Lambda Ursae Majoris

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Template:Short description

Lambda Ursae Majoris
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Location of λ Ursae Majoris (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Major
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) +3.45[2]
Characteristics
Spectral type A2 IV[3]
U−B Template:Engvar +0.06[2]
B−V Template:Engvar +0.03[2]
Astrometry
Radial velocity (Rv)+18.1[4] km/s
Proper motion (μ) RA: –180.65[1] mas/yr
Dec.: –46.07[1] mas/yr
Parallax (π)23.72±0.78 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)+0.10[5]
Details
Mass2.11[6] Template:Solar mass
Radius2.3[7] Template:Solar radius
Luminosity37[7] Template:Solar luminosity
Surface gravity (log g)Template:Val[6] cgs
TemperatureTemplate:Val[6] K
Metallicity [Fe/H]+0.20[8] dex
Rotational velocity (v sin i)50[9] km/s
Age380[6] Myr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Tania Borealis, λ Ursae Majoris, λ UMa, Lambda UMa, 33 Ursae Majoris, BD+43 2005, FK5 383, GC 14113, HD 89021, HIP 50372, HR 4033, PPM 51795, SAO 43268.[10]
Database references
SIMBADdata

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Lambda Ursae Majoris (λ Ursae Majoris, abbreviated Lambda UMa, λ UMa), formally named Tania Borealis Template:IPAc-en,[11][12] is a star in the northern circumpolar constellation of Ursa Major.

Properties

This star has an apparent visual magnitude of +3.45,[2] making it one of the brighter members of the constellation. The distance to this star has been measured directly using the parallax technique, which yields a value of roughly Template:Convert with a 4% margin of error. The stellar classification of Lambda Ursae Majoris is A2 IV,[3] with the luminosity class of 'IV' indicating that, after 410 million years[13] on the main sequence, this star is in the process of evolving into a giant star as the supply of hydrogen at its core becomes exhausted. Compared to the Sun it has 240% of the mass and 230% of the Sun's radius, but is radiating 37 times as much luminosity.[7] This energy is being emitted from the star's outer atmosphere at an effective temperature of 9,280 K,[8] giving it the characteristic white-hot glow of an A-type star.[14]

Nomenclature

λ Ursae Majoris (Latinised to Lambda Ursae Majoris) is the star's Bayer designation.

It bore the traditional names Tania (shared with Mu Ursae Majoris) and Tania Borealis. Tania comes from the Arabic phrase Template:Transliteration 'the Second Spring (of the Gazelle)'.[15] and Borealis (originally borealis[16]) is Latin for 'the north 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 Borealis for this star.

In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Three Steps, refers to an asterism consisting of Lambda Ursae Majoris, Iota Ursae Majoris, Kappa Ursae Majoris, Mu Ursae Majoris, Nu Ursae Majoris and Xi Ursae Majoris. Consequently, the Chinese name for Lambda Ursae Majoris itself is Script error: No such module "Lang". (Script error: No such module "Lang"., Template:Langx).[19]

References

Template:Reflist Template:Stars of Ursa Major

  1. ↑ a b c d e Cite error: Invalid <ref> tag; no text was provided for refs named aaa474_2_653
  2. ↑ a b c d Cite error: Invalid <ref> tag; no text was provided for refs named clpl4_99
  3. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named aj74_375
  4. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named rgcrv
  5. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Eggen1998
  6. ↑ a b c d Cite error: Invalid <ref> tag; no text was provided for refs named David2015
  7. ↑ a b c Cite error: Invalid <ref> tag; no text was provided for refs named aass85_3_1015
  8. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named aaa294_2_536
  9. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named aaa463_2_671
  10. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named SIMBAD
  11. ↑ Script error: No such module "citation/CS1".
  12. ↑ Script error: No such module "citation/CS1".
  13. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named apj653_1_675
  14. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named csiro
  15. ↑ Richard Hinckley Allen :Star Names — Their Lore and Meaning - Ursa Major, the Greater Bear
  16. ↑ Piazzi, G., The Palermo Catalogue, Palermo, 1814.
  17. ↑ Script error: No such module "citation/CS1".
  18. ↑ Script error: No such module "citation/CS1".
  19. ↑ Template:In lang (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 21 日 Template:Webarchive
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