Epsilon Equulei

Epsilon Equulei
Observation data
Epoch J2000      Equinox J2000
Constellation Equuleus
Right ascension 20h 59m 04.47539s[1]
Declination 04° 17′ 36.5211″[1]
Apparent magnitude (V) 5.23[2] (5.96 / 6.31)[3]
Characteristics
Spectral type F5(V) + F6(V)[4]
U−B color index +0.00[5]
B−V color index +0.47[5]
Astrometry
Radial velocity (Rv)8.20 ± 0.2[6] km/s
Proper motion (μ) RA: -115.75[1] mas/yr
Dec.: -151.70[1] mas/yr
Parallax (π)18.49 ± 1.35 mas[1]
Distance180 ± 10 ly
(54 ± 4 pc)
Absolute magnitude (MV)+1.65[7]
Orbit[3]
Period (P)101.485 yr
Semi-major axis (a)0.6474″
Eccentricity (e)0.705
Inclination (i)92.17°
Longitude of the node (Ω)105.15°
Periastron epoch (T)1920.37
Argument of periastron (ω)
(secondary)		340.19°
Details
A
Mass1.74[8] M☉
Surface gravity (log g)3.87[9] cgs
Temperature6,223[9] K
B
Mass1.53[8] M☉
Surface gravity (log g)4.29[9] cgs
Temperature6,399[9] K
Age1.5[10] Gyr
Other designations
ε Equ, 1 Equulei, HD 199766, HIP 103569, HR 8034, SAO 126428, BD+03° 4473
Database references
SIMBADdata

Epsilon Equulei, Latinized from ε Equulei, is a star system of apparent magnitude +5.23[2] in the constellation of Equuleus. It is located 180 light years away from the Solar System, based on its parallax.[1]

  1. ^ a b c d e f van Leeuwen, F.; et al. (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 "* eps Equ". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 July 2017.
  3. ^ a b "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 1 August 2017. Retrieved 8 July 2017.
  4. ^ Beavers, W. I.; Cook, D. B. (1980). "Scanner studies of composite spectra. I - Dwarfs". The Astrophysical Journal Supplement Series. 44: 489. Bibcode:1980ApJS...44..489B. doi:10.1086/190702.
  5. ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data: 0. Bibcode:1986EgUBV........0M.
  6. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  7. ^ 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.
  8. ^ a b "Multiple Star Catalog". Archived from the original on 2018-11-29. Retrieved 2018-11-28.
  9. ^ a b c d Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". The Astronomical Journal. 150 (3): 88. arXiv:1507.01466. Bibcode:2015AJ....150...88L. doi:10.1088/0004-6256/150/3/88. S2CID 118505114.
  10. ^ Casagrande, L.; Schönrich, R.; Asplund, M.; Cassisi, S.; Ramírez, I.; Meléndez, J.; Bensby, T.; Feltzing, S. (2011). "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey". Astronomy and Astrophysics. 530: A138. arXiv:1103.4651. Bibcode:2011A&A...530A.138C. doi:10.1051/0004-6361/201016276. S2CID 56118016.