Re: Atypical variable stars...

[Thomas Droege <tdroege2@earthlink.net>]

Hmmm!  I did not seem to get Robert Bradbury's note.  I wonder why.  I did
see him sign up for the list.

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

I am running 3 dual systems every clear night.  On average about 1M
measurement pairs.  We are adding two more pairs which should be ready in
the fall.  Looks like Rob Creager is starting to get production data.  My
data is loaded to the data base monthly, though at the moment I am a couple
of months behind as I straighten out a date problem.  I should be up to
date soon.

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

Probably.  The systems seem to have a maintenance problem, even for me.  I
am slowly beating the problems down.  I still have lots more parts, but
probably not the energy to turn them into working systems.  Possibly
someone who has a system and is not operating might be willing to turn it
over to someone interested.  I would say that such a person should have an
electronics background and should be really motivated.   It takes a lot of
time to run a survey, and you don't get much credit.  You have to really
want to do it.  

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

There are no "detailed plans".  There is documentation.  Complete
schematics, etc..  Optics design, etc.. all on the home page if you look. 
But as Michael says, it is spread out.  

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

Let's see, I have spend around $500,000 and am near to completion of 9
systems.  This puts it at $55,000 per system.  However only 4 seem to be
operating at the moment, so that puts it at 125,000 a system.  On the other
hand, dividing the total cost by the measurements in the data base, we come
to about one cent per measurement pair.  When I first started the project,
I did the design optimization (as a good engineer should) based on cost per
measurement.   I recall I was shooting in the 1 cent range, so I think it
has been pretty successful.  Do the same computation for the satellite
programs and you will see that tass is *very* successful.

On the other hand, if you go buy a cheap commercial system, a small camera
and a short focal length automated camera and take advantage of the
software work that Michael Richmond has done, you could be adding to the
tass data base in a few months.  Let's say a $2000 camera and a $2500
telescope with a filter changer and $500 worth of computer.  Such a system
might have 1/40 of the throughput of a tass system.  Roughly 10,000
measurement pairs a night.  If 100 of you did this, then they would match
the tass output.  It would be very useful for this to become a long term
"thing to do", since there are many things that will only be discovered by
long term observation and I will not (at 74) last long enought to do the
measurements.  

Note the costs above.  It is more expensive to take measurements with a
small system.  That is why I bought the largest CCD I could afford and why
the systems were designed as they were.  Best to move the system to a good
location.  But 365 day operation in a bad location beats 2 week vacation
operation in a good location.  So you have to live at the good location or
solve the automation for remote operation.  Pojmanski seems to have done
this and operated his systems for ASAS in Chile from Poland.

Michael writes:

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

You bet, there is lots of data to be analyzed.  When the weather gets bad,
I plan to work on the data to find all those long period stars for which we
will have two years of data.  Little work has bee done on this, but if you
try it is like shooting fish in a barrel.  It is easy to find hundreds of
new long period candidates. 

> > 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?
>

The tass data is available to anyone who wants to give it a home.  From
time to time I try to negotiate with someone to take it off our hands.  I
have 2000 CDs of primary images I would like to find a home for since they
are sometimes useful to determine why something happened.  For example,
some time back sorting through the data base I found several stars where
the V and I measurements both brightened a lot on an image pair.  In one
case this was caused by an asteroid happening to pass on top the star, in
another a faint satellite track was enough to brighten the star without
being eliminated by the software.  

Note that *you* are the "people involved with TASS".  Anyone here can do
anything.  OK, there are implied rules of good manners.  Credit should be
given for work of others.  But the data is public.  If you see something
that can be done with it you are allowed to do it.  In some cases some
negotiation will be required.  For example, if you find a library or
archive that wants to take my 2000 CDs of images, you will have to
negotiate with me to give them up.  But other than things like the
commitment of other people's stuff, you can do what is possible to do.

Tom Droege


> [Original Message]
> From: Stupendous Man <richmond@stupendous.cis.rit.edu>
> To: <tass@listserv.wwa.com>
> Cc: <mwrsps@rit.edu>
> Date: 8/24/2004 10:21:25 AM
> Subject: Re: Atypical variable stars...