Alpha Vulpeculae

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Alpha Vulpeculae
Vulpecula IAU.svg
Cercle rouge 100%.svg

Location of α Vulpeculae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Vulpecula
Right ascension 19h 28m 42.330s[1]
Declination +24° 39′ 53.65″[1]
Apparent magnitude (V) 4.40[2]
Characteristics
Spectral type M1 III[3]
B−V color index 1.487[4]
Variable type +1.81[2]
Astrometry
Radial velocity (Rv) −84.91 ± 0.26[4] km/s
Proper motion (μ) RA: –126.13 ± 0.19[1] mas/yr
Dec.: –107.44 ± 0.22[1] mas/yr
Parallax (π) 10.97 ± 0.28[1] mas
Distance 297 ± 8 ly
(91 ± 2 pc)
Details
Radius 42[4] R
Luminosity 400[4] L
Surface gravity (log g) 1.5[4] cgs
Temperature 3,990[4] K
Rotational velocity (v sin i) 4.6[4] km/s
Other designations
Anser, α Vulpeculae, α Vul, Alpha Vul, 6 Vulpeculae, BD+24 3759, CCDM J19288+2442A, FK5 1508, HD 183439, HIP 95771, HR 7405, IDS 19245+2427 A, SAO 87261, WDS J19287+2440A.[5]

Alpha Vulpeculae (Alpha Vul, α Vulpeculae, α Vul) is the brightest star in the constellation Vulpecula. It has a traditional name, variously represented as Lukida, Lucida Anseris, or Anser, a tradition kept from when the constellation had the name Vulpecula et Anser 'the fox and the goose'.

Alpha Vulpeculae is a red giant of spectral class M1 and has apparent magnitude +4.4. It is approximately 297 light years from Earth. It forms a wide optical binary with 8 Vulpeculae.

It has been analysed as a member of the Arcturus stream, a group of stars with high proper motion and metal-poor properties thought to be the remnants of a small galaxy consumed by the Milky Way.[6]

Amateur image of LDN 778 (center) and Alpha Vulpeculae, (red giant, top center).

References[edit]

  1. ^ a b c d e 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. Vizier catalog entry
  2. ^ a b Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data. SIMBAD, Bibcode:1986EgUBV........0M. 
  3. ^ Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics 11: 29, Bibcode:1973ARA&A..11...29M, doi:10.1146/annurev.aa.11.090173.000333. 
  4. ^ a b c d e f g Massarotti, Alessandro; et al. (January 2008), "Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity", The Astronomical Journal 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209. 
  5. ^ "HD 20781 -- High proper-motion Star". SIMBAD Astronomical Database. Centre de données astronomiques de Strasbourg. Retrieved 2014-09-13. 
  6. ^ Eggen, Olin (1971). "The Arcturus Group". Publications of the Astronomical Society of the Pacific 83 (493): 271–85. Bibcode:1971PASP...83..271E. doi:10.1086/129120. [dead link]