Xi Boötis
  Location of ξ Boötis (circled) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 51m 23.37993s[1] |
| Declination | +19° 06′ 01.6994″[1] |
| Apparent magnitude (V) | 4.675 + 6.816[2] |
| Characteristics | |
| Spectral type | G8 Ve + K4 Ve[3] |
| B−V color index | 0.725/1.165[2] |
| Variable type | BY Dra[4] |
| Astrometry | |
| ξ Boo A | |
| Radial velocity (Rv) | +1.59±0.12[1] km/s |
| Proper motion (μ) | RA: 127.468 mas/yr[1] Dec.: −40.569 mas/yr[1] |
| Parallax (π) | 148.0695±0.1317 mas[1] |
| Distance | 22.03 ± 0.02 ly (6.754 ± 0.006 pc) |
| Absolute magnitude (MV) | 5.54±0.007[5] |
| ξ Boo B | |
| Radial velocity (Rv) | +2.31±0.13[6] km/s |
| Proper motion (μ) | RA: 133.376 mas/yr[6] Dec.: −182.059 mas/yr[6] |
| Parallax (π) | 148.1793 ± 0.0546 mas[6] |
| Distance | 22.011 ± 0.008 ly (6.749 ± 0.002 pc) |
| Orbit[7] | |
| Companion | Xi Boo B |
| Period (P) | 151.505±0.170 yr |
| Semi-major axis (a) | 4.9044±0.0027″ |
| Eccentricity (e) | 0.5117±0.0006 |
| Inclination (i) | 140.037±0.095° |
| Longitude of the node (Ω) | 168.100±0.164° |
| Periastron epoch (T) | 1,909.361±0.024 |
| Argument of periastron (ω) (secondary) | 23.917±0.214° |
| Details | |
| ξ Boo A | |
| Mass | 0.88±0.03[8] M☉ |
| Radius | 0.817±0.007[8] R☉ |
| Luminosity | 0.562±0.036[8] L☉ |
| Surface gravity (log g) | 4.561±0.017[8] cgs |
| Temperature | 5,545±92[8] K |
| Metallicity [Fe/H] | −0.10±0.04[8] dex |
| Rotation | 6.2 d[9] |
| Age | 200[10] Myr |
| ξ Boo B | |
| Mass | 0.66±0.07[11] M☉ |
| Radius | 0.61[9] R☉ |
| Luminosity (visual, LV) | 0.061 L☉ |
| Temperature | 4,350±150[11] K |
| Rotation | 11.5[9] d |
| Other designations | |
| ξ Boo, 37 Boötis, BD+19°2870, GC 19991, HD 131156, HIP 72659, HR 5544, SAO 101250, WDS J14514+1906[12] | |
| Database references | |
| SIMBAD | The system |
| A | |
| B | |
| ARICNS | data |
Xi Boötis is a binary star[11] system in the northern constellation of Boötes. Its name is a Bayer designation that is Latinised from ξ Boötis, and abbreviated Xi Boo or ξ Boo. This is the nearest visible star in the constellation Boötes. The brighter, primary component of the pair has a typical apparent visual magnitude of 4.70, making it visible to the naked eye. Based on parallax measurements, it is located at a distance of 22.0 light-years (6.7 pc) light-years from Earth. The pair are drifting further from the Sun with a radial velocity of +2 km/s.[1]
Properties
[edit]
The primary star in this system is a G-type main-sequence star with a stellar classification of G8 Ve,[3] where the 'e' notation indicates emission lines in the spectrum. It is a BY Draconis variable with an apparent magnitude that varies from +4.52 to +4.67 with a period just over 10 days long. The magnetic activity in the star's chromosphere varies with time, but no activity cycle has been found (as of 2019).[14] It has 88% of the mass and 82% of the radius of the Sun, but shines with just 56% the Sun's luminosity.[8]
The secondary component is a smaller K-type main-sequence star with a class of K4 Ve.[3] It has 66% of the Sun's mass and 61% of the Sun's radius. The star is radiating just 6.1% of the luminosity of the Sun from its photosphere at an effective temperature of 4,350 K.[11] This gives it an apparent visual magnitude of 6.8,[2] which by itself would be a challenge to view with the naked eye. As of 2019, it is located at an angular separation of 5.20″ from the primary, along a position angle of 298°.[15]
The pair follow a wide, highly elliptical orbit around their common barycenter, completing an orbit every 151.5 years. Radial velocity measurements taken of the primary as part of an extrasolar planet search show a linear trend in the velocities that is likely due to the secondary star.[16] The pair can be resolved using a small telescope. The binary system contains two of the closest young solar-type stars to the Sun, with a system age of about 200 million years old.[10]
The primary star, component A, has been identified as a candidate for possessing a Kuiper-like belt,[17] based on infrared observations. The estimated minimum mass of this dust disk is 2.4 times the mass of the Earth's Moon. (Compare to the value of 8.2 lunar masses for the Kuiper belt.)[18]
A necessary condition for the existence of a planet in this system are stable zones where the object can remain in orbit for long intervals. For hypothetical planets in a circular orbit around the individual members of this star system, this maximum orbital radius is computed to be 3.8 AU for the primary and 3.5 AU for the secondary. A planet orbiting outside of both stars would need to be at least 108 AU distant.[19]
References
[edit]- ^ a b c d e f 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 Høg, E.; et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27 – L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
- ^ a b c Levato, H.; Abt, H. A. (August 1978). "Spectral types in the Ursa Major stream". Publications of the Astronomical Society of the Pacific. 90: 429−433. Bibcode:1978PASP...90..429L. doi:10.1086/130352.
