Epsilon2 Arae

For other star systems with this Bayer designation, see Epsilon Arae.
Epsilon2 Arae
Diagram showing star positions and boundaries of the Ara constellation and its surroundings


The location of ε2 Arae (circled)

Observation data
Epoch J2000      Equinox J2000
Constellation Ara
Right ascension 17h 03m 08.70964s[1]
Declination –53° 14′ 13.3020″[1]
Apparent magnitude (V) 5.29[2] (5.44/8.65)[3]
Characteristics
Spectral type F5 V Fe+0.5[4]
U−B color index +0.015[5]
B−V color index +0.48[2]
Astrometry
Radial velocity (Rv)+4.9[6] km/s
Proper motion (μ) RA: +0.15[1] mas/yr
Dec.: −165.20[1] mas/yr
Parallax (π)36.73 ± 0.63[1] mas
Distance89 ± 2 ly
(27.2 ± 0.5 pc)
Absolute magnitude (MV)3.27[7]
Details
Surface gravity (log g)4.29[7] cgs
Temperature6,577[7] K
Metallicity [Fe/H]+0.02[7] dex
Rotational velocity (v sin i)45.4[8] km/s
Age1.9[6] Gyr
Other designations
CPD−53° 8316, GJ 3985, HD 153580, HIP 83431, HR 6314, SAO 244388.[5]

Epsilon2 Arae (ε2 Arae, ε2 Ara) is the Bayer designation for a double star in the southern constellation of Ara. It is approximately 89 light-years (27 parsecs) distant from Earth. With an apparent visual magnitude of 5.3,[2] it is faintly visible to the naked eye.

The brighter star is a magnitude 5.44 F-type main sequence star with a stellar classification of F5 V Fe+0.5.[4] The Fe+0.5 notation indicates that it has a somewhat higher than normal abundance of iron. It has a magnitude 8.65 companion at an angular separation of 0.590 arcseconds.[3] It has a common proper motion white dwarf companion, WDS J17031-5314, with a magnitude of 13.47.[9]

References

  1. 1 2 3 4 5 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. 1 2 3 Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa 27: 11, Bibcode:1968MNSSA..27...11C.
  3. 1 2 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.
  4. 1 2 Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I", The Astronomical Journal 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637.
  5. 1 2 "* eps02 Ara". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2015-03-03.
  6. 1 2 Holmberg, J.; Nordström, B.; Andersen, J. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics Supplement Series 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191.
  7. 1 2 3 4 Balachandran, Suchitra (May 1, 1990), "Lithium depletion and rotation in main-sequence stars", Astrophysical Journal, Part 1 354: 310–332, Bibcode:1990ApJ...354..310B, doi:10.1086/168691.
  8. ↑ Schröder, C.; Reiners, A.; Schmitt, J. H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo", Astronomy and Astrophysics 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377.
  9. ↑ "GJ 2125 -- White Dwarf", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), retrieved 2010-07-28.

External links

This article is issued from Wikipedia - version of the Monday, March 07, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.