From: downes@stsci.edu (Ron Downes)
Subject: Bright Object tool
To: leitherer@stsci.edu (Claus Leitherer), gak@stsci.edu (Jerry Kriss),
        cox@stsci.edu (Colin Cox), clampin@stsci.edu (Mark Clampin),
        keyes@stsci.edu (Tony Keyes), calzetti@stsci.edu (Daniela Calzetti),
        biretta@stsci.edu (John Biretta), mackenty@stsci.edu (John MacKenty),
        asbury@stsci.edu (Michael Asbury), krueger@stsci.edu (Tony Krueger)
Date: Wed, 24 May 2000 10:00:05 -0400 (EDT)
Cc: downes@stsci.edu (Ron Downes)
Content-Type: text/plain; charset=us-ascii
Content-Length: 4975

To:      Claus Leitherer/Jerry Kriss (STIS), Colin Cox/Mark Clampin (ACS), 
         Tony Keyes (COS), Daniela Calzetti (NICMOS), John Biretta (WFPC2), 
         John MacKenty (WFC3)
From:    Ron Downes
Subject: Bright Object tool in APT

As at least some of you are aware, as part of the Astronomer's
Proposal Tool (formerly SEA), there will be a Bright Object checking
tool.  While some of you have been working with Mike Asbury on a Cycle
10 tool (which will be limited in scope since most of APT is in in
place), I have been tasked to consider the final, full-up tool (likely
for Cycle 11).  This tool will be fully integrated with other APT
tools (such as the VTT and ETCs), and as such can be very powerful.  I
envision this tool being provided to the GOs as well as used
internally (the Cycle 10 tool will likely be strictly internal).  I
believe it appropriate for the tool to not just be a health-and-safety
check, but also to provide science warnings (e.g. a bright target in
the WFPC2 field that could cause bleeding).  Below you will find my
initial description of the final bright object tool for your
comments/criticisms/additions.  

Please provide any comments to me by ***JUNE 9*** (I would like to
hear from all groups, even if you have no suggestions).  If you would
like to meet with me (and Mike, who will be doing the programing) to
discuss this, please let me know.  For those SIs operational in Cycles
10/11, I would also like to receive the specific imformation alluded
to in step 4 below (I have included the information for STIS as a
sample).  Finally, I would appreciate it if you could provide a list
of any "science warnings" you would like included (the details of how
to implement them can come later if you do not want to provide those
at this time).

The information above will allow us to develop an initial strawman
schedule for development, and may also be useful for the Cycle 10
internal-use version.  I plan to fully involve the Instrument Groups
in the development of this tool.  If the Group Leads which to provide
contacts other than themselves (as STIS and ACS have done), please let
me know.
======================================================================
The Robust Bright Object Tool

The ultimate Robust Bright Object Tool (ROBOT) will be utilized by
both GOs and Instrument Scientists.  Information will be input from
the Phase II proposal (or its replacement), which will be used to
identify all the stars in the macro-aperture that are in the GSC2
catalog.  The color information of those stars will be converted to
spectral types, and each star will be run through the appropriate
Exposure Time Calculator to determine count rates.  The final product
will be a VTT display where all stars with health-and-safety concerns
are plotted in red, all stars with science concerns (e.g. bright
targets that could bleed) are plotted in yellow, and all stars that
are safe are plotted in green.  There should also be a printable
listing of the results for all targets.

It is important to note that this tool will only be useful for field
stars that are in the GSC2, and for the target if it is a normal star.
Extended targets will not appear in the GSC2, and will therefore need
to be checked by hand.  Variable targets, although in the GSC2, will
only have the magnitude at the time of the GSC plate, and may
therefore not have the "correct" magnitude for the time of
observation.  While most variables have small amplitudes, some objects
(e.g. cataclysmic variables and symbiotics) have large amplitudes,
which could pose problems (either as field objects, or as the prime
target). To handle this case, we may wish to ingest the catalogs for
CVs and symbiotics so these objects can be properly flagged.

The ROBOT should work as follows:

1) information from the Phase II proposal (or its replacement) are
ingested; the specific information needed is the target position and
science aperture.

2) the GSC2 is searched for all objects (even those flagged as not
usable as guide stars) within the macro-aperture.  All area targets
are ignored.

3) the color information is converted to a V magnitude and spectral
type via a lookup table.

4) information from the Phase II proposal (or its replacement) are
ingested; the specific information needed is the exposure information
(spectral element, aperture, and central wavelength, for STIS;
information for WFPC2, NICMOS, and ACS will come from those teams).

5) the information in step 4 is passed to the appropriate Exposure
Time Calculator for each GSC2 object.

6) the ETCs return the countrates for all targets, which are compared
(via a lookup table) to the health-and-safety limits, and to science
concern limits.

7) the target field is re-displayed on the VTT, with the following
codes for the stars:

red - target is a health-and-safety concern
yellow - target is a science concern
green - target is safe

A printable version of the ETC output should also be given.


