From Wikipedia, the free encyclopedia
μ Andromedae
Location of μ Andromedae (circled)
Observation data
Epoch J2000       Equinox J2000
Constellation Andromeda
Right ascension 00h 56m 45.21211s [1]
Declination +38° 29′ 57.6380″ [1]
Apparent magnitude (V) 3.87 [2]
Characteristics
Spectral type A5 V [3]
U−B color index +0.15 [2]
B−V color index +0.12 [2]
Astrometry
Radial velocity (Rv)+7.6 [4] km/s
Proper motion (μ) RA: +153.48 [1]  mas/ yr
Dec.: +36.49 [1]  mas/ yr
Parallax (π)25.14 ± 0.86  mas [1]
Distance130 ± 4  ly
(40 ± 1  pc)
Absolute magnitude (MV)+0.86 [5]
Orbit [6]
Period (P)550.7 ± 0.2 d
Semi-major axis (a)46.66 ± 0.06 mas
Eccentricity (e)0.8405 ± 0.0009
Inclination (i)52.5 ± 0.3°
Longitude of the node (Ω)−17.6 ± 0.2°
Periastron epoch (T)55765.45 ± 0.04 MJD
Argument of periastron (ω)
(secondary)
168.9 ± 0.3°
Semi-amplitude (K1)
(primary)
11.1 ± 0.5 km/s
Details
Mass2.0 [7]  M
Radius2.4 [7]  R
Luminosity21 [7]  L
Surface gravity (log g)3.99 [7]  cgs
Temperature7,959 [8]  K
Metallicity [Fe/H]+0.03 [8]  dex
Rotational velocity (v sin i)75 [9] km/s
Age600 [10]  Myr
Other designations
μ Andromedae, μ And, Mu And, 37 Andromedae, BD+37°175, FK5 33, HD 5448, HIP 4436, HR 269, SAO 54281, PPM 65785
Database references
SIMBAD data

Mu Andromedae (Mu And, μ Andromedae, μ And) is the Bayer designation for a star in the northern constellation of Andromeda. It has an apparent visual magnitude of 3.87, [2] making it readily visible to the naked eye. Based upon parallax measurements, it is approximately 130 light-years (40 parsecs) from Earth. [1] In the constellation, the star is situated about halfway between the bright star Mirach to the southwest and the Andromeda Galaxy (M31) to the northeast. [11]

The spectrum of this star matches a stellar classification of A5 V, [3] indicating that it is an A-type main sequence star. It has double the mass of the Sun and 2.4 times the Sun's radius. [7] The star is radiating about 21 [7] times the luminosity of the Sun from its outer envelope at an effective temperature of 7,959 K, [8] giving it the characteristic white glow of an A-type star. [12] It is estimated to be about 600 million years old, [10] with a relatively high projected rotational velocity of 75 km/s. [9] Mu Andromedae has recently been found to be a binary system. The two stars orbit each other every 550.7 days. [6]

Naming

In Chinese, 奎宿 (Kuí Sù), meaning Legs (asterism), refers to an asterism consisting of μ Andromedae, η Andromedae, 65 Piscium, ζ Andromedae, ε Andromedae, δ Andromedae, π Andromedae, ν Andromedae, β Andromedae, σ Piscium, τ Piscium, 91 Piscium, υ Piscium, φ Piscium, χ Piscium and ψ¹ Piscium. Consequently, the Chinese name for μ Andromedae itself is 奎宿八 (Kuí Sù bā, English: the Eighth Star of Legs.) [13]

References

  1. ^ a b c d e f van Leeuwen, F. (November 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 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode: 1966CoLPL...4...99J.
  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. ^ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington D.C., Bibcode: 1953GCRV..C......0W.
  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 Roettenbacher, R.M.; Monnier, J.D.; Korhonen, H.; Aarnio, A.N.; Baron, F.; Che, X.; Harmon, R.O.; Kővári, Zs.; Kraus, S.; Schaefer, G.H.; Torres, G.; Zhao, M.; Ten Brummelaar, T.A.; Sturmann, J.; Sturmann, L. (2016). "No Sun-like dynamo on the active star ζ Andromedae from starspot asymmetry". Nature. 533 (7602): 217–220. arXiv: 1709.10107. Bibcode: 2016Natur.533..217R. doi: 10.1038/nature17444. PMID  27144357. S2CID  4466687.
  7. ^ a b c d e f Malagnini, M. L.; Morossi, C. (November 1990), "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars", Astronomy and Astrophysics Supplement Series, 85 (3): 1015–1019, Bibcode: 1990A&AS...85.1015M.
  8. ^ a b c Gardiner, R. B.; Kupka, F.; Smalley, B. (July 1999), "Testing convection theories using Balmer line profiles of A, F, and G stars", Astronomy and Astrophysics, 347: 876–890, Bibcode: 1999A&A...347..876G.
  9. ^ a b 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.
  10. ^ a b Rieke, G. H.; et al. (February 2005), "Decay of Planetary Debris Disks", The Astrophysical Journal, 620 (2): 1010–1026, Bibcode: 2005ApJ...620.1010R, CiteSeerX  10.1.1.579.8956, doi: 10.1086/426937, S2CID  54676993.
  11. ^ Reddy, Francis (2011), Celestial Delights: The Best Astronomical Events Through 2020 (3rd ed.), Springer, p. 236, ISBN  978-1461406099.
  12. ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on March 18, 2012, retrieved 2012-01-16.
  13. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日
From Wikipedia, the free encyclopedia
μ Andromedae
Location of μ Andromedae (circled)
Observation data
Epoch J2000       Equinox J2000
Constellation Andromeda
Right ascension 00h 56m 45.21211s [1]
Declination +38° 29′ 57.6380″ [1]
Apparent magnitude (V) 3.87 [2]
Characteristics
Spectral type A5 V [3]
U−B color index +0.15 [2]
B−V color index +0.12 [2]
Astrometry
Radial velocity (Rv)+7.6 [4] km/s
Proper motion (μ) RA: +153.48 [1]  mas/ yr
Dec.: +36.49 [1]  mas/ yr
Parallax (π)25.14 ± 0.86  mas [1]
Distance130 ± 4  ly
(40 ± 1  pc)
Absolute magnitude (MV)+0.86 [5]
Orbit [6]
Period (P)550.7 ± 0.2 d
Semi-major axis (a)46.66 ± 0.06 mas
Eccentricity (e)0.8405 ± 0.0009
Inclination (i)52.5 ± 0.3°
Longitude of the node (Ω)−17.6 ± 0.2°
Periastron epoch (T)55765.45 ± 0.04 MJD
Argument of periastron (ω)
(secondary)
168.9 ± 0.3°
Semi-amplitude (K1)
(primary)
11.1 ± 0.5 km/s
Details
Mass2.0 [7]  M
Radius2.4 [7]  R
Luminosity21 [7]  L
Surface gravity (log g)3.99 [7]  cgs
Temperature7,959 [8]  K
Metallicity [Fe/H]+0.03 [8]  dex
Rotational velocity (v sin i)75 [9] km/s
Age600 [10]  Myr
Other designations
μ Andromedae, μ And, Mu And, 37 Andromedae, BD+37°175, FK5 33, HD 5448, HIP 4436, HR 269, SAO 54281, PPM 65785
Database references
SIMBAD data

