Re: Atypical variable stars...

[Stupendous Man <richmond@stupendous.cis.rit.edu>]

  Robert J. Bradbury asks some questions about TASS:

> 1) How active is the project at this point in time? 

  Two sites (or more? correct me if I'm wrong!) are gathering
data each clear night.  One site's measurements are freely available
in an on-line database; the other's will be eventually.

> 2) Have all of the TASS cameras been built and deployed

  I would say, "yes, for the moment", but Tom might want to 
correct me.

> 3) Are there actual detailed plans available that document
> how to build the optics and CCD camera(s) involved in TASS?

  I don't know of any single document which has all the information
on the design of the telescopes and detectors.  You can find a 
great deal of information in a number of Technical Notes; browse
the list at

        http://stupendous.rit.edu/tass/technotes/index.html

> 4) To become involved in TASS how much cash layout should
> one anticipate? 

  If you want to build your own hardware which is identical to the
Mark IV, I'd guess many tens of thousands of dollars.  It is possible
to put together simpler wide-field camera systems using commercial 
units for, oh, anywhere from a few thousand to fifteen thousand
dollars, depending on your preferences.

  If you want to scan through the database, on the other hand,
using measurements gathered by others, then it costs nothing.

> 5) Are people involved with TASS working towards integrating
> the TASS data into the databases being developed by NASA/CALTECH/JPL(?)
> that would integrate data from multiple survey efforts?

  As far as I know, no.  However, in the past, we've placed our
measurements in the SIMBAD archive, and it's certainly possible 
that we'll do something similar in the future.  There's nothing
to prevent a person who wants to integrate our data into a giant
collection from doing it himself, either.

> I would like to ask the question of whether or not the
> TASS data reduction processes are capable of detecting
> what I would call a "long term variable star".
> 
> In the cases I am thinking of "long term" might be anything
> from days to years.  ... one has an observed star that
> "fades to black" over some period.  It would differ from
> classical supernovas in that there would not be any increase
> in brightness associated with a supernova event at the
> beginning.

  The Mark IV database would be a good place to look for such
events; one of the best places, in fact, as long as you can live
with the relatively bright magnitude limit, because it covers a 
_lot_ of stars with frequent measurements over a time period of ...
let's see ... roughly two years, at this point?  

>  It may be the case that
>  current screens for variable stars in the TASS data
>  would miss the types of objects that I am interested in

  No, there are no reasons such objects would be missing
from the TASS database, as long as they are bright enough to
be detected in both the V and I passbands.  But you would
have to go through the database to find them for yourself.

                                       Michael Richmond