Astronomy:9 Boötis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Boötes[1] |
| Right ascension | 13h 56m 34.18103s[2] |
| Declination | +27° 29′ 31.4932″[2] |
| Apparent magnitude (V) | 5.02[1] |
| Characteristics | |
| Evolutionary stage | AGB[3] |
| Spectral type | K3 III[4] |
| B−V color index | 1.441±0.005[1] |
| Variable type | suspected irregular[5] |
| Astrometry | |
| Radial velocity (Rv) | −41.07±0.14[1] km/s |
| Proper motion (μ) | RA: +28.154[2] mas/yr Dec.: −48.279[2] mas/yr |
| Parallax (π) | 5.2113 ± 0.1011[2] mas |
| Distance | 630 ± 10 ly (192 ± 4 pc) |
| Absolute magnitude (MV) | −1.23[1] |
| Details | |
| Mass | 3.5±0.5[3] M☉ |
| Radius | 44[2] R☉ |
| Luminosity | 857[2] L☉ |
| Surface gravity (log g) | 1.85[6] cgs |
| Temperature | 4,197[7] K |
| Metallicity [Fe/H] | −0.27[6] dex |
| Rotational velocity (v sin i) | 1.5[7] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
9 Boötis is a single,[9] variable star in the northern constellation of Boötes,[8] located around 630 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 5.0. This object is moving closer to the Earth with a heliocentric radial velocity of −41 km/s.[1]
This is an aging giant star with a stellar classification of K3 III,[4] which indicates it has exhausted the hydrogen at its core and evolved of the main sequence. As a consequence, its outer atmosphere has swollen to 44 times the radius of the Sun.[2] It is a suspected irregular variable that ranges in photographic magnitude from 6.1 down to 6.6.[5][10] 9 Boötis is considered mildly lithium-rich with a moderate level of chromospheric activity.[11] It is radiating 857 times the luminosity of the Sun[2] from its enlarged photosphere at an effective temperature of 4,197 K.[7]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 Charbonnel, C.; Balachandran, S. C. (2000). "The Nature of the lithium rich giants. Mixing episodes on the RGB and early-AGB". Astronomy and Astrophysics 359: 563. Bibcode: 2000A&A...359..563C.
- ↑ 4.0 4.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, ISSN 0067-0049, Bibcode: 1989ApJS...71..245K.
- ↑ 5.0 5.1 Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
- ↑ 6.0 6.1 McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", Astrophysical Journal Supplement Series 74: 1075–1128, doi:10.1086/191527, Bibcode: 1990ApJS...74.1075M.
- ↑ 7.0 7.1 7.2 Rebull, Luisa M. et al. (October 2015), "On Infrared Excesses Associated with Li-rich K Giants", The Astronomical Journal 150 (4): 45, doi:10.1088/0004-6256/150/4/123, 123, Bibcode: 2015AJ....150..123R.
- ↑ 8.0 8.1 "9 Boo". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=9+Boo.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ "NSV 6502", The International Variable Star Index (American Association of Variable Star Observers), https://www.aavso.org/vsx/index.php?view=detail.top&oid=45126, retrieved 2019-04-26.
- ↑ Fekel, Francis C.; Balachandran, Suchitra (February 1993), "Lithium and rapid rotation in chromospherically active single giants", Astrophysical Journal, Part 1 403 (2): 708–721, doi:10.1086/172242, Bibcode: 1993ApJ...403..708F.
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