Delta Boötis
  | |
| Observation data EpochJ2000EquinoxJ2000 | |
|---|---|
| Constellation | Boötes |
| BD+33 2561 | |
| Right ascension | 15h15m30.16282s[1] |
| Declination | +33° 18′ 53.3925″[1] |
| Apparent magnitude(V) | 3.482[2] |
| BD+33 2562 | |
| Right ascension | 15h15m38.34898s[3] |
| Declination | +33° 19′ 15.3187″[3] |
| Apparent magnitude(V) | 7.81[4] |
| Characteristics | |
| BD+33 2561 | |
| Spectral type | G8 III[5] |
| U−Bcolor index | +0.656[2]/ |
| B−Vcolor index | +0.951[2]/ |
| BD+33 2562 | |
| Spectral type | G0 V[4] |
| U−Bcolor index | +0.02[4] |
| B−Vcolor index | +0.59[4] |
| Astrometry | |
| BD+33 2561 | |
| Radial velocity(Rv) | −12.29±0.16[6]km/s |
| Proper motion(μ) | RA:+84.383mas/yr[1] Dec.:−111.591mas/yr[1] |
| Parallax(π) | 27.0746 ± 0.1256mas[1] |
| Distance | 120.5 ± 0.6ly (36.9 ± 0.2pc) |
| Absolute magnitude(MV) | +0.700[7] |
| BD+33 2562 | |
| Radial velocity(Rv) | −11.83±0.18[3]km/s |
| Proper motion(μ) | RA:+82.776[3]mas/yr Dec.:–110.040[3]mas/yr |
| Parallax(π) | 27.0648 ± 0.0307mas[3] |
| Distance | 120.5 ± 0.1ly (36.95 ± 0.04pc) |
| Details | |
| BD+33 2561 | |
| Mass | 1.5[8]M☉ |
| Radius | 11.43±0.07[9]R☉ |
| Luminosity | 58.1[10]L☉ |
| Surface gravity(logg) | 2.38±0.09[10]cgs |
| Temperature | 4,810±30[10]K |
| Metallicity[Fe/H] | −0.35±0.03[10]dex |
| Rotational velocity(vsini) | 3.6[11]km/s |
| BD+33 2562 | |
| Mass | 0.98[8]M☉ |
| Radius | 0.91±0.02[3]R☉ |
| Luminosity | 0.87[8]L☉ |
| Temperature | 5,812±67[8]K |
| Age | 3.09[8]Gyr |
| Other designations | |
| A:δ Boo,49 Boötis,BD+33 2561,FK5563,HD135722,HIP74666,HR5681,SAO64589[12] | |
| B:BD+33 2562,HIP74674,SAO64591[13] | |
| Database references | |
| SIMBAD | data |
| SIMBAD | data |
Delta Boötis,Latinizedfrom δ Boötis, is adouble starin the northernconstellationofBoötes,forming the easternmost member of the constellation's kite-shapedasterismof brighter stars.[14]Based uponparallaxmeasurements, it is located at a distance of approximately 120.5light-years(36.9parsecs) from theEarth.[1]This star is sometimes calledPrinceps/ˈprɪnsɛps/,[15]meaningprinceorprimeinLatin.The origin of this name is unclear, although it usually appears in anastrologicalcontext.[16][17]Theapparent visual magnitudeof this star is 3.5,[2]making it visible to the naked eyeeven during a Full Moon.The magnitude 7.81[4]companion can be viewed in binoculars or a small telescope.[14]
InChinese,Thất công(Qī Gōng), meaningSeven Excellencies,refers to an asterism consisting of δ Boötis,42 Herculis,τ Herculis,φ Herculis,χ Herculis,ν1Boötisandμ1Boötis.[18]Consequently, theChinese namefor δ Boötis itself isThất công thất(Qī Gōng qī,English:the Seventh Star of Seven Excellencies.)[19]
Properties
[edit]
This system consists of a pair of stars located in physical proximity to each other and sharing a similar motion through space, suggesting that they may form abinary starsystem. Based upon their angular separation and their distance, they have aprojected separationof 3,800Astronomical Units(AU). If they are gravitationally bound to each other, theorbital periodof the system would be at least 120,000 years.[20]
The brighter member of the pair has astellar classificationof G8 III,[5]indicating that it has exhausted the supply of hydrogen at its core andevolvedinto agiant star.It now has a radius more than eleven times the radius of the Sun.[9]Compared to theSun,this star appears deficient in elements other than hydrogen and helium—what astronomers term the star'smetallicity.The outer envelope of this star has aneffective temperatureof 4,810 K,[10]which is what gives it the characteristic yellow hue of aG-type star.[21]
The secondary component has a stellar classification of G0 V,[4]which suggests it is amain sequencestar that may be similar in physical properties to the Sun. The apparent visual magnitude of this star is 7.81,[4]making it much less luminous than the primary component.[22]
References
[edit]- ^abcdeVallenari, A.; et al. (Gaia collaboration) (2023)."GaiaData 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.S2CID244398875. Gaia DR3 record for this sourceatVizieR.
