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| GGGGGGG HH HH RRRRR SSS |
STScI | GG HH HH RR R SS | STAN - GHRS
Analysis | GG GGG HHHHHH RRRRR SS | Number 1
News | GG GG HH HH RR R SS | October 1994
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* * * W E L C O M E * * *
You just received the first issue of STAN, STScI's Analysis Newsletter. This
publication will arrive in your electronic mailbox monthly. It will contain
brief articles of interest to all users of HST data.
This first mailing of STAN-GHRS is being sent to Principal Investigators. Please
let us know if there are other people on your team that you would like to
add to our distribution list (e.g., Co-I's, postdocs, graduate students, etc.).
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CONTENTS:
- GHRS NEWS
+ Error in the Doppler Compensation for Moving Targets
+ Calibration Product Review for Cycle 4 (ISR #67)
+ GHRS Stability.
- GETTING THE LATEST SCHEDULING INFORMATION.
- Appendix A: GHRS CONTACTS
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GHRS NEWS
---------
by David Soderblom (soderblom@stsci.edu)
GHRS Instrument Scientist
Doppler Compensation for Moving Targets
---------------------------------------
As you probably know, the GHRS automatically corrects for the motion of
the HST spacecraft while spectra are being obtained. Since the peak-to-peak
motion of HST is about 15 km/s, this correction is mainly relevant for echelle
observations of targets near the orbital plane.
An error in this compensation was recently discovered. Observations of
moving targets have not been compensated properly because the true position of
the object was not taken into account. Observations made for the comet
Shoemaker-Levy 9 campaign (mid-July) and thereafter should not have a problem,
but earlier observations might. We believe we have identified those observations
for which this problem may be pertinent and we have notified the appropriate PIs
We have now tested an algorithm that computes the Doppler compensation that
should have been applied as well as that which was, so that observers and
archival researchers can correct their data. If you have questions on this
matter, please contact us (a complete list of contacts is at the end of the
newsletter).
Calibration product review for Cycle 4 (GHRS ISR #67)
------------------------------------------------
We have just written GHRS Instrument Science Report 67, "Calibration
Product Review for the GHRS in Early Cycle 4." This ISR lists the header
keywords used by the GHRS pipeline calibration software (calhrs) in reducing
GHRS observations, provides a summary of the tables accessed by these steps
and the history of associated files. Most users of GHRS observations will
probably want to examine this ISR. It should be available on the Space
Telescope Electronic Information System, STEIS by the time you read this, or at
least by November 1. This PostScript file is called "reference_files_9407.ps".
You can retrieve it via anonymous ftp to stsci.edu from the
/instrument_news/ghrs/postscript directory or using Mosaic and looking
in gopher://stsci.edu/11/instrument_news/ghrs/postscript. Please see the next
article if you have never used Mosaic. If you wish a paper copy, please send a
request to a GHRS Instrument Scientist or etkins@stsci.edu.
GHRS Stability.
--------------
We regularly monitor the performance of the GHRS, and we have seen no
changes of significance since the Servicing Mission Orbital Verification,
either in sensitivity or wavelength. We are working on improving the default
wavelength scale supplied by calhrs, and will report on that in a future issue.
================================================================================
GETTING THE LATEST SCHEDULING INFORMATION
-----------------------------------------
by Mark Johnston (johnston@stsci.edu)
PRESTO Project Lead
You can check the implementation and scheduling status of your observations
by using the PRESTO (Project to Re-Engineer Space Telescope Observing)
public page available via the World-Wide Web. This is most easily accessed
through the Mosaic client program (as described below), although other WWW
