Mu Ursae Majoris

Mu Ursae Majoris
	; Location of μ Ursae Majoris (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Ursa Major
Right ascension	10h 22m 19.73976s
Declination	+41° 29′ 58.2691″
Apparent magnitude (V)	+3.06
Characteristics
Evolutionary stage	AGB
Spectral type	M0 IIIab
U−B color index	+1.90
B−V color index	+1.59
Variable type	suspected
Astrometry
Radial velocity (Rv)	−21.30±1.66 km/s
Proper motion (μ)	RA: –81.47 mas/yr ; Dec.: +35.34 mas/yr
Parallax (π)	14.16±0.54 mas
Distance	230 ± 9 ly ; (71 ± 3 pc)
Absolute magnitude (MV)	−1.11±0.083
Orbit
Period (P)	230.089 days
Semi-major axis (a)	0.0028″
Eccentricity (e)	0.061
Inclination (i)	13.6°
Periastron epoch (T)	2425577.030 JD
Argument of periastron (ω); (secondary)	236.4°
Semi-amplitude (K1); (primary)	7.40 km/s
Details
μ UMa A
Mass	6.3 M☉
Radius	75 R☉
Luminosity	977–1,200 L☉
Surface gravity (log g)	1.0 cgs
Temperature	3,899 K
Metallicity [Fe/H]	+0.00 dex
Rotational velocity (v sin i)	7.5 km/s
μ UMa B
Mass	0.96 M☉
Other designations
	Tania Australis, Alkafzah al Thaniyah, μ Ursae Majoris, μ UMa, Mu UMa, 34 Ursae Majoris, BD+42 2115, FK5 386, GC 14232, HD 89758, HIP 50801, HR 4069, PPM 51850, SAO 43310
Database references
SIMBAD	data

Mu Ursae Majoris is a binary star in the constellation of Ursa Major, and possibly makes part of a triple star system. It has the proper name Tania Australis /ˈteɪniə ɔːˈstreɪlɪs/,^[12]^[13] Mu Ursae Majoris it is Bayer designation. An apparent visual magnitude of +3.06^[2] places it among the brighter members of the constellation. Parallax measurements give a distance measurement of roughly 230 light-years (71 parsecs), with a margin of error of 4%.^[1]

Stellar system

Mu Ursae Majoris is an evolved star that is currently in the red giant stage with a stellar classification of M0 IIIab.^[2] It has expanded to 75 times the radius of the Sun^[10] whilst the outer atmosphere has cooled to an effective temperature of 3,899 K,^[6] giving it the orange-red hued glow of an M-type star.^[14] Estimates of the luminosity range from 977^[10]–1,200^[6] times that of the Sun. It is classified as a suspected variable star with a brightness variation from magnitude 2.99^m to 3.33^m.^[5]

This is a spectroscopic binary star system with a companion a mere 0.2 AU from the primary, with an orbital period of 230 days.^[8]

In addition to the inner pair, a proper motion companion has a 99% chance to be related to this system. It has a very low mass of just 0.1 solar masses, and a projected separation of 3,900 astronomical units.^[15]

Nomenclature

μ Ursae Majoris (Latinised to Mu Ursae Majoris) is the star's Bayer designation. It can be abbreviated to abbreviated Mu UMa or μ UMa.

It bore the traditional names Tania (shared with Lambda Ursae Majoris) and Tania Australis. Tania comes from the Arabic phrase Al Fiḳrah al Thānia 'the Second Spring (of the Gazelle)'.^[16] and Australis (originally australis^[17]) is Latin for 'the south side'. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)^[18] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016^[19] included a table of the first two batches of names approved by the WGSN; which included Tania Australis for this star.

In Chinese, 三台 (Sān Tái), meaning Three Steps, refers to an asterism consisting of Mu Ursae Majoris, Iota Ursae Majoris, Kappa Ursae Majoris, Lambda Ursae Majoris, Nu Ursae Majoris and Xi Ursae Majoris. Consequently, the Chinese name for Mu Ursae Majoris itself is 中台二 (Zhōng Tái èr, English: Star of Second Middle Step).^[20]

