Star in a trinary star system in the constellation Lyra
Theta Lyrae Location of θ Lyrae (circled in red)
Observation dataEpoch J2000.0 Equinox J2000.0 Constellation Lyra Right ascension 19h 16m 22.0951s [ 1] Declination +38° 08′ 01.431″[ 1] Apparent magnitude (V)4.38[ 2] Characteristics Spectral type K0II[ 3] U−Bcolor index +1.23[ 2] B−Vcolor index +1.26[ 2] Astrometry Radial velocity (Rv )± 0.14[ 1] km/s Proper motion (μ)RA: mas /yr [ 1] Dec.: mas /yr [ 1] Parallax (π)4.2005± 0.1053 mas [ 1] Distance +21.9 ly +6.7 pc )[ 4] Absolute magnitude (MV )+0.27 [ 3] Details Radius +1.92 [ 5] R ☉ Luminosity ± 43[ 5] L ☉ Surface gravity (log g )1.93[ 3] cgs Temperature ± 44[ 5] K Metallicity [Fe/H] −0.01[ 3] dex Rotational velocity (v sin i )± 1.4[ 3] Other designations θ Lyrae,21 Lyrae,HR 7314,BD +37°3398,HD 180809,SAO 68065,HIP 94713, GC 26585, IDS 19129+3757,GSC 03121-02287[ 6] Database references SIMBAD data
Theta Lyrae (θ Lyr) is ared giant star in the constellationLyra , approximately 760light years away fromEarth .
Theta Lyrae is an orangebright giant star of thespectral type K0II, which means that it possesses a surface temperature of about 5,000K , and is many times bigger and brighter, yet cooler, than theSun .
BD+37°3399 and BD+37°3399B are respectively 10th- and 11th-magnitude companions, although not at the same distance. BD+37°3399 is agiant star with a spectral type of K2III. It is therefore almost the same temperature as Theta Lyrae.[ 7] [ 8]
^a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023)."Gaia Data Release 3. Summary of the content and survey properties" .Astronomy and Astrophysics .674 : A1.arXiv :2208.00211 Bibcode :2023A&A...674A...1G .doi :10.1051/0004-6361/202243940 S2CID 244398875 . Gaia DR3 record for this source atVizieR .^a b c Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system".Vizier Online Data Catalog .2237 .Bibcode :2002yCat.2237....0D . ^a b c d e Carney, Bruce W.; et al. (March 2008). "Rotation and Macroturbulence in Metal-Poor Field Red Giant and Red Horizontal Branch Stars".The Astronomical Journal .135 (3):892– 906.arXiv :0711.4984 Bibcode :2008AJ....135..892C .doi :10.1088/0004-6256/135/3/892 .S2CID 2756572 . ^ Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.; Demleitner, M.; Andrae, R. (2021)."Estimating Distances from Parallaxes. V. Geometric and Photogeometric Distances to 1.47 Billion Stars in Gaia Early Data Release 3" .The Astronomical Journal .161 (3): 147.arXiv :2012.05220 Bibcode :2021AJ....161..147B .doi :10.3847/1538-3881/abd806 S2CID 228063812 . here .^a b c Baines, Ellyn K.; Clark, James H., III; Schmitt, Henrique R.; Stone, Jordan M.; von Braun, Kaspar (2023-12-01)."33 New Stellar Angular Diameters from the NPOI, and Nearly 180 NPOI Diameters as an Ensemble" .The Astronomical Journal .166 (6): 268.arXiv :2505.23514 Bibcode :2023AJ....166..268B .doi :10.3847/1538-3881/ad08be ISSN 0004-6256 . ^ "* tet Lyr" .SIMBAD Centre de données astronomiques de Strasbourg . RetrievedOctober 15, 2007 .^ "BD+37 3399" .SIMBAD Centre de données astronomiques de Strasbourg . RetrievedOctober 15, 2007 .^ "Simbad Query Result" .SIMBAD Centre de données astronomiques de Strasbourg . RetrievedOctober 15, 2007 .
