"The Double Double" redirects here. For other uses, see double-double (disambiguation).
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]
Distance
162 ± 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]
Distance
156 ± 4 ly (48 ± 1 pc)
Absolute magnitude (MV)
1.2[5]
Details
ε1 Lyr A
Mass
2.03[7]M☉
Luminosity
24[7]L☉
Temperature
7,943[7] K
Rotational velocity (v sin i)
165[7] km/s
ε1 Lyr B
Mass
1.61[7]M☉
Luminosity
8.4[7]L☉
Temperature
7,047[7] K
Rotational velocity (v sin i)
159[7] km/s
ε2 Lyr A
Mass
2.11[7]M☉
Luminosity
29[7]L☉
Temperature
7,816[7] K
Rotational velocity (v sin i)
212[7] km/s
ε2 Lyr B
Mass
2.15[7]M☉
Luminosity
32[7]L☉
Temperature
7,852[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.
^ abcdefghijvan 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.
^ abcdefMermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
^ abAbt, 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.
^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.
^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.
^ abcdefghijklmnopZorec, 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.
^Dawes, W R (1867). Catalogue of Micrometrical Measurements of Double Stars. Royal Astronomical Society. p. 409.
EpsilonLyrae (ε Lyr, ε Lyrae), also known as the Double Double, is a multiple star system of at least five stars approximately 162 light-years away in...
that they become egg-shaped and material flows from one to the other. EpsilonLyrae, known informally as the Double Double, is a complex multiple star system...
quadruple star system in the constellation Orion, similar to Mizar and EpsilonLyrae with combined visual magnitude of 4.13. The four stars are known as...
constellation are stars of great distance and high luminosity. At magnitude 1.5, Epsilon Canis Majoris (Adhara) is the second-brightest star of the constellation...
Horizontal-branch stars hotter than the RR Lyrae gap are generally considered to be blue giants, and sometimes the RR Lyrae stars themselves are called blue giants...
spectrograms - XIX. The superficially normal B stars zeta Draconis, epsilonLyrae, 8 Cygni and 22 Cygni", Monthly Notices of the Royal Astronomical Society...
spectrograms - XIX. The superficially normal B stars zeta Draconis, epsilonLyrae, 8 Cygni and 22 Cygni". Monthly Notices of the Royal Astronomical Society...
Eye (of the bull) عين عَيْن Epsilon Tauri Aladfar al-ʼUẓfūr the Talons (of the Swooping Eagle) الأظفر أُظْفُور Eta Lyrae Alawaid al-ʽAwāʼidh the Protecting...
Soung-Chul (2021). "Optical and Near-infrared Pulsation Properties of RR Lyrae and Population II Cepheid Variables in the Messier 15 Globular Cluster"...
causes the system to vary by 0.03 magnitudes. Serpens Caput contains many RR Lyrae variables, although most are too faint to be seen without professional photography...
slightly ellipsoidal shape. This distinguishes them from the so-called beta Lyrae variables and W Ursae Majoris variables, where the two components are so...
(2008). "First Resolved Images Of The Eclipsing And Interacting Binary Beta Lyrae". The Astrophysical Journal. 684 (2): L95–L98. arXiv:0808.0932. Bibcode:2008ApJ...
contact with each other (overcontact binary) and are classed as a Beta Lyrae variable as their light varies from Earth as they eclipse each other. The...
luminosities of giants there are several classes of pulsating variable stars: RR Lyrae variables, pulsating horizontal-branch class A (sometimes F) stars with...
Binary star system 3.23 Epsilon Ophiuchi Star 3.25 3.23 Sigma Puppis Binary star system 3.25 Eta Serpentis Star 3.250 Gamma Lyrae Star 3.26 3.22 Gamma Hydri...
traditional star names, there were some coined in modern times, e.g. "Avior" for Epsilon Carinae (1930), and a number of stars named after people (mostly in the...
designations mark them as variable stars. Examples include R Cygni, RR Lyrae, and GN Andromedae. (Many variable stars also have designations in other...
Nelan, Edmund P. (2011-12-01). "Distance Scale Zero-Points from Galactic RR Lyrae Star Parallaxes". The Astronomical Journal. 142 (6): 187. arXiv:1109.5631...
(two) eyes of the lion'. Mu1 Scorpii is an eclipsing binary of the Beta Lyrae type. Discovered to be a spectroscopic binary by Solon Irving Bailey in...
most of which are RR Lyrae variables. The planetary nebula IC 4699 is of 13th magnitude and lies midway between Alpha and Epsilon Telescopii. IC 4889 is...
less than an hour (for AM CVn stars), or a few days (components of Beta Lyrae), but also hundreds of thousands of years (Proxima Centauri around Alpha...
the Traveler's Moon. Cue Ball is an uninhabitable ice world orbiting Beta Lyrae. Jm'ho is a moon similar to Europa, homeworld to the Gw'oth. It orbits a...
including Antares A (Alpha Scorpii A). Examples of eclipsing binaries are Epsilon Aurigae (Almaaz), VV Cephei, and V766 Centauri (HR 5171). Angular diameter...
light-years from Earth, Delta Pictoris is an eclipsing binary of the Beta Lyrae type. Composed of two blue stars of spectral types B3III and O9V, the system...
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