References

^ ^a ^b ^c ^d ^e ^f van Leeuwen, Floor (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752v1. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Note: see VizieR catalogue I/311.
^ ^a ^b ^c ^d Mallik, Sushma V. (December 1999). "Lithium abundance and mass". Astronomy and Astrophysics. 352: 495–507. Bibcode:1999A&A...352..495M.
^ Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". Astronomical Journal. 104 (1): 275–313. Bibcode:1992AJ....104..275E. doi:10.1086/116239.
^ ^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 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
^ ^a ^b ^c ^d ^e ^f ^g 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.
^ Park, Sunkyung; et al. (2013). "Wilson-Bappu Effect: Extended to Surface Gravity". The Astronomical Journal. 146 (4): 73. arXiv:1307.0592. Bibcode:2013AJ....146...73P. doi:10.1088/0004-6256/146/4/73. S2CID 119187733.
^ ^a ^b Ren, Shulin; Fu, Yanning (2013). "Hipparcos Photocentric Orbits of 72 Single-lined Spectroscopic Binaries". The Astronomical Journal. 145 (3): 81. Bibcode:2013AJ....145...81R. doi:10.1088/0004-6256/145/3/81. S2CID 120199240.
^ ^a ^b Kraicheva, Z.; Popova, E.; Tutukov, A.; Yungelson, L. (July 1980). "Catalogue of physical parameters of spectroscopic binary stars". Bulletin d'Information du Centre de Donnees Stellaires. 19: 71. Bibcode:1980BICDS..19...71K. ISSN 1169-8837.
^ ^a ^b ^c ^d Jorissen, A.; et al. (May 2009). "Spectroscopic binaries among Hipparcos M giants. III. The eccentricity - period diagram and mass-transfer signatures". Astronomy and Astrophysics. 498 (2): 489–500. arXiv:0901.0938. Bibcode:2009A&A...498..489J. doi:10.1051/0004-6361/200810703. S2CID 2754939.
^ Mallik, Sushma V. (October 1998). "Chromospheric activity in cool stars and the lithium abundance". Astronomy and Astrophysics. 338: 623–636. Bibcode:1998A&A...338..623M.
^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
^ "IAU Catalog of Star Names". Retrieved 28 July 2016.
^ "The Colour of Stars". Australia Telescope, Outreach and Education. Commonwealth Scientific and Industrial Research Organisation. December 21, 2004. Archived from the original on March 18, 2012. Retrieved 2012-01-16.
^ Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (January 2022). "Stellar and substellar companions from Gaia EDR3. Proper-motion anomaly and resolved common proper-motion pairs". Astronomy and Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. ISSN 0004-6361.
^ Richard Hinckley Allen. "Star Names — Their Lore and Meaning - Ursa Major, the Greater Bear". Retrieved 2016-08-26.
^ Piazzi, G. (1814). The Palermo Catalogue. Palermo.
^ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
^ "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Retrieved 28 July 2016.
^ "(Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 21 日" (in Chinese). Archived from the original on 2016-03-03. Retrieved 2016-08-26.

[aaa474_2_653-1] ^ ^a ^b ^c ^d ^e ^f van Leeuwen, Floor (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752v1. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Note: see VizieR catalogue I/311.

[aaa352_495-2] Mallik, Sushma V. (December 1999). "Lithium abundance and mass". Astronomy and Astrophysics. 352: 495–507. Bibcode:1999A&A...352..495M.

[Eggen1992-3] Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". Astronomical Journal. 104 (1): 275–313. Bibcode:1992AJ....104..275E. doi:10.1086/116239.

[clpl4_99-4] 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.

[gcvs-5] Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.

[aj135_1_209-6] ^ ^a ^b ^c ^d ^e ^f ^g 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.

[park2013-7] Park, Sunkyung; et al. (2013). "Wilson-Bappu Effect: Extended to Surface Gravity". The Astronomical Journal. 146 (4): 73. arXiv:1307.0592. Bibcode:2013AJ....146...73P. doi:10.1088/0004-6256/146/4/73. S2CID 119187733.

[ren-8] Ren, Shulin; Fu, Yanning (2013). "Hipparcos Photocentric Orbits of 72 Single-lined Spectroscopic Binaries". The Astronomical Journal. 145 (3): 81. Bibcode:2013AJ....145...81R. doi:10.1088/0004-6256/145/3/81. S2CID 120199240.

[kraicheva1980-9] Kraicheva, Z.; Popova, E.; Tutukov, A.; Yungelson, L. (July 1980). "Catalogue of physical parameters of spectroscopic binary stars". Bulletin d'Information du Centre de Donnees Stellaires. 19: 71. Bibcode:1980BICDS..19...71K. ISSN 1169-8837.

[aaa498_2_489-10] Jorissen, A.; et al. (May 2009). "Spectroscopic binaries among Hipparcos M giants. III. The eccentricity - period diagram and mass-transfer signatures". Astronomy and Astrophysics. 498 (2): 489–500. arXiv:0901.0938. Bibcode:2009A&A...498..489J. doi:10.1051/0004-6361/200810703. S2CID 2754939.

[aaa338_623-11] Mallik, Sushma V. (October 1998). "Chromospheric activity in cool stars and the lithium abundance". Astronomy and Astrophysics. 338: 623–636. Bibcode:1998A&A...338..623M.

[Kunitzsch-12] Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.

[IAU-CSN-13] "IAU Catalog of Star Names". Retrieved 28 July 2016.

[csiro-14] "The Colour of Stars". Australia Telescope, Outreach and Education. Commonwealth Scientific and Industrial Research Organisation. December 21, 2004. Archived from the original on March 18, 2012. Retrieved 2012-01-16.

[Kervella2022-15] Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (January 2022). "Stellar and substellar companions from Gaia EDR3. Proper-motion anomaly and resolved common proper-motion pairs". Astronomy and Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. ISSN 0004-6361.

[rhallen1899-16] Richard Hinckley Allen. "Star Names — Their Lore and Meaning - Ursa Major, the Greater Bear". Retrieved 2016-08-26.

[piazzi1814-17] Piazzi, G. (1814). The Palermo Catalogue. Palermo.

[WGSN-18] "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.

[WGSN1-19] "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Retrieved 28 July 2016.

[zh-icon-20] "(Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 21 日" (in Chinese). Archived from the original on 2016-03-03. Retrieved 2016-08-26.

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Mu Ursae Majoris

Stellar system

Nomenclature

References

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