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[10] times the radius of the Sun 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 2.99m to 3.33m.[5]
This is a
spectroscopic binary star system with a companion a mere 0.2
AU from the primary, assuming a distance of 71 parsecs, with an
orbital period of 230 days.[8]
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)'.[15] and Australis (originally australis[16]) is
Latin for 'the south side'. In 2016, the
International Astronomical Union organized a
Working Group on Star Names (WGSN)[17] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[18] included a table of the first two batches of names approved by the WGSN; which included Tania Australis for this star.
^
abJohnson, 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.
^
abSamus, 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.
^
abcdefgMassarotti, 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
^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.
ISBN978-1-931559-44-7.