Delta Arae

Delta Arae
	; δ Arae (lower center) in the Ara Constellation
Observation data; Epoch J2000.0 Equinox J2000.0
Constellation	Ara
Right ascension	17h 31m 05.91272s
Declination	–60° 41′ 01.8522″
Apparent magnitude (V)	3.62
Characteristics
Spectral type	B8 Vn + G8 V
U−B color index	–0.31
B−V color index	–0.10
Astrometry
Radial velocity (Rv)	+10 km/s
Proper motion (μ)	RA: –54.01 mas/ yr ; Dec.: –99.25 mas/ yr
Parallax (π)	16.48 ± 0.34 mas
Distance	198 ± 4 ly ; (61 ± 1 pc)
Absolute magnitude (MV)	−0.31
Details
Mass	3.56 M☉
Radius	3.12 ± 0.15 R☉
Luminosity	214 L☉
Surface gravity (log g)	3.81 ± 0.06 cgs
Temperature	11,962 ± 86 K
Rotational velocity (v sin i)	255 km/s
Age	125 Myr
Other designations
	δ Ara, CPD –60° 6842, FK5 648, HD 158094, HIP 85727, HR 6500, SAO 253945.
Database references
SIMBAD	data

Delta Arae, Latinized from δ Arae, is the Bayer designation for a double star in the southern constellation Ara. It has an apparent visual magnitude of 3.62^[2] and is visible to the naked eye. Based upon an annual parallax of 16.48 mas, it is about 198 light-years (61 parsecs) distant from the Earth.^[1]

Delta Arae is massive B-type main sequence star with a stellar classification of B8 Vn.^[3] The 'n' suffix indicates the absorption lines are spread out broadly because the star is spinning rapidly. It has a projected rotational velocity of 255 km/s, resulting in an equatorial bulge with a radius 13% larger than the polar radius.^[4] It has a magnitude 9.5 companion G-type main sequence star that may form a binary star system with Delta Arae.^[7]

There is a 12th magnitude optical companion located 47.4 arcseconds away along a position angle of 313°.^[9]

Etymology

Delta Arae was known as 龜三 (meaning: "the 3rd (star) of Guī") in traditional Chinese astronomy.^[11]^[12]

Allen erroneously called both Delta and Zeta Arae "Tseen Yin" (天陰).^[13] He probably confused the constellation " Ara" with " Ari", as 天陰 is actually in Aries.^[11]^[12]

References

^ ^a ^b ^c ^d ^e ^f 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 ^c ^d Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode: 1978A&AS...34....1N.
^ ^a ^b Houk, Nancy (1979), "Michigan catalogue of two-dimensional spectral types for the HD stars", Ann Arbor: Dept. Of Astronomy, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
^ ^a ^b ^c van Belle, Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv: 1204.2572, Bibcode: 2012A&ARv..20...51V, doi: 10.1007/s00159-012-0051-2, S2CID 119273474.
^ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode: 1967IAUS...30...57E.
^ ^a ^b Anderson, 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, S2CID 119257644.
^ ^a ^b Shaya, Ed J.; Olling, Rob P. (January 2011), "Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue", The Astrophysical Journal Supplement, 192 (1): 2, arXiv: 1007.0425, Bibcode: 2011ApJS..192....2S, doi: 10.1088/0067-0049/192/1/2, S2CID 119226823.
^ ^a ^b ^c Fitzpatrick, E. L.; Massa, D. (March 2005), "Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry", The Astronomical Journal, 129 (3): 1642–1662, arXiv: astro-ph/0412542, Bibcode: 2005AJ....129.1642F, doi: 10.1086/427855, S2CID 119512018.
^ ^a ^b Ehrenreich, D.; et al. (November 2010), "Deep infrared imaging of close companions to austral A- and F-type stars", Astronomy and Astrophysics, 523: A73, arXiv: 1007.0002, Bibcode: 2010A&A...523A..73E, doi: 10.1051/0004-6361/201014763, S2CID 54913363.
^ "del Ara". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-27.{{ cite web}}: CS1 maint: postscript ( link)
^ ^a ^b Chevalier, S., and Tsuchihashi, P., (1911): "Catalogue d'Étoiles fixes, observés a Pekin sous l' Empereur Kien Long (Qianlong (Chien-Lung)), XVIII^e siecle", Annales de l'Observatoire Astronomique de Zô-Sé.
^ ^a ^b 伊世同 (Yi Shi Tong) (1981): 『中西対照恒星図表』科学出版社.(in Chinese)
^ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 64. ISBN 0-486-21079-0.