- ^abcdJennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants.",Monthly Notices of the Royal Astronomical Society,172(3): 667–679,Bibcode:1975MNRAS.172..667J,doi:10.1093/mnras/172.3.667
- ^abcdefgBrown, 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.
- ^abcdefgTolbert, Charles Ray (May 1964), "A UBV Study of 94 Wide Visual Binaries",Astrophysical Journal,139:1105,Bibcode:1964ApJ...139.1105T,doi:10.1086/147852
- ^abTsvetkov, A. S.; Popov, A. V.; Smirnov, A. A. (January 2008), "Inaccuracies in the spectral classification of stars from the Tycho-2 Spectral Type Catalogue",Astronomy Letters,34(1): 17–27,Bibcode:2008AstL...34...17T,doi:10.1134/S1063773708010039,S2CID119468042
- ^Soubiran, C.; et al. (2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants",Astronomy and Astrophysics,480(1): 91–101,arXiv:0712.1370,Bibcode:2008A&A...480...91S,doi:10.1051/0004-6361:20078788,S2CID16602121.
- ^Böhm-Vitense, Erika; et al. (December 2000), "Ultraviolet Emission Lines in BA and Non-BA Giants",The Astrophysical Journal,545(2): 992–999,Bibcode:2000ApJ...545..992B,doi:10.1086/317850.
- ^abcdeLuck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants",Astronomical Journal,150(3), 88,arXiv:1507.01466,Bibcode:2015AJ....150...88L,doi:10.1088/0004-6256/150/3/88,S2CID118505114.
- ^abBaines, Ellyn K.; Thomas Armstrong, J.; Clark, James H.; Gorney, Jim; Hutter, Donald J.; Jorgensen, Anders M.; Kyte, Casey; Mozurkewich, David; Nisley, Ishara; Sanborn, Jason; Schmitt, Henrique R.; Van Belle, Gerard T. (2021), "Angular Diameters and Fundamental Parameters of Forty-four Stars from the Navy Precision Optical Interferometer",The Astronomical Journal,162(5): 198,arXiv:2211.09030,Bibcode:2021AJ....162..198B,doi:10.3847/1538-3881/ac2431
- ^abcdeSoubiran, C.; Creevey, O. L.; Lagarde, N.; Brouillet, N.; Jofré, P.; Casamiquela, L.; Heiter, U.; Aguilera-Gómez, C.; Vitali, S.; Worley, C.; de Brito Silva, D. (2024-02-01), "Gaia FGK benchmark stars: Fundamental Teff and log g of the third version",Astronomy and Astrophysics,682:A145,Bibcode:2024A&A...682A.145S,doi:10.1051/0004-6361/202347136,ISSN0004-6361Delta Boo's database entryatVizieR.
- ^Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity",The Astronomical Journal,135(1): 209–231,Bibcode:2008AJ....135..209M,doi:10.1088/0004-6256/135/1/209
- ^ab"del Boo".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2021-06-14.
- ^"BD+33 2562".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2021-06-14.
- ^abEnglish, Neil (May 14, 2014),Grab 'n' Go Astronomy,Springer New York, p. 214,Bibcode:2014gnga.book.....E,ISBN9781493908264.
- ^"princeps".Oxford English Dictionary(Online ed.).Oxford University Press.(Subscription orparticipating institution membershiprequired.)
- ^Robson, Vivian E. (2005),The Fixed Stars and Constellations in Astrology,Astrology Center of America, p. 112,ISBN1-933303-13-1
- ^"Princeps – Constellations of Words".Retrieved2022-10-28.
- ^(in Chinese)Trung quốc tinh tọa thần thoại,written by trần cửu kim. Published by đài loan thư phòng xuất bản hữu hạn công tư, 2005,ISBN978-986-7332-25-7.
- ^(in Chinese)AEEA (Activities of Exhibition and Education in Astronomy) thiên văn giáo dục tư tấn võng 2006 niên 6 nguyệt 26 nhật
- ^Kaler, James B.,"DELTA BOO (Delta Bootis)",Stars,University of Illinois,retrieved2012-01-05
- ^"The Colour of Stars",Australia Telescope, Outreach and Education,Commonwealth Scientific and Industrial Research Organisation,December 21, 2004, archived fromthe originalon 2012-03-18,retrieved2012-01-16
- ^The actual brightness ratio is given by 2.512Δm,where Δmis the difference in magnitude. For this pair, Δm= –4.33, so the ratio is 2.512−4.33= 0.019. Hence the secondary component is 1.9% as bright as the primary.
