Lambda Ursae Majoris

{{Starbox begin

| name=Lambda Ursae Majoris

}}

{{Starbox image

| image ={{Location map|100x100

|AlternativeMap=Ursa Major IAU.svg

|caption=

|alt=Diagram showing star positions and boundaries of the Ursa Major constellation and its surroundings

|width=320

|lat=45.85 |long=59.7

|mark=Cercle rouge 100%.svg | marksize=12

|float=center

}}| caption=Location of λ Ursae Majoris (circled)

}}

{{Starbox observe

| epoch = J2000

| ra = {{RA|10|17|05.78287}}

| dec = {{DEC|+42|54|51.6808}}

| appmag_v = +3.45

| constell = Ursa Major

}}

{{Starbox character

| class = A2 IV

| b-v = +0.03

| u-b = +0.06

| variable =

}}

{{Starbox astrometry

| radial_v = +18.1

| prop_mo_ra = –180.65

| prop_mo_dec = –46.07

| parallax = 23.72

| p_error = 0.78

| parallax_footnote =

| absmag_v = +0.10

}}

{{Starbox detail

| mass = 2.11

| radius = 2.3

| luminosity = 37

| temperature = {{Val|9247|314|fmt=commas}}

| metal_fe = +0.20

| rotation =

| rotational_velocity = 50

| gravity ={{Val|3.76|0.14}}

| age_myr = 380

}}

{{Starbox catalog

| names = 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.

}}

{{Starbox reference

|Simbad=lam+UMa

}}

Lambda Ursae Majoris (λ Ursae Majoris, abbreviated Lambda UMa, λ UMa), formally named Tania Borealis {{IPAc-en|'|t|ei|n|i|@|_|,|b|Q|r|i|'|æ|l|I|s}},{{cite book

|last1=Kunitzsch |first1=Paul

|last2=Smart |first2=Tim

|date = 2006 |edition = 2nd rev.

|title = A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations

|publisher = Sky Pub |location = Cambridge, Massachusetts

|isbn = 978-1-931559-44-7

}}{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/IAU-CSN.txt | title=IAU Catalog of Star Names |accessdate=28 July 2016}} is a star in the northern circumpolar constellation of Ursa Major.

Properties

This star has an apparent visual magnitude of +3.45, 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 {{Convert|138|ly|pc|abbr=off|lk=on}} with a 4% margin of error. The stellar classification of Lambda Ursae Majoris is A2 IV, with the luminosity class of 'IV' indicating that, after 410 million years 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. This energy is being emitted from the star's outer atmosphere at an effective temperature of 9,280 K, giving it the characteristic white-hot glow of an A-type star.

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 {{transl|ar|Al Fiḳrah al Thānia}} 'the Second Spring (of the Gazelle)'.[https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Ursa_Major*.html Richard Hinckley Allen :Star Names — Their Lore and Meaning - Ursa Major, the Greater Bear] and Borealis (originally borealisPiazzi, G., The Palermo Catalogue, Palermo, 1814.) is Latin for 'the north side'. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN){{cite web | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN)|accessdate=22 May 2016}} to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/WGSN_bulletin1.pdf | title=Bulletin of the IAU Working Group on Star Names, No. 1 |accessdate=28 July 2016}} included a table of the first two batches of names approved by the WGSN; which included Tania Borealis for this star.

In Chinese, {{lang|zh|三台}} ({{lang|zh-Latn|Sān Tái}}), 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 {{lang|zh|中台一}} ({{lang|zh-Latn|Zhōng Tái yī}}, {{langx|en|Star of First Middle Step}}).{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0606/ap060621.html (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 21 日] {{Webarchive|url=https://web.archive.org/web/20160303180027/http://aeea.nmns.edu.tw/2006/0606/ap060621.html |date=2016-03-03 }}

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}}

Ursae Majoris, Lambda

Category:Ursa Major

Category:A-type subgiants

Category:Durchmusterung objects