[vsnet-chat 4729] Re: SARVs

[Klaus Bernhard <kl.bernhard@aon.at>]

Hi Stan, John, Sebastian and all,

thanks for your comments.
I couldnt answer until now, because I was on holiday,
but the most things seem to be said now.
Only a few more comments to Stans note (vsnet-chat 4700):

> Harry Williams and I made some measures of SARVs some years ago but, quite
> frankly, the observing methods to be used were not particularly reliable and
> the results were confusing. If you're achieving 1-2% photometry then it's
> hard to be certain about amplitudes of less than 0.1 magnitudes as many of
> these SARV candidates seem to have. We couldn't even confirm the periods on
> some of the more well known of these objects. With target star, comparison
> and check all early M class probably everything was varying. With better
> comparisons and colour transformations the results would probably have been
> better but this wasn't under our control.

I have made the same experiences with comparison stars for red variables.
This is the reason, why I post new variables only to VSNET, if the amplitude
exceeds 0.20 mag. In my note I have meant SARVs in the sense of IBVS 5041,
where various red variables with amplitudes of 0.2-1 mag are described.  

> But since there are some extremely interesting objects
> amongst the larger amplitude SR stars it's frustrating to see the SR
> category used as a sort of 'unclassified' dumping place. Maybe there is a
> case for an unclassified variable type? To my mind SARVs are SARVs and not
> SR stars.

I see now from this note and others, that a preliminary classification "SR", 
which is also used by other groups, can be misleading, even if it is mentioned, 
that other types are possible. 
So I will avoid this description for insufficient studied red variables in future. 

Best wishes,

Klaus Bernhard

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