39 Boötis is a triple star[3] system located around 224[1] light years away from the Sun in the northern constellation of Boötes.[10] It is visible to the naked eye as a faint, yellow-white hued star with a combined apparent magnitude of 5.68.[2] The system is moving closer to the Earth with a heliocentric radial velocity of −31 km/s.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 49m 41.29265s[1] |
| Declination | +48° 43′ 14.9077″[1] |
| Apparent magnitude (V) | 5.68[2] (6.36 + 6.72)[3] |
| Characteristics | |
| Spectral type | F8V + F7V[4] |
| Astrometry | |
| Radial velocity (Rv) | −30.9±0.3[5] km/s |
| Proper motion (μ) | RA: −77.94[1] mas/yr Dec.: 100.83[1] mas/yr |
| Parallax (π) | 14.58 ± 0.51 mas[1] |
| Distance | 224 ± 8 ly (69 ± 2 pc) |
| Absolute magnitude (MV) | 2.53[6] |
| Orbit[7] | |
| Period (P) | 12.822 d |
| Eccentricity (e) | 0.39 |
| Periastron epoch (T) | 2,422,379.49 JD |
| Argument of periastron (ω) (secondary) | 97.1° |
| Semi-amplitude (K1) (primary) | 58.3 km/s |
| Semi-amplitude (K2) (secondary) | 72.2 km/s |
| Details | |
| 39 Boo A | |
| Mass | 1.29/1.05[8] M☉ |
| Metallicity [Fe/H] | 0.06[9] dex |
| Rotational velocity (v sin i) | 161.0[6] km/s |
| Age | 1.30[9] Gyr |
| 39 Boo B | |
| Mass | 1.25[8] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The magnitude 6.36[3] primary, component A, is actually a double-lined spectroscopic binary system with an orbital period of 12.822 days, an eccentricity of 0.39,[7] and an angular separation of 2.021 mas. It has a combined stellar classification of F8V,[4] matching an F-type main-sequence star, with individual massed of 1.29 and 1.05[8] times the mass of the Sun. Component B is of magnitude 6.72[3] with a class of F7V[4] and 1.25[8] solar masses. The A–B pair have a separation of 2.9″ and a period of 1,347.653 years.[8] This system is a source of X-ray emission with a luminosity of 41.4×1028 erg s−1.[11]
It was a transferred by Jérôme Lalande from Boötes to Quadrans Muralis.[12] Later when the International Astronomical Union officially recognised constellations, Quadrans Muralis became obsolete, so this star was moved back to Boötes.
References
edit- ^ a b c d e f van Leeuwen, F. (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.
- ^ a b 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 c d Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ a b c Abt, Helmut A. (2009). "MK Classifications of Spectroscopic Binaries". The Astrophysical Journal Supplement. 180 (1): 117–18. Bibcode:2009ApJS..180..117A. doi:10.1088/0067-0049/180/1/117. S2CID 122811461.
- ^ a b 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.
- ^ a b Pizzolato, N.; et al. (September 2000). "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases". Astronomy and Astrophysics. 361: 614–628. Bibcode:2000A&A...361..614P.
- ^ a b Pourbaix, D.; et al. (2004). "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits". Astronomy & Astrophysics. 424: 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
- ^ a b c d e Tokovinin, A.; et al. (2008). "Tertiary companions to close spectroscopic binaries". Multiple Stars Across the H-R Diagram, ESO Astrophysics Symposia. Berlin Heidelberg. p. 129. arXiv:astro-ph/0601518. Bibcode:2006yCat..34500681T. doi:10.1051/0004-6361:20054427. ISBN 978-3-540-74744-4.
- ^ a b Casagrande, L.; et al. (June 2011). "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey". Astronomy and Astrophysics. 530: A138. arXiv:1103.4651. Bibcode:2011A&A...530A.138C. doi:10.1051/0004-6361/201016276. S2CID 56118016.
- ^ a b "39 Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved May 12, 2019.
- ^ Pizzolato, N.; et al. (September 2000). "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases". Astronomy and Astrophysics. 361: 614–628. Bibcode:2000A&A...361..614P.
- ^ Smyth, William Henry (1844). A Cycle of Celestial Objects: For the Use of Naval, Military, and Private Astronomers. Vol. 2. London, United Kingdom: John W. Parker. p. 329.