Mu Andromedae (Mu And, μ Andromedae, μ And) is the Bayer designation for a star in the northern constellation of Andromeda. It has an apparent visual magnitude of 3.87, [2] making it readily visible to the naked eye. Based upon parallax measurements, it is approximately 130 light-years (40 parsecs) from Earth. [1] In the constellation, the star is situated about halfway between the bright star Mirach to the southwest and the Andromeda Galaxy (M31) to the northeast. [11]

The spectrum of this star matches a stellar classification of A5 V, [3] indicating that it is an A-type main sequence star. It has double the mass of the Sun and 2.4 times the Sun's radius. [7] The star is radiating about 21 [7] times the luminosity of the Sun from its outer envelope at an effective temperature of 7,959 K, [8] giving it the characteristic white glow of an A-type star. [12] It is estimated to be about 600 million years old, [10] with a relatively high projected rotational velocity of 75 km/s. [9] Mu Andromedae has recently been found to be a binary system. The two stars orbit each other every 550.7 days. [6]

Naming

In Chinese, 奎宿 (Kuí Sù), meaning Legs (asterism), refers to an asterism consisting of μ Andromedae, η Andromedae, 65 Piscium, ζ Andromedae, ε Andromedae, δ Andromedae, π Andromedae, ν Andromedae, β Andromedae, σ Piscium, τ Piscium, 91 Piscium, υ Piscium, φ Piscium, χ Piscium and ψ¹ Piscium. Consequently, the Chinese name for μ Andromedae itself is 奎宿八 (Kuí Sù bā, English: the Eighth Star of Legs.) [13]

References

  1. ^ a b c d e f van Leeuwen, F. (November 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 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode: 1966CoLPL...4...99J.
  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. ^ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington D.C., Bibcode: 1953GCRV..C......0W.
  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 Roettenbacher, R.M.; Monnier, J.D.; Korhonen, H.; Aarnio, A.N.; Baron, F.; Che, X.; Harmon, R.O.; Kővári, Zs.; Kraus, S.; Schaefer, G.H.; Torres, G.; Zhao, M.; Ten Brummelaar, T.A.; Sturmann, J.; Sturmann, L. (2016). "No Sun-like dynamo on the active star ζ Andromedae from starspot asymmetry". Nature. 533 (7602): 217–220. arXiv: 1709.10107. Bibcode: 2016Natur.533..217R. doi: 10.1038/nature17444. PMID  27144357. S2CID  4466687.
  7. ^ a b c d e f Malagnini, M. L.; Morossi, C. (November 1990), "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars", Astronomy and Astrophysics Supplement Series, 85 (3): 1015–1019, Bibcode: 1990A&AS...85.1015M.
  8. ^ a b c Gardiner, R. B.; Kupka, F.; Smalley, B. (July 1999), "Testing convection theories using Balmer line profiles of A, F, and G stars", Astronomy and Astrophysics, 347: 876–890, Bibcode: 1999A&A...347..876G.
  9. ^ a b 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.
  10. ^ a b Rieke, G. H.; et al. (February 2005), "Decay of Planetary Debris Disks", The Astrophysical Journal, 620 (2): 1010–1026, Bibcode: 2005ApJ...620.1010R, CiteSeerX  10.1.1.579.8956, doi: 10.1086/426937, S2CID  54676993.
  11. ^ Reddy, Francis (2011), Celestial Delights: The Best Astronomical Events Through 2020 (3rd ed.), Springer, p. 236, ISBN  978-1461406099.
  12. ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on March 18, 2012, retrieved 2012-01-16.
  13. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日

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