Re: fun with coadding images on Disk Set 19

[Tom Droege <tdroege@veriomail.com>]

OK, lets have a little more criticism of the present program.

Here is what I am trying to do every night:

1) Take a string of exposures covering about 4 x 30 degrees of sky.  This 
is done with overlapping exposures so that each star in the strip is 
measured two or three times.  This exposure string produces nightly 
measurements for the stars in the strip, and is the basis for dark and flat 
fields.  As this process is continued, data is accumulated for the 
observation nights for a month or so.  This takes about an hour.

2) Follow as many fields as possible for as long as possible for the 
remainder of the night.  I seem to be getting 2 to 3 fields these days on a 
good night.  I can follow a field for about 2 1/2 hours.  I just pick up 
whatever field is available when the previous field is completed.

This is my plan for TOM1, which can only see a limited area of the 
sky.  Probably about 0 to +10 Declination.  I will have to cut down a tree 
to get to zero or a little below.  I am presently looking at +4.  I plan to 
just sit on +4 for the next year or so with TOM1.  TOM2 and TOM3 will be 
more flexible, so will be better suited to do follow up programs.  They 
should also be able to follow up to 3 hours or more.

This will get 56 measurements on a star taken in two filters over 2 1/2 
hours on a single night.  It will get several measurements taken over a 
month or so.  It will get yearly measurements.

Tom Droege

>On Wed, 17 Oct 2001 11:36:04 -0700, aah@nofs.navy.mil wrote:
>
> >  So I suggested to Tom to sit on one field longer rather than
> >trying to scan an entire declination strip.  The advantage is that
> >you can study short time scale phenomena:  eclipsing systems,
> >delta Scuti stars, RR Lyrs, etc.  ROTSE may have discovered most
> >of the variables down to ~13th magnitude, but they don't have very
> >good light curves.  Don't worry about running the risk of
> >only measuring previously well studied objects; they are *not*
> >well studied.
>
>Amen to that. From an analysis point of view, the ROTSE curves are not
>of much use other than a rough classification to look for potentially
>(astrophysically) interesting systems.
>
>I see a couple of ways TASS can make unique contributions to the
>binaries field: (1) high-quality, multi-epoch data on systems that have
>variable light curves outside the eclipse/reflection/ellipsoidal
>variation (e.g. Algols with mass transfer events, W UMa systems doing
>who knows what) and (2) long-period, detached binaries (95+% of the
>light curve is flat so they're not easily found unless you look for
>them often over an extended period of time). The lack of #1 really
>hampers further progress on these types of systems. So, I agree with
>Arne, you'll make a much more valuable contribution by going for
>quality data on brighter stars. Plenty of people are merely trying to
>detect variables. What we need is an efficient system for getting
>high-quality follow-up data on large numbers of stars over long
>periods.
>
>Dirk
>