Epsilon² Arae

Epsilon² Arae
	The location of ε2 Arae (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Ara
Right ascension	17h 03m 08.70964s
Declination	–53° 14′ 13.3020″
Apparent magnitude (V)	5.29 (5.44/8.65)
Characteristics
Spectral type	F5 V Fe+0.5
U−B color index	+0.015
B−V color index	+0.48
Astrometry
Radial velocity (Rv)	+4.9 km/s
Proper motion (μ)	RA: +0.15 mas/yr ; Dec.: −165.20 mas/yr
Parallax (π)	36.73 ± 0.63 mas
Distance	89 ± 2 ly ; (27.2 ± 0.5 pc)
Absolute magnitude (MV)	3.27
Details
Surface gravity (log g)	4.29 cgs
Temperature	6,577 K
Metallicity [Fe/H]	+0.02 dex
Rotational velocity (v sin i)	45.4 km/s
Age	1.9 Gyr
Other designations
	CPD−53° 8316, GJ 3985, HD 153580, HIP 83431, HR 6314, SAO 244388.
Database references
SIMBAD	data

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

^ ^a ^b ^c ^d ^e 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.
^ ^a ^b ^c 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.
^ ^a ^b 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, S2CID 14878976.
^ ^a ^b 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, S2CID 119476992.
^ ^a ^b "* eps02 Ara". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2015-03-03.
^ ^a ^b 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, S2CID 118577511.
^ ^a ^b ^c ^d 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.
^ Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377^{[permanent dead link‍]}
^ "GJ 2125 -- White Dwarf", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2010-07-28.

External links

[aaa474_2_653-1] 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.

[mnrassa27_11-2] 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.

[mnras389_2_869-3] 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, S2CID 14878976.

[aj132_1_161-4] 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, S2CID 119476992.

[SIMBAD-5] "* eps02 Ara". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2015-03-03.

[aaass501_3_941-6] 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, S2CID 118577511.

[apj354-7] 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.

[aaa493_3_1099-8] Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377^{[permanent dead link‍]}

[SIMBAD2-9] "GJ 2125 -- White Dwarf", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2010-07-28.

[1]

Observation data Epoch J2000 Equinox J2000
The location of ε² Arae (circled)
Constellation	Ara
Right ascension	17^h 03^m 08.70964^s^[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 (R_v)	+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 mas^[1]
Distance	89 ± 2 ly (27.2 ± 0.5 pc)
Absolute magnitude (M_V)	3.27^[7]

Details

Surface gravity (log g)	4.29^[7] cgs
Temperature	6,577^[7] K
Metallicity [Fe/H]	+0.02^[7] dex
Rotational velocity (v sin i)	45.4^[8] km/s
Age	1.9^[6] Gyr

Other designations
CPD−53° 8316, GJ 3985, HD 153580, HIP 83431, HR 6314, SAO 244388.^[5]
Database references
SIMBAD	data