Mu Serpentis, Latinized from μ Serpentis, is a binary star[6] in the Serpens Caput (head) section of the equatorial constellation Serpens. It is visible to the naked eye with an apparent visual magnitude of 3.543.[2] Based upon an annual parallax shift of 19.23 mas as seen from Earth,[1] it is located around 170 light years from the Sun.

Mu Serpentis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Serpens
Right ascension 15h 49m 37.20696s[1]
Declination −03° 25′ 48.7358″[1]
Apparent magnitude (V) 3.543[2]
Characteristics
Spectral type A0 V[3]
U−B color index −0.025[2]
B−V color index −0.032[2]
Astrometry
Radial velocity (Rv)−9.4±2.7[4] km/s
Proper motion (μ) RA: −100.28[1] mas/yr
Dec.: +25.99[1] mas/yr
Parallax (π)19.23 ± 0.38 mas[1]
Distance170 ± 3 ly
(52 ± 1 pc)
Absolute magnitude (MV)−0.04[5]
Orbit[6]
Period (P)36±2 yr
Semi-major axis (a)0.110±0.010
Eccentricity (e)0.4±0.3
Inclination (i)103±28°
Longitude of the node (Ω)296±28°
Periastron epoch (T)1988.9±1.8
Argument of periastron (ω)
(secondary)
308±32°
Details
μ Ser A
Mass2.4 ± 0.4[6] M
Luminosity92[7] L
Temperature9,487[7] K
Rotational velocity (v sin i)96[8] km/s
μ Ser B
Mass2.3 ± 0.4 M
Other designations
μ Ser, 32 Serpentis, BD−02° 4052, FK5 585, HD 141513, HIP 77516, HR 5881, SAO 140787[9]
Database references
SIMBADdata

This is an astrometric binary for which coarse orbital elements have been determined based on interferometric observations. The pair orbit each other with a period of around 36 years and an eccentricity of roughly 0.4.[6] The primary member, component A, is a white-hued A-type main sequence star with a stellar classification of A0 V.[3] The nature of the secondary, component B, is less certain – it may be a class A or F type star of unknown luminosity class.[6]

In Chinese astronomy, Mu Serpentis is called 天乳, Pinyin: Tiānrǔ, meaning Celestial Milk, because this star is marking itself and stand alone in Celestial Milk asterism, Root mansion (see : Chinese constellation).[10]

References edit

  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode:1966PDAUC...1....1G.
  3. ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
  4. ^ 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, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
  5. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  6. ^ a b c d e Gontcharov, G. A.; Kiyaeva, O. V. (March 2010), "Photocentric orbits from a direct combination of ground-based astrometry with Hipparcos II. Preliminary orbits for six astrometric binaries", New Astronomy, 15 (3): 324–331, arXiv:1606.08182, Bibcode:2010NewA...15..324G, doi:10.1016/j.newast.2009.09.006, S2CID 119252073.
  7. ^ a b McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  8. ^ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298.
  9. ^ "mu. Ser". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-31.{{cite web}}: CS1 maint: postscript (link)
  10. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 29 日