- ^ Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. GCVS 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S.
- ^ Park, Sunkyung; et al. (2013). "Wilson-Bappu Effect: Extended to Surface Gravity". The Astronomical Journal. 146 (4): 73. arXiv:1307.0592. Bibcode:2013AJ....146...73P. doi:10.1088/0004-6256/146/4/73. S2CID 119187733.
- ^ a b c 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.
- ^ Wielen, R. (November 1962). "Automatic orbit computation for visual binaries". Astronomical Journal. 67: 599–607. Bibcode:1962AJ.....67..599W. doi:10.1086/108791. The data is from Orbit #3; the solution used by the 6th Washington Double Star catalogue for WDS 14514+1906 Archived 2012-02-03 at the Wayback Machine.
- ^ a b c d e f g Karovicova, I.; et al. (2022). "Fundamental stellar parameters of benchmark stars from CHARA interferometry -- II. Dwarf stars". Astronomy & Astrophysics. 658: A47. arXiv:2109.06203. Bibcode:2022A&A...658A..47K. doi:10.1051/0004-6361/202141833. S2CID 219558406.
- ^ a b c Wood, Brian E.; Linsky, Jeffrey L. (July 2010). "Resolving the ξ Boo Binary with Chandra, and Revealing the Spectral Type Dependence of the Coronal "FIP Effect"". The Astrophysical Journal. 717 (2): 1279–1290. arXiv:1005.3281. Bibcode:2010ApJ...717.1279W. doi:10.1088/0004-637X/717/2/1279. S2CID 53394680.
- ^ a b Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008). "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics". The Astrophysical Journal. 687 (2): 1264–1293. arXiv:0807.1686. Bibcode:2008ApJ...687.1264M. doi:10.1086/591785. S2CID 27151456.
- ^ a b c d Fernandes, J.; et al. (October 1998). "Fundamental stellar parameters for nearby visual binary stars: eta Cas, XI Boo, 70 OPH and 85 Peg. Helium abundance, age and mixing length parameter for low mass stars". Astronomy and Astrophysics. 338: 455–464. Bibcode:1998A&A...338..455F.
- ^ "Xi Boo", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2025-05-31.
- ^ Lockwood, G. W.; et al. (July 2007). "Patterns of Photometric and Chromospheric Variation among Sun-like Stars: A 20 Year Perspective". The Astrophysical Journal Supplement Series. 171 (1): 260–303. arXiv:astro-ph/0703408. Bibcode:2007ApJS..171..260L. doi:10.1086/516752. S2CID 18775739. Retrieved 1 July 2022.
- ^ Finley, Adam J.; et al. (May 2019). "The Effect of Magnetic Variability on Stellar Angular Momentum Loss. II. The Sun, 61 Cygni A, ɛ Eridani, ξ Bootis A, and τ Bootis A". The Astrophysical Journal. 876 (1): 14. arXiv:1903.09871. Bibcode:2019ApJ...876...44F. doi:10.3847/1538-4357/ab12d2. S2CID 85500195. 44.
- ^ Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Retrieved 2015-07-22.
- ^ Howard, Andrew W.; Fulton, Benjamin J. (2016). "Limits on Planetary Companions from Doppler Surveys of Nearby Stars". Publications of the Astronomical Society of the Pacific. 128 (969). 114401. arXiv:1606.03134. Bibcode:2016PASP..128k4401H. doi:10.1088/1538-3873/128/969/114401. S2CID 118503912.
- ^ Hinshaw, Gary (February 3, 1997). Science Requirements Document (PDF). NASA JPL. Archived from the original (PDF) on 2006-05-29. Retrieved 2006-08-10.
- ^ Holmes, E. K.; et al. (2003). "A Survey of Nearby Main-Sequence Stars for Submillimeter Emission". The Astronomical Journal. 125 (6): 3334–3343. Bibcode:2003AJ....125.3334H. doi:10.1086/375202.
- ^ Jaime, Luisa G.; et al. (December 2012). "Regions of dynamical stability for discs and planets in binary stars of the solar neighbourhood". Monthly Notices of the Royal Astronomical Society. 427 (4): 2723–2733. arXiv:1208.2051. Bibcode:2012MNRAS.427.2723J. doi:10.1111/j.1365-2966.2012.21839.x. S2CID 118570249.
