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Re: [AAVSO-DIS] Question About the Variable Types in the Variable StarIndex

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  • Wolfgang Renz
    Hi Gene ... No, not that I know of. ... Your expectations are not correct ! EB is the general acronym for Eclipsing Binary . But if a var type is meant, its
    Message 1 of 2 , Sep 5 5:00 PM
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      Hi Gene

      > Is there a list of the Variable Type field values in the
      > Variable Star Index?

      No, not that I know of.

      > The reason I'm asking is because some of the eclipsing
      > binaries I'm observing/planning to observe (U Cep, Beta Per,
      > Epsilon Aur) have "EA" for the type and I expected to see "EB."

      Your expectations are not correct !

      EB is the general acronym for "Eclipsing Binary".

      But if a var type is meant, its defined as following:
      EA = EBs of A = Algol subtype.
      EB = EBs of B = beta Lyr subtype.
      EW = EWs of W = W UMa subtype.
      So giving the var type EA for all these EBs is correct.
      Tricky, isn't it ? Sometimes even the experts might not know
      if EB means "Eclipsing Binary" or "EB of beta Lyr subtype".

      > Most also have a forward slash and a second abreviation.
      > I seached for a complete list but couldn't find one. If

      Most var types in the VSX originate from the GCVS.
      These are originally described here:
      http://www.sai.msu.su/gcvs/gcvs/iii/vartype.txt
      http://cdsarc.u-strasbg.fr/viz-bin/getCatFile/w/_Redirect?B/gcvs/vartype.txt

      A short overview of var types by the ATNF:
      http://outreach.atnf.csiro.au/education/senior/astrophysics/variable_types.html
      Short list of var types by the ASSA:
      http://www.assa.org.au/sig/variables/classifications.asp
      Extended summary with light curves (LCs) by the AEOFV:
      http://cdsarc.u-strasbg.fr/afoev/var/typo.htx (french)
      http://cdsarc.u-strasbg.fr/afoev/var/etypo.htx (english)
      and GEA at:
      http://www.astrogea.org/VARIABLE/tipus/index.htm (spanish)
      HIP subset of GCVS var types:
      http://cdsarc.u-strasbg.fr/viz-bin/Cat?I/239#sRM99.1
      http://www.rssd.esa.int/Hipparcos/CATALOGUE_VOL1/sect2_04.pdf
      http://nsted.ipac.caltech.edu/NStED/docs/parhelp/HipVarTypeTable.html


      If a var type is not in the above GCVS lists, its probably specific
      for the paper/catalog that is given in the VXSX references. Some
      of the additionally used var types are e.g. defined here:

      Downes CVcat:
      http://archive.stsci.edu/prepds/cvcat/description.html#type

      Ritter & Kolb RKcat:
      http://heasarc.gsfc.nasa.gov/W3Browse/star-catalog/rittercv.html#type1

      More modern pulsating var types:
      2008CoAst.157..240J - The impact of asteroseismology on the theory
      of stellar evolution - Jeffery, C. S.
      http://adsabs.harvard.edu/abs/2008CoAst.157..240J
      Figure 1: Schematic Hertzsprung-Russell diagram showing the locus of
      major classes of pulsating variable star.

      IAUS 272 on Actives OB stars
      http://www.shelyak.com/dossier.php?id_dossier=50&lang=2

      ...

      Clear skies
      Wolfgang

      --
      Wolfgang Renz, Karlsruhe, Germany
    • Sebasti├ín Otero
      ... The SPB and BCEP descriptions in that webpage are interchanged. The longer period stars are the SPB ones. You can also add DPV s
      Message 2 of 2 , Sep 5 6:51 PM
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        > IAUS 272 on Actives OB stars
        > http://www.shelyak.com/dossier.php?id_dossier=50&lang=2

        The SPB and BCEP descriptions in that webpage are interchanged. The longer
        period stars are the SPB ones.

        You can also add DPV's
        http://arxiv.org/abs/0910.4359v1
        Binary Be stars showing the orbital variability (EA, EB or ELL) superposed
        to a longer term variation (30-40 times longer than the orbital period)
        caused by the periodic formation and dissipation of a disk.

        A couple of YSO (Young Stellar Objects) classes are (and can be defined as):

        EX= EXors or Subfuors, subspecies of the FU class. They are named after EX
        Lupi. They are eruptive T Tauri stars that show brightening episodes of
        several magnitudes in time scales of several months or a few years. They
        possibly represent an intermediate state between normal T Tauri stars and FU
        Ori stars. (Examples: EX Lup, V1118 Ori, V1143 Ori)

        UX= UXors (UX Ori stars). Herbig Ae/Be stars that show irregular variations
        with a wide range of amplitudes from barely detectable to more than 4 mag in
        V. Large-amplitude variability is confined to stars with spectral types
        later than B8. There are two principal components: (1) irregular variations
        on timescales of days around a mean brightness level that changes on a much
        longer timescale (typically years), sometimes in a quasi-cyclic fashion, and
        (2) occasional episodes of deep minima, occurring at irregular intervals but
        more frequently near the low points of the brightness cycles (extracted from
        ref. 0081) (Examples: UX Ori, CQ Tau, BF Ori)

        Cheers,
        Sebastian.
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