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Re: Da Plan
Sounds great, Tom. After being at a meeting or two where TASS came up
in casual conversation I think people are anxious for the engineering
run to end so that "da plan" stays consistent so the data stays
consistent. Engineers like to tweak things but something like a survey
is better off consistently imperfect than consistently in flux.
PS - this has been sitting unsent in my outbox for weeks. Thought I'd
send it just for the fun of it.
On Apr 18, 2005, at 7:38 PM, Tom Droege wrote:
> In Chicago we have Da Bulls, Da Bears and Da Tass. This is about Da
> Tass
> plan for the coming season.
>
> 1) Take tiles.
>
> We will take 4 x 4 degree tiles in the sky at the equator. Above the
> equator we will always take 4 degree in dec, but in ra they will
> enlarge
> as we go towards the pole. We will label the tiles with their integer
> ra,
> dec. We will produce .cal files representing an evenings run or part
> thereof as we have done in the past, we will also generate a set of
> tile
> files which will have file names including ra, dec and time. We note
> that
> the data looks much better, and really is better for the purpose of
> finding variables when presented this way.
>
> Tiles will overlap 0.2 degrees at the equator, at some declinations a
> lot
> more.
>
> 2) Take 200 second exposures.
>
> This should produce a few more stars than the previous runs. We shall
> see. Certainly the mag 12 stars will be measured slightly better. We
> think the real value of this survey will be from mag 10 to 12.
>
> 3) Scan -6 to the pole
>
> This requires 4 full time telescopes to get everything that croosses
> the
> meridian.
>
> 4) Report in near real time.
>
> We plan to take data in blocks of about 20 exposures. This is enough
> to
> make a good sky flat. We can thus produce a fresh flat with every
> block
> which might help to compensate for changing sky conditions. We expect
> to
> be able to put the .cal files on matt as they are reduced. An hour or
> so
> after the run ends.
>
> 5) One tom to track
>
> We will set one of the telescopes to track the sky. We can track for
> about 3 hours. This will produce a string of 36 or so exposures.
> Almost
> every set will have a new variable. At least that is my experience so
> far. We will put these as they are recuced on matt. Fair hunting.
>
> 6) Stop down the I telescopes.
>
> I have not settled this for sure yet. The I cameras see about twice
> the
> sky background as the V cameras. Stopping down to a 3 inch aperture
> makes
> the sky background about equal. I have tried this and the I focus is
> clearly better. Possibly I will cut masks at 3.5" and compromise.
> Get a
> little better focus and a reduced sky background. Still testing.
>
> Comments will be appreciated. It will be a month or two before this is
> cast in stone. Change is possible. With this set up, we find lots of
> variables in the range of mag 11-12. A lot of them will be new.
>
> tom1 is up and running. tom2 should be running in a week. We should
> have
> all 5 systems running by August when the good season starts here.
>
> Tom Droege
>
> This requires
>
>