Re: Reprocessing Production

[Tass Mailing List <tass@mail.alembic.net>]

Date: Thu, 20 Sep 2007 18:33:35 +0200
From: Paul Bartholdi <Paul.Bartholdi@obs.unige.ch>
To: Tass Mailing List <tass@mail.alembic.net>,
     Thomas Droege <droege@slashmail.org>
Subject: Re: Reprocessing Production

Hello,

I wonder if the article by Alard and Lupton on optimal image substraction is
known in this group. It deals with photometry in crowded fields. If not, you
can take a copy on my site:
     http://obswww.unige.ch/~bartho/Allard_Lupton.ps.gz .
Best regards,     Paul

On 9/16/07, Tass Mailing List <tass@mail.alembic.net> wrote:
>
>
> Date: Sat, 15 Sep 2007 13:55:20 -0500
> From: Thomas F. Droege <droege@fastmail.fm>
> To: tass@tass-survey.org
> Subject: Reprocessing Production
>
> With a lot of help from Michael Richmond, I now have two computers
> reprocessing the data.  Looks like one computer can process 4 nights
> from one telescope a day.  13 nights from tom2 completed so far.  There
> are more than 100 and less than a thousand telescope nights to process.
> With luck I should finish in a month or so.  Only one disk unreadable
> so far.  Unfortunately, I have lost about 6 months of data when I
> could not make it up to the roof to write archive disks.  Sigh!
>
> We have learned a few things that I am particularly interested in
> studying.  When Michael was last here there was an interesting star.
> tass had 40 or so measurements that were just junk.  This is because the
> star was in a crowded field and suffered from variable contamination
> from nearby stars.  I want to look at less crowded fields and see if
> their statistics are different.  I have always looked an mixed samples.
>
> With 7.5 second pixels, there should be contamination.  It is a question
> of how one runs a survey.  With 100 mm optics, one has a difficult time
> covering the sky if the focal length is adjusted for little
> contamination.  I thought a lot about this in the very early days of
> tass and decided that I wanted to run the whole sky.  This means we lose
> the crowded areas.  Most observers use long focal lengths and look
> where there are lots of stars.  tass should have the rare advantage of
> looking at those parts of the sky that are seldom measured repeatedly.
> Possibly now that I understand this we can find some interesting things.
> We shall see.
>
> Tom Droege
>
> --
>   Thomas F. Droege
>   droege@fastmail.fm
>
>
>


-- 
****************************************************
Paul Bartholdi
Chemin de la Barillette 11
CH-1260 NYON
Suisse                      tel +41 22 361 0222
****************************************************