Re: Suspected Variables in TASS data

[Tom Droege <tdroege2@earthlink.net>]

Here I disagree with Arne.  While a professional astronomer running a 
survey cannot look at all the candidates (he is usually too busy writing 
for grants to do much of anything else), an amateur group such as tass 
can.  I have examined a few thousand candidates (from the software) 
already.  I have decided that a hundred or so are probably variable.  This 
in less than a month.

I expect to keep this up for 10 years or so.  I see no problem looking at 
10s of thousands of light curves.  At time goes on, we will develop better 
and better tools.  There are several hundred on the tass list.  some of 
them can be trained to make good decisions while looking at variable star 
data.   I emphasize that the tools will get better over time.  Most of the 
people on the tass list are skilled programmers.  I have worked with such 
for a long time.  When faced with a boring task, they are diverted to 
writing code to automate the process.  We shall see what happens when I try 
to get people to process stars.

One of the reasons that I want to keep the raw data is so that when we find 
a variable candidate we can go back and mark it on a raw frame and look for 
problems from nearby stars.  I expect that after we do this for a while we 
will get quite good at spotting problems.

I can imagine putting up big lists like DS23 and having several people look 
at each star in depth.  We only need to get a small percentage of the group 
active in doing this to keep up with the data taking of the Mark IVs.   I 
would put up the list and ask people to initial stars that they have 
verified.  I would keep updating the list to encourage others to look at 
stars given the least attention.

So tass fans, there is going to be lots to do in the future.  It should be fun.

Tom Droege

At 03:59 PM 6/2/02 -0700, you wrote:
>John wrote that he uses the Aladin interface for checking
>stars; this is a good idea for *all* observers, as you can
>look at deeper, good-seeing plate material when picking
>isolated comp stars.
>   However, the problem is that TASS, as well as just about
>every other automated survey, will find thousands of variables.
>You cannot manually look at each and every one.  Checking the first few
>is a good idea, but you need a software method of removing
>false positives.  The WS index is one such test.  For FASTT, we also
>chose the astrometric position, throwing out those stars whose
>variation corresponded to a simultaneous centroid error or fwhm error.
>Sure, you end up throwing away a few true variables, but there are plenty
>to go around!
>Arne