Re: Question from Roy Tucker, forwarded to TASS

[Tom Droege <droege@fnal.gov>]

I correspond with Roy from time to time. 

I think Roy is a lot more like me than the rest of you.  Many of you 
given the tass software and a bunch of Roy's images, could write a 
script to process them and search out moving objects.  For me, this 
would be a daunting task. 

This is why I work with tass.  Together we can do things which any 
one of us could not attempt.  

We may operate the Mark IVs in just this mode.  We will have the 
advantage that with a dual we will be able to generate a cleaner 
image on the first exposure, so that the second exposure will really
show up moving stuff.  

I assume that all our software is available to Roy.  I suspect that
he is somewhat like me, and really not up to the software work involved
in using the available stuff.  Perhaps Mike would like to add a "moving
object finder" to his commercial package. Sigh! I would give him a plug
if I could remember the name - "Image Scientist" comes to mind but I 
may have it wrong.  I could remember "Deep Sky".  A feature like this 
might distinguish it from other packages.

Certainly we will want to eventually do moving objects.  The real reason
for doing variable stars is that it is easier.  By doing this first we 
will all gain experience, and the satisfaction of some success.  If we
went for the moving objects first, we might give up before we ever 
acomplished anything. 

Tom Droege   

At 02:12 PM 5/26/98 -0700, you wrote:
>I got some e-mail from Roy Tucker last week.  Many of you may 
>know him.  Rather then forward I'll summarize it.
>
>It seems he has a very tass-like project he has been running
>my himself for quite some time.  It it's present form he
>operates a 1K x 1K CCD in drift scan mode.  Having only one
>camera, he collects one hour of data then "rewinds" the system
>and scans the same part of the sky again.  He does two "rewinds"
>to collect data like a TASS triplet, one hour apart.  He is also
>looking at the same part of the sky as TASS for the same reason.
>Drift scan simply works best at the equator.  One major difference
>is that he is using a C14, not a 135 mm camera lens.  His images
>are about 4 or 5 magnitude deeper than TASS Mk III images.  They
>are still fairly wide as his CCD has bigger and more pixels than 
>the KAF400.  I have seen some samples of his data and by eye they
>look just like TASS images when viewed by ximtool.  I see similar
>artifacts.
>
>Roy is interested in N.E. Asteroids and has in fact discovered a 
>couple of them with his system.  He "processes" his data by eye
>by blinking the images.
>
>His question (paraphrased) to me and to the TASS list in general 
>is this:  
>  "Blinking is very time consuming with many images 
>   per night it takes a lot of time and energy.  Is there 
>   any software used by TASS that could automate the search?"
>
>I looked at a set on three images he took and used to discover
>a N.E. Asteroid so I knew beforehand that there was something
>of interest.  I tried blinking them.  What a lot of work!  Even
>knowing that there is an asteroid there, it takes a lot of effort
>and skill to pick it out.  Maybe one learns over time but I 
>never would have found anything on these images.  He takes about 
>60 per night and he lives in a place where there are many clear 
>nights.  So I can see that automation could help.
>
>If he were to run an object extractor on his images.  He would
>have starlists that look just like TASS starlists.  Asteroid search
>software would then work on either data source Tucker's or TASS's.
>
>It has been said many times now that TASS (even Mk IV) is unlikely
>to discover any new asteroids.  Maybe true, but it may still see
>many known asteroids.  Could we measure rotation periods photometrically?
>Has this too "been done" and every known asteroid has been measured?
>How about if a rotation rate changed? _That_ would be a discovery.
>I assume such indirect observation of a collision would be worth
>writing a paper about.  Does it happen often enough to be observed?
>Has anyone tried looking? 
>
>I had thought that TASS may see some nova.  Most may be to dim but
>Mk IV may catch a few.
>
>Our current data processing system will ignore these evens.  I think
>we need a "discovery pipeline".  It could run along side the "stellar
>photometry pipeline" now taking shape.  If TASS wants to do this and
>Roy wants to automate his data reduction it may make sense to work
>together or at the least to keep software generalized enough that it
>can be shared between the two projects.
>
>For those who want to try their eye at blinking images.  His set of
>three FITS images with which he discovered a N. E. Asteroid is at
>his home page (see below)   He will be at the San Diego
>AAS meeting and has offered to give me a larger sample of data on
>CD-ROM.  We can talk about how TASS and his drift scan project may or
>may not fit together possibly Sunday or Saturday afternoon. Perhaps
>some others would like to meet with him also.
>
>Here is a quote:
>> Image scale is
>> about 2.56 arcseconds per pixel. The data consists of sets of three scans
>> of twenty 512x564 images for a total of about 60 MBytes. As a sample, you
>> can download the discovery images of 1998 FG2 from my web site at
>> "http://www.azstarnet.com/~gpobs/gpobs.htm". It was a nice, bright 18th
>> magnitude at the time of discovery.
>
>-- 
>--Chris Albertson
>
>  chris@topdog.logicon.com                Voice:  626-351-0089  X127
>  Logicon RDA, Pasadena California          Fax:  626-351-0699
>
>