Beta Arae (β Ara, β Arae), is the brightest star in the constellation of Ara. It is a very luminous, relatively young, giant or supergiant star with an apparent magnitude of 2.84 and an absolute magnitude of -3.494.[2][7] It is located about 713 light-years from Earth.[6] At this distance, its apparent magnitude is diminished by 0.193 magnitudes due to interstellar extinction between Earth and the star.[8]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ara |
Right ascension | 17h 25m 17.989s[1] |
Declination | −55° 31′ 47.574″[1] |
Apparent magnitude (V) | 2.84[2] |
Characteristics | |
Spectral type | K3 Ib-II[3] |
U−B color index | +1.56[4] |
B−V color index | +1.46[4] |
Astrometry | |
Radial velocity (Rv) | −0.30±0.20[3] km/s |
Proper motion (μ) | RA: −8.51[5] mas/yr Dec.: −25.24[5] mas/yr |
Parallax (π) | 4.5601 ± 0.2077 mas[1] |
Distance | 713+39 −34 ly (218.8+12 −10.4 pc)[6] |
Absolute magnitude (MV) | −3.494[7] |
Details[8] | |
Mass | 5.89±0.07 or 7.89±0.4 M☉ |
Radius | 141.4±6.6 R☉ |
Luminosity | 5,774±535 L☉ |
Surface gravity (log g) | 0.97±0.06 cgs |
Temperature | 4,232±17 K |
Metallicity [Fe/H] | 0.5±0.1 dex |
Rotational velocity (v sin i) | 5.4±1.0[3] km/s |
Age | 50.1±4.4[9] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Characteristics
editThe spectrum of this star matches a stellar classification of K3 Ib-IIa,[3] with the luminosity class notation 'Ib-IIa' indicating that the star lies part way between a higher luminosity bright giant (IIa) and a lower luminosity supergiant (Ib). It has an age estimated at 50 million years, having spent much of its life as a B-type star.[11] Currently, it has expanded to 141 times the Sun's size and is 5,800 times more energetic.[8] Beta Arae is radiating energy from its outer envelope at an effective temperature of 4,200 K, which causes it to take on the orange hue of a K-type star.[12] This enlarged star appears to be rotating slowly with a projected rotational velocity of about 5 km/s.[3] The abundance of elements other than hydrogen and helium, its metallicity, is more than three times that of the Sun.[3][a]
Nomenclature
editBeta Arae is the star's Bayer designation. Other designations include HD 157244 (from the Henry Draper Catalogue), HIP 85258 (from the Hipparcos catalogue) and HR 6461 (from the Bright Star Catalogue).[10]
Rarely, this star is called Vasat-ül-cemre a Turkisation of Arabic وسط الجمر (wasaṭ al-jamar), meaning "middle of the embers."[13] The constellation is named in Arabic المجمرة (al-mijmarah), meaning brazier/incense-burner.[14] In Chinese, 杵 (Chǔ), meaning Pestle, refers to an asterism of β, σ and α Arae.[15] The Chinese name for β Arae is 杵三 (Chǔ sān, English: the Third Star of Pestle.)[16]
Notes
edit- ^ The abundance is estimated by taking [Fe/H] to the power of ten:
10[Fe/H] = 10+0.5 = 3.1
References
edit- ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b Wielen, R.; et al. (1999). "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions". Veröff. Astron. Rechen-Inst. Heidelb. 35 (35). Astronomisches Rechen-Institut Heidelberg: 1. Bibcode:1999VeARI..35....1W.
- ^ a b c d e f De Medeiros, J. R.; et al. (November 2002). "A catalog of rotational and radial velocities for evolved stars. II. Ib supergiant stars". Astronomy and Astrophysics. 395: 97–98. arXiv:1312.3474. Bibcode:2002A&A...395...97D. doi:10.1051/0004-6361:20021214.
- ^ a b Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode:1966CoLPL...4...99J.
- ^ a b van Leeuwen, F. (November 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 Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.; Demleitner, M.; Andrae, R. (2021-03-01). "Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3". The Astronomical Journal. 161 (3): 147. arXiv:2012.05220. Bibcode:2021AJ....161..147B. doi:10.3847/1538-3881/abd806. ISSN 0004-6256. Data about this star can be seen here.
- ^ a b Cassatella, A.; Altamore, A.; Badiali, M.; Cardini, D. (2001). "On the Wilson-Bappu relationship in the Mg II k line". Astronomy and Astrophysics. 374 (3): 1085–1091. arXiv:astro-ph/0106070. Bibcode:2001A&A...374.1085C. doi:10.1051/0004-6361:20010816. S2CID 16286422.
- ^ a b c Soubiran, 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. ISSN 0004-6361. Beta Arae's database entry at VizieR.
- ^ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873.
{{cite journal}}
: CS1 maint: unflagged free DOI (link) - ^ a b "bet Ara -- Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2012-01-15.
- ^ "Beta Arae". stars.astro.illinois.edu. Retrieved 2024-05-22.
- ^ "The Colour of Stars". Australia Telescope, Outreach and Education. Commonwealth Scientific and Industrial Research Organisation. December 21, 2004. Archived from the original on 2012-03-18. Retrieved 2012-01-16.
- ^ "YILDIZ ADLARI SÖZLÜĞÜ" [Glossary of Star Names - V]. Mustafa Pultar (in Turkish). Retrieved 2020-03-04.
- ^ "Ara". Google. Archived from the original on 2020-07-26. Retrieved 2020-03-04.
- ^ 陳久金 (2005). 中國星座神話 [Chinese horoscope myth] (in Chinese). Wunan Book Publishing Co. ISBN 978-986-7332-25-7.
- ^ "天文教育資訊網". AEEA (Activities of Exhibition and Education in Astronomy) (in Chinese). 2006-07-01. Retrieved 2020-03-04.
External links
edit- Kaler, James B., "BETA ARA (Beta Arae)", Stars, University of Illinois, retrieved 2012-01-15
- HR 6461
- Image Beta Arae