Theta Lyrae (θ Lyr) is a red giant star in the constellation Lyra, approximately 760 light years away from Earth.
| Observation data Epoch 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−B color index | +1.23[2] |
| B−V color index | +1.26[2] |
| Astrometry | |
| Radial velocity (Rv) | −31.05±0.14[1] km/s |
| Proper motion (μ) | RA: −2.864 mas/yr[1] Dec.: 4.114 mas/yr[1] |
| Parallax (π) | 4.2005±0.1053 mas[1] |
| Distance | 755.9+21.9 −20.2 ly (237.9+6.7 −6.2 pc)[4] |
| Absolute magnitude (MV) | −2.76+0.27 −0.24[3] |
| Details | |
| Radius | 60.31+1.92 −2.99[5] R☉ |
| Luminosity | 1,374±43[5] L☉ |
| Surface gravity (log g) | 1.93[3] cgs |
| Temperature | 4,523±44[5] K |
| Metallicity [Fe/H] | −0.01[3] dex |
| Rotational velocity (v sin i) | 3.6±1.4[3] km/s |
| 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 is an orange bright giant star of the spectral type K0II, which means that it possesses a surface temperature of about 5,000 K, and is many times bigger and brighter, yet cooler, than the Sun.
BD+37°3399 and BD+37°3399B are respectively 10th- and 11th-magnitude companions, although not at the same distance. BD+37°3399 is a giant star with a spectral type of K2III. It is therefore almost the same temperature as Theta Lyrae.[7] BD+37° 3399B is an 11th magnitude star of an unknown spectral type.[8]
References
edit- ^ 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 at VizieR.
- ^ 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. Data about this star can be seen 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. Retrieved October 15, 2007.
- ^ "BD+37 3399". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 15, 2007.
- ^ "Simbad Query Result". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 15, 2007.