18 Boötis
| Observation data EpochJ2000EquinoxJ2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h19m16.27966s[1] |
| Declination | +13° 00′ 15.4859″[1] |
| Apparent magnitude(V) | 5.41[2] |
| Characteristics | |
| Spectral type | F3 V[3] |
| B−Vcolor index | 0.385±0.011[2] |
| Astrometry | |
| Radial velocity(Rv) | −0.40±0.7[2]km/s |
| Proper motion(μ) | RA:+105.273[1]mas/yr Dec.:−31.389[1]mas/yr |
| Parallax(π) | 38.1262 ± 0.1323mas[1] |
| Distance | 85.5 ± 0.3ly (26.23 ± 0.09pc) |
| Absolute magnitude(MV) | 3.33[2] |
| Details | |
| Mass | 1.31[4]M☉ |
| Radius | 1.4[5]R☉ |
| Luminosity | 3.90[2]L☉ |
| Surface gravity(logg) | 4.30[4]cgs |
| Temperature | 6,731±229[4]K |
| Metallicity[Fe/H] | −0.03±0.04[6]dex |
| Rotational velocity(vsini) | 40.5±2.0[7]km/s |
| Age | 1.154[4]Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
18 Boötisis a single[9]starin the northernconstellationofBoötes,[8]located about 85 light years away from the Sun.[1]It is visible to the naked eye as a faint, yellow-white hued star with anapparent visual magnitudeof 5.41.[2]This object is a suspected member of theUrsa Major Moving Group,based on velocity criteria.[10]It has a magnitude 10.84optical companionat anangular separationof163.7″along aposition angleof 219°, as of 2010.[11]
This is anF-type main-sequence starwith astellar classificationof F3 V.[3]Older surveys gave a class of F5 IV,[12]showing theluminosity classof asubgiant star.It shows strong evidence for short-term chromospheric variability, although it is not optically variable.[13]
18 Boötis is an estimated 1.15[4]billion years old and is spinning with aprojected rotational velocityof 40.5 km/s.[7]It has 1.3[4]times themass of the Sunand 1.4[5]times theSun's radius.The star is radiating 3.9[2]times theluminosity of the Sunfrom itsphotosphereat aneffective temperatureof 6,731 K.[4]Aninfrared excesshas been detected that suggests a colddebris diskis orbiting34.9AUfrom the host star with ablackbody temperaturefit of 65 K.[5]
References
[edit]- ^abcdefBrown, A. G. A.;et al. (Gaia collaboration) (August 2018)."GaiaData Release 2: Summary of the contents and survey properties ".Astronomy & Astrophysics.616.A1.arXiv:1804.09365.Bibcode:2018A&A...616A...1G.doi:10.1051/0004-6361/201833051.Gaia DR2 record for this sourceatVizieR.
- ^abcdefgAnderson, 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,S2CID119257644.
- ^abGray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample",The Astronomical Journal,132(1): 161–170,arXiv:astro-ph/0603770,Bibcode:2006AJ....132..161G,doi:10.1086/504637,S2CID119476992.
- ^abcdefgDavid, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets",The Astrophysical Journal,804(2): 146,arXiv:1501.03154,Bibcode:2015ApJ...804..146D,doi:10.1088/0004-637X/804/2/146,S2CID33401607.
- ^abcCotten, Tara H.; Song, Inseok (July 2016), "A Comprehensive Census of Nearby Infrared Excess Stars",The Astrophysical Journal Supplement Series,225(1): 24,arXiv:1606.01134,Bibcode:2016ApJS..225...15C,doi:10.3847/0067-0049/225/1/15,S2CID118438871,15.
- ^Gáspár, András; et al. (2016), "The Correlation between Metallicity and Debris Disk Mass",The Astrophysical Journal,826(2): 171,arXiv:1604.07403,Bibcode:2016ApJ...826..171G,doi:10.3847/0004-637x/826/2/171,S2CID119241004.
- ^abAmmler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?",Astronomy & Astrophysics,542:A116,arXiv:1204.2459,Bibcode:2012A&A...542A.116A,doi:10.1051/0004-6361/201118724,S2CID53666672.
- ^ab"18 Boo".SIMBAD.Centre de données astronomiques de Strasbourg.RetrievedMay 8,2019.
- ^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,S2CID14878976.
- ^Nakajima, Tadashi; Morino, Jun-Ichi (2012), "Potential Members of Stellar Kinematic Groups within 30 pc of the Sun",The Astronomical Journal,143(1): 2,Bibcode:2012AJ....143....2N,doi:10.1088/0004-6256/143/1/2.
- ^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,retrieved2015-07-22.
- ^Eggen, O. J. (1962), "Space-velocity vectors for 3483 stars with proper motion and radial velocity",Royal Observatory Bulletin,51:79,Bibcode:1962RGOB...51...79E.
- ^Rachford, Brian L.; Foight, Dillon R. (June 2009), "Chromospheric Variability in Early F-Type Stars",The Astrophysical Journal,698(1): 786–802,arXiv:0904.1620,Bibcode:2009ApJ...698..786R,doi:10.1088/0004-637X/698/1/786,S2CID693296.