External links

[aaa474_2_653-1] ^ ^a ^b ^c ^d ^e ^f 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.

[aass34_1-2] Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode: 1978A&AS...34....1N.

[houk1979-3] Houk, Nancy (1979), "Michigan catalogue of two-dimensional spectral types for the HD stars", Ann Arbor: Dept. Of Astronomy, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.

[aar20_1_51-4] van Belle, Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv: 1204.2572, Bibcode: 2012A&ARv..20...51V, doi: 10.1007/s00159-012-0051-2, S2CID 119273474.

[rgcrv-5] Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode: 1967IAUS...30...57E.

[Anderson2012-6] Anderson, 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, S2CID 119257644.

[apjss192_1_2-7] Shaya, Ed J.; Olling, Rob P. (January 2011), "Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue", The Astrophysical Journal Supplement, 192 (1): 2, arXiv: 1007.0425, Bibcode: 2011ApJS..192....2S, doi: 10.1088/0067-0049/192/1/2, S2CID 119226823.

[aj129_3_1642-8] Fitzpatrick, E. L.; Massa, D. (March 2005), "Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry", The Astronomical Journal, 129 (3): 1642–1662, arXiv: astro-ph/0412542, Bibcode: 2005AJ....129.1642F, doi: 10.1086/427855, S2CID 119512018.

[aaa523_A73-9] Ehrenreich, D.; et al. (November 2010), "Deep infrared imaging of close companions to austral A- and F-type stars", Astronomy and Astrophysics, 523: A73, arXiv: 1007.0002, Bibcode: 2010A&A...523A..73E, doi: 10.1051/0004-6361/201014763, S2CID 54913363.

[SIMBAD-10] "del Ara". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-27.{{ cite web}}: CS1 maint: postscript ( link)

[ChT-11] Chevalier, S., and Tsuchihashi, P., (1911): "Catalogue d'Étoiles fixes, observés a Pekin sous l' Empereur Kien Long (Qianlong (Chien-Lung)), XVIII^e siecle", Annales de l'Observatoire Astronomique de Zô-Sé.

[YST-12] 伊世同 (Yi Shi Tong) (1981): 『中西対照恒星図表』科学出版社.(in Chinese)

[allen-13] Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 64. ISBN 0-486-21079-0.

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Observation data Epoch J2000.0 Equinox J2000.0
δ Arae (lower center) in the Ara Constellation
Constellation	Ara
Right ascension	17^h 31^m 05.91272^s^[1]
Declination	–60° 41′ 01.8522″^[1]
Apparent magnitude (V)	3.62^[2]
Characteristics
Spectral type	B8 Vn^[3] + G8 V^[4]
U−B color index	–0.31^[2]
B−V color index	–0.10^[2]
Astrometry

Radial velocity (R_v)	+10^[5] km/s
Proper motion (μ)	RA: –54.01^[1] mas/ yr Dec.: –99.25^[1] mas/ yr
Parallax (π)	16.48 ± 0.34 mas^[1]
Distance	198 ± 4 ly (61 ± 1 pc)
Absolute magnitude (M_V)	−0.31^[6]

Details

Mass	3.56^[7] `M`_☉
Radius	3.12 ± 0.15^[8] `R`_☉
Luminosity	214^[6] `L`_☉
Surface gravity (log g)	3.81 ± 0.06^[8] cgs
Temperature	11,962 ± 86^[8] K
Rotational velocity (v sin i)	255^[4] km/s
Age	125^[9] Myr

Other designations
δ Ara, CPD –60° 6842, FK5 648, HD 158094, HIP 85727, HR 6500, SAO 253945.^[10]
Database references
SIMBAD	data

Etymology

See also

References

Further reading

External links