R Boötis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 37m 11.57616s[2] |
| Declination | 26° 44′ 11.6562″[2] |
| Apparent magnitude (V) | 6.0 - 13.3[3] |
| Characteristics | |
| Spectral type | M4-8e[4] |
| B−V color index | 1.50±0.51[5] |
| Variable type | Mira variable[3][6] |
| Astrometry | |
| Radial velocity (Rv) | −58.0±4.7[7] km/s |
| Proper motion (μ) | RA: –25.537[2] mas/yr Dec.: 11.968[2] mas/yr |
| Parallax (π) | 1.5204 ± 0.0586 mas[2] |
| Distance | 2,150 ± 80 ly (660 ± 30 pc) |
| Details | |
| Mass | 0.86[8] M☉ |
| Radius | 245[9] R☉ |
| Luminosity | 5,900[10] L☉ |
| Surface gravity (log g) | −0.44[8] cgs |
| Temperature | 2,640[8] K |
| Metallicity [Fe/H] | 0.55[8] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
R Boötis is a variable star in the northern constellation of Boötes. The star's brightness varies tremendously, ranging from apparent magnitude 6.0, when it might be faintly visible to the naked eye under very good observing conditions, to 13.3, when a fairly large telescope would be required to see it.[3] The distance to this star is approximately 2,150 light years based on parallax measurements.[2] It is drifting closer with a radial velocity of about −58 km/s.[7]
The variability of this star was discovered by German astronomer F. W. Argelander in 1857.[12] It is classified as a Mira-type pulsating variable that ranges in brightness from magnitude 6.0 down to 13.3 with a period of 223.11 days.[3][6] The stellar classification of the star ranges from M4e to M8e,[4] where the 'e' indicates emission features in the spectrum.
The angular diameter of R Boötis has been measured at 3.45±0.1 mas,[13] which at its estimated distance of 660 parsecs[2] gives a physical size 245 times solar.[9]
References
[edit]- ^ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
- ^ a b c d e f g Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b c d Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
- ^ a b Keenan, Philip C.; et al. (1974). "Revised Catalog of Spectra of Mira Variables of Types ME and Se". Astrophysical Journal Supplement. 28: 271. Bibcode:1974ApJS...28..271K. doi:10.1086/190318.
- ^ 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 VSX (4 January 2010). "R Boötis". AAVSO Website. American Association of Variable Star Observers. Retrieved 26 June 2014.
- ^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35495 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.
- ^ a b c d Anders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A.; Matijevic, G.; Monari, G.; Cantat-Gaudin, T. (2019-08-01). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. ISSN 0004-6361. S2CID 131780028.
- ^ a b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3 ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
- ^ Gaia Collaboration; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; Babusiaux, C.; Bailer-Jones, C. A. L.; Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F. (2018-08-01). "Gaia Data Release 2. Summary of the contents and survey properties". Astronomy and Astrophysics. 616: A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. ISSN 0004-6361.
- ^ "R Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-05-01.
- ^ Isles, J. E.; Saw, D. R. B. (February 1987). "106 Mira Stars, - I. R Ari, R Aur, X Aur, R Boo and S Boo". Journal of the British Astronomical Association. 97 (2): 106–116. Bibcode:1987JBAA...97..106I.
- ^ Richichi, A.; Percheron, I.; Khristoforova, M. (2005-02-01). "CHARM2: An updated Catalog of High Angular Resolution Measurements". Astronomy and Astrophysics. 431: 773–777. doi:10.1051/0004-6361:20042039. ISSN 0004-6361. R Boötis' database entry at VizieR.
