Xi Andromedae

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Not to be confused with 11 Andromedae.
For Andromeda XI (Andromeda 11), see List of Andromeda's satellite galaxies.
Xi Andromedae
Diagram showing star positions and boundaries of the Andromeda constellation and its surroundings
Cercle rouge 100%.svg

Location of ξ Andromedae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 01h 22m 20.41924s[1]
Declination +45° 31′ 43.6003″[1]
Apparent magnitude (V) +4.90[2]
Spectral type K0 IIIb[3]
U−B color index +0.98[2]
B−V color index +1.08[2]
Radial velocity (Rv) –12.59[4] km/s
Proper motion (μ) RA: +31.45[1] mas/yr
Dec.: +8.83[1] mas/yr
Parallax (π) 15.21 ± 0.28[1] mas
Distance 214 ± 4 ly
(66 ± 1 pc)
Absolute magnitude (MV) 0.550[5]
Mass 2.5[5] M
Radius 10[6] R
Luminosity 45.7[6] L
Surface gravity (log g) 2.8[6] cgs
Temperature 4,656[6] K
Metallicity [Fe/H] +0.03[6] dex
Rotational velocity (v sin i) 0.0[6] km/s
Other designations
Adhil, 46 Andromedae, BD+44 287, FK5 1035, HD 8207, HIP 6411, HR 390, SAO 37155.

Xi Andromedae (ξ And, ξ Andromedae) is a solitary[3] star in the northern constellation of Andromeda. It bears the traditional name Adhil, which is derived from the Arabic الذيل að-ðayl "the train" (lit. "the tail"). It has an apparent magnitude of +4.9[2] and lies at a distance of roughly 214 light-years (66 parsecs) from Earth.[1]

Johann Bayer labeled this star "ξ" in his Uranometria. The star appeared in John Flamsteed's Atlas Coelestis, but was unlabeled. It was later designated as 46 Andromedae by Jérôme Lalande. The label "ξ" was used in Atlas Coelestis, apparently erroneously, for what Bayer had labeled "A" (Bayer's A Andromedae has the Flamsteed designation 49 Andromedae).[citation needed]

This star is a red clump giant star that has begun generating energy through the fusion of helium at its core, having passed through the red giant branch of its evolution.[5] It has a stellar classification of K0 IIIb,[3] with 2.5[5] times the mass of the Sun and 10[6] times the Sun's radius. Xi Andromedae is emitting nearly 46[6] times as much luminosity as the Sun from its outer envelope at an effective temperature of 4,656 K,[6] giving it the orange-hued glow of a K-type star. It has no measurable projected rotational velocity,[6] although this may simply mean that the star's pole of rotation is facing in the general direction of the Earth.


  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. 
  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). Bibcode:1966CoLPL...4...99J. 
  3. ^ a b c 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. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x.  Note that the 1991 Bright Star Catalogue has listed this as a spectroscopic binary with a period of 17.7673d.
  4. ^ Famaey, B. et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272. 
  5. ^ a b c d Mishenina, T. V. et al. (September 2006), "Elemental abundances in the atmosphere of clump giants", Astronomy and Astrophysics 456 (3): 1109–1120, arXiv:astro-ph/0605615, Bibcode:2006A&A...456.1109M, doi:10.1051/0004-6361:20065141 
  6. ^ a b c d e f g h i j 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. 

External links[edit]