[vsnet-alert 7434] Re: sctv385 outburst?

[Brian Skiff <Brian.Skiff@lowell.edu>]

     No, even without looking at it, one can be pretty certain there is
nothing unusual going on with V385 Sct.  You quote what is presumably the
GCVS range of 13.0-15.0p for the star.  That 'p' indicates photo-blue
magnitudes, roughly standard B.  Now this is a S-type star, very red as
you suggest, and so sure enough it is much brighter in the yellow and red
where you photographs are most sensitive.  Thus your magnitudes are
not unexpected for any stage of the star's variability.  
     Toni:  there is a bunch of stuff about stars, their variability, and
photometry that you clearly do not know but very much need to know in
order to get useful results from your photographs.  Among them are things
about the colors and variability of different types of stars, how a star's
brightness changes as a function of wavelength, etc.  Also you need to
learn a bit about "significant digits" in expressing values such as your
coordinates and magnitudes.  Your position for V385, for instance, is
some 8" from the true position, yet you show the position to 0".01 precision,
giving a false impression of the accuracy of the numbers.  Similarly,
you give the magnitudes to 0.001-mag precision, but then show that the
uncertainties are ~0.5 mag.!  This is not even as good as a simple visual
estimate, and it is thus quite reasonable to doubt the validity of your
measurements---either any one of them or an average.  You show a 'p' after
the magnitudes, suggesting they are the old-style photo-blue magnitudes,
but this is certainly not the case.  The report has no indication of what
system the magnitudes are on, so it is difficult without other information
to decide whether the data are useful at all.
     It is things like this that make all of your reports suspicious.
Since you are obviously enthusiastic, I would recommend strongly that you
seek someone in the Italian amateur-astronomy community who can have a look
at what you are doing and explain how to improve things, and also to give
you reading or other instruction about basic stellar astronomy.  I suspect
part of the problem with your data is placing complete trust in a simple
peice of software that is giving you the coordinates and magnitudes.  But
clearly the data are not as good as you think, and you'll learn a lot of
astronomy (and about how science is done) if you can try to find out why
the results are relatively poor.  Good luck with it.

\Brian

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