.2 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, doi:10.1111/j.1365-2966.2010.16609.x, Bibcode2010MNRAS.405.2439O. 
  5. 5.0 5.1 5.2 Corbally, C. J. (1984), "Close visual binaries. I - MK classifications", Astrophysical Journal Supplement Series 55: 657, doi:10.1086/190973, Bibcode1984ApJS...55..657C. 
  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, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  7. Corbally, C. J. (December 1984), "Close visual binaries. III - Parameters and evolutionary status", Astronomical Journal 89: 1887–1896, doi:10.1086/113700, Bibcode1984AJ.....89.1887C. 
  8. 8.0 8.1 8.2 8.3 Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics 537: A120, doi:10.1051/0004-6361/201117691, Bibcode2012A&A...537A.120Z. 
  9. "mu. Pic". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=mu.+Pic. 
  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, doi:10.1093/mnras/277.4.1547, Bibcode1995MNRAS.277.1547B.