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Post Info TOPIC: Lambda Boötis
Blobrana


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RE: Lambda Boötis
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Title: Gaia's view of the lambda Boo star puzzle
Author: Simon J. Murphy, Ernst Paunzen

The evolutionary status of the chemically peculiar class of lambda Boo stars has been intensely debated. It is now agreed that the lambda Boo phenomenon affects A stars of all ages, from star formation to the terminal age main sequence, but the cause of the chemical peculiarity is still a puzzle. We revisit the debate of their ages and temperatures in order to shed light on the phenomenon, using the new parallaxes in Gaia Data Release 1 with existing Hipparcos parallaxes and multicolour photometry. We find that no single formation mechanism is able to explain all the observations, and suggest that there are multiple channels producing lambda Boo spectra. The relative importance of these channels varies with age, temperature and environment.

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Blobrana


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Lambda Boötis (also 19 Boötis, HR 5351, HD 125162, HIP 69732, and SAO 44965) is a magnitude +4.18 white A-type star located ~99 light-years away in the constellation Boötes.

Lambda Boötis is the prototype of a group of rare stars known as Lambda Boötis stars, all of which are dwarf stars with unusually low abundances of metals in their spectra.
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Right ascension 14h 16m 23.019s, Declination +46° 05' 17.90"



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