How to classify variable stars?

Technology VSX
1

Hello everyone.
When submitting variable stars to VSX, when do we classify a variable star as AM Her type, and when do we classify it as CV?
How do we distinguish between them?

Best regards,
Jiashuo Zhang

2

AM type belongs to the very diverse CV zoo. I suspect that spectral analysis is often required to differentiate of CV types.

Short description of types you would find here, and there is the opportunity with CHOICE course now.

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3

AM is a subtype of CV, so all AM stars are CVs.
Some of the things that support the AM classification are:

  • a large number of X-ray detections
  • a large amplitude
  • showing alternating bright and faint states
  • a redder color than the typical CV, because their companions are red dwarfs
  • the presence of a moderate infrared excess, that can be seen in the W1-W2 WISE colors
  • and a double maxima/minima light curve when folded with the orbital period.

They may or may not show eclipses.

Cheers,
Sebastian

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