Binary star system in the constellation of Lyra
Delta1 Lyrae
Observation dataEpoch J2000.0 Equinox J2000.0
Constellation
Lyra
Right ascension 18h 53m 43.55924s [ 1]
Declination
+36° 58′ 18.1891″[ 1]
Apparent magnitude (V)5.56[ 2]
Characteristics
Spectral type
B2.5V[ 3] [ 4]
U−B color index
−0.67[ 2]
B−V color index
−0.15[ 2]
Astrometry Radial velocity (Rv )−25.8[ 5] km/s Proper motion (μ) RA: +1.350[ 1] mas /yr Dec.: −2.985[ 1] mas /yr Parallax (π)2.8072± 0.1334 mas [ 1] Distance 1,160 ± 60 ly pc ) Absolute magnitude (MV )−1.55[ 6] Orbit [ 7] Period (P)88.352 days Semi-major axis (a)≥46.8 Gm (0.313 AU ) Eccentricity (e)± 0.03Periastron epoch (T)428 406 .613± 0.500 JD Argument of periastron (ω)± 0.1Semi-amplitude 1 )± 1.8Details δ1 Lyr A Mass ± 0.1 M ☉ [ 4] ± 0.50 M ☉ [ 8] +0.68 [ 9] M ☉ Luminosity 838[ 6] L ☉ Luminosity (bolometric) 3,620[ 8] L ☉ Surface gravity (log g )± 0.032[ 10] cgs Temperature 20,350[ 8] K Metallicity [Fe/H] −0.05[ 6] dex Rotational velocity (v sin i )± 10[ 10] Age ± 2.2[ 4] +9 [ 9] Myr Other designations Delta1 Lyr , 11 Lyrae , NSV 11504BD +36°3307GC 25934HD 175426HIP 92728HR 7131SAO 67537WDS J18537+3658AGSC 02650-02146[ 11] Database references SIMBAD data
Delta1 Lyrae , its name Latinized from δ1 Lyrae, is a binary star system in the northern constellation of Lyra . It is dimly visible to the naked eye at night with a combined apparent visual magnitude of 5.56.[ 2] light years from the Sun based on parallax ,[ 1] radial velocity of −26 km/s.[ 5] O. J. Eggen originally included this as a candidate member of the proposed Delta Lyrae cluster .[ 12]
The variable radial velocity of this star was discovered from photographic plates taken at the Yerkes Observatory in 1904.[ 13] orbital elements was computed by Frank Craig Jordan in 1916.[ 14] spectroscopic binary with an orbital period of 88.4 days and an eccentricity (ovalness) of 0.37.[ 7]
The visible component of the pair has a blue-white hue with a stellar classification of B2.5V,[ 3] [ 4] B-type main-sequence star undergoing core hydrogen fusion . It is a few million years old with a relatively high rotation rate and around 7–8 times the mass of the Sun. The star is radiating about 3,620[ 8] photosphere at an effective temperature of 20,350 K.[ 8]
There is a magnitude 9.93 visual companion at an angular separation of arcseconds position angle of 20°, as of 2012. This component was discovered by William Herschel.[ 15] evolved giant star with a class of K2III at a distance of around 1,760 light years.[ 16]
^ a b c d e f Brown, A. G. A. ; et al. (Gaia collaboration ) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties" . Astronomy & Astrophysics 616 . A1. arXiv :1804.09365 Bibcode :2018A&A...616A...1G doi :10.1051/0004-6361/201833051 Gaia DR2 record for this source at VizieR .^ a b c d Guetter, H. H. (October 1974), "UBV photometry of 180 early-type stars", Publications of the Astronomical Society of the Pacific , 86 : 795– 797, Bibcode :1974PASP...86..795G , doi :10.1086/129675 ^ a b Guetter, Harry H. (April 1968), "Spectral classification of 239 early-type stars", Publications of the Astronomical Society of the Pacific , 80 (473): 197, Bibcode :1968PASP...80..197G , doi :10.1086/128611 S2CID 121565803 . ^ a b c d Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190– 200, arXiv :1007.4883 Bibcode :2011MNRAS.410..190T , doi :10.1111/j.1365-2966.2010.17434.x S2CID 118629873 . ^ a b Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Carnegie Institute Washington D.C. Publication , Carnegie Institution of Washington , Bibcode :1953GCRV..C......0W . ^ a b c 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 . ^ a b Richardson, E. H.; McKellar, A. (1957), "Redetermination of the spectrographic orbit of delta1 Lyrae", Publ. Dominion Astrophys. Obs. , 10 : 407– 413, Bibcode :1958PDAO...10..407R . , p. 412 ^ a b c d e Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten , 331 (4): 349, arXiv :1003.2335 Bibcode :2010AN....331..349H , doi :10.1002/asna.200911355 , S2CID 111387483 . ^ a b Gullikson, Kevin; et al. (July 26, 2016), "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars", The Astronomical Journal , 152 (2): 40– 53, arXiv :1604.06456 Bibcode :2016AJ....152...40G , doi :10.3847/0004-6256/152/2/40 S2CID 119179065 . ^ a b Huang, W.; Gies, D. R. (August 2008), "Stellar Rotation in Field and Cluster B Stars", The Astrophysical Journal , 683 (2): 1045– 1051, arXiv :0805.2133 Bibcode :2008ApJ...683.1045H , doi :10.1086/590106 , S2CID 18926523 . ^ "del01 Lyr" . SIMBAD Centre de données astronomiques de Strasbourg . Retrieved 2021-01-23 .{{cite web }}: CS1 maint: postscript (link )^ Eggen, O. J. (July 1983), "Concentrations in the Local Association- II. The northern concentrations including the alf Per, Pleiades, M 34 and del LYR clusters.", Monthly Notices of the Royal Astronomical Society , 204 : 391– 403, Bibcode :1983MNRAS.204..391E , doi :10.1093/mnras/204.2.391 ^ Frost, E. B.; Adams, W. S. (1904), "Observations with the Bruce spectrograph", The Astrophysical Journal , 19 : 352, Bibcode :1904ApJ....19..350F , doi :10.1086/141124 ^ Jordan, Frank Craig (1916), "The orbit of [delta]1 Lyrae", Publications of the Allegheny Observatory of the University of Pittsburgh , 3 (14): 119– 124, Bibcode :1916PAllO...3..119J . ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal , 122 (6): 3466– 3471, Bibcode :2001AJ....122.3466M , doi :10.1086/323920 ^ "BD+36 3308" . SIMBAD Centre de données astronomiques de Strasbourg . Retrieved 2021-01-23 .{{cite web }}: CS1 maint: postscript (link )
