Epsilon Lyrae

"The Double Double" redirects here. For other uses, see double-double (disambiguation).
Epsilon Lyrae
Epsilon Lyrae is located in 100x100
Epsilon Lyrae

ε (circled) in the constellation Lyra.
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Lyra
Epsilon1 Lyrae
Right ascension 18h 44m 20.34589s[1]
Declination +39° 40′ 12.4533″[1]
Apparent magnitude (V) 4.66[2]
Epsilon2 Lyrae
Right ascension 18h 44m 22.78056s[1]
Declination +39° 36′ 45.7851″[1]
Apparent magnitude (V) 4.59[2]
Characteristics
ε1 Lyr
Spectral type A3V + F0V[3]
U−B color index +0.065[2]
B−V color index +0.16[2]
ε2 Lyr
Spectral type A6Vn + A7Vn[3]
U−B color index +0.075[2]
B−V color index +0.18[2]
Astrometry
ε1 Lyr
Radial velocity (Rv)−31.20 ± 1.7[4] km/s
Proper motion (μ) RA: 11.09[1] mas/yr
Dec.: 61.39[1] mas/yr
Parallax (π)20.10 ± 0.76 mas[1]
Distance162 ± 6 ly
(50 ± 2 pc)
Absolute magnitude (MV)1.2[5]
ε2 Lyr
Radial velocity (Rv)−24.40 ± 1.7[6] km/s
Proper motion (μ) RA: 6.18[1] mas/yr
Dec.: 50.42[1] mas/yr
Parallax (π)20.97 ± 0.50 mas[1]
Distance156 ± 4 ly
(48 ± 1 pc)
Absolute magnitude (MV)1.2[5]
Details
ε1 Lyr A
Mass2.03[7] M☉
Luminosity24[7] L☉
Temperature7,943[7] K
Rotational velocity (v sin i)165[7] km/s
ε1 Lyr B
Mass1.61[7] M☉
Luminosity8.4[7] L☉
Temperature7,047[7] K
Rotational velocity (v sin i)159[7] km/s
ε2 Lyr A
Mass2.11[7] M☉
Luminosity29[7] L☉
Temperature7,816[7] K
Rotational velocity (v sin i)212[7] km/s
ε2 Lyr B
Mass2.15[7] M☉
Luminosity32[7] L☉
Temperature7,852[7] K
Rotational velocity (v sin i)233[7] km/s
Other designations
ADS 11635, WDS 18443+3940
ε1 Lyr: 4 Lyrae, HIP 91919, BD+39°3509
ε1 Lyr A: HD 173582, HR 7051, SAO 67310
ε1 Lyr B: HD 173583, HR 7052, SAO 67309
Other designations
ε2 Lyr: 5 Lyrae, HIP 91926, BD+39°3510
ε2 Lyr A: HD 173607, HR 7053, SAO 67315
ε2 Lyr B: HD 173608, HR 7054
Database references
ε1 Lyr
ε1 Lyr A
ε1 Lyr B
ε2 Lyr
ε2 Lyr A
ε2 Lyr B

Epsilon Lyrae (ε Lyr, ε Lyrae), also known as the Double Double,[8] is a multiple star system of at least five stars approximately 162 light-years away in the constellation of Lyra.

  1. ^ a b c d e f g h i j 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 c d e f Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
  3. ^ a b Abt, Helmut A.; Morrell, Nidia I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". Astrophysical Journal Supplement. 95: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182.
  4. ^ 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.
  5. ^ a b 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.
  6. ^ Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. S2CID 119323941.
  7. ^ a b c d e f g h i j k l m n o p Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. S2CID 55586789.
  8. ^ Dawes, W R (1867). Catalogue of Micrometrical Measurements of Double Stars. Royal Astronomical Society. p. 409.