43 research outputs found

    Spectral Classification; Old and Contemporary

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    Beginning with a historical account of the spectral classification, its refinement through additional criteria is presented. The line strengths and ratios used in two dimensional classifications of each spectral class are described. A parallel classification scheme for metal-poor stars and the standards used for classification are presented. The extension of spectral classification beyond M to L and T and spectroscopic classification criteria relevant to these classes are described. Contemporary methods of classifications based upon different automated approaches are introduced.Comment: To be published in "Principles and Perspectives in Cosmochemistry" Lecture Notes on Kodai School on Synthesis of Elements in Stars: Ed Aruna Goswami & Eswar Reddy, Springer Verlag, 2009, 17 pages, 10 figure

    Gaia early data release 3: summary of the contents and survey properties (Corrigendum)

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    ERRATUMThis article is an erratum for:[https://doi.org/10.1051/0004-6361/202039657]​​​​​​​Instrumentatio

    Gaia Early Data Release 3: the Gaia catalogue of nearby stars

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    Stars and planetary system

    Gaia Early Data Release 3: acceleration of the solar system from Gaia astrometry

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    Stars and planetary system

    Gaia Data Release 3: the extragalactic content

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    Galaxie

    Gaia Data Release 3: reflectance spectra of Solar System small bodies

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    Stars and planetary system

    Gaia Data Release 3: mapping the asymmetric disc of the Milky Way

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    Galaxie

    Gaia early data release 3: structure and properties of the Magellanic Clouds

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    Galaxie

    Gaia Early Data Release 3: the Galactic anticentre

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    Stars and planetary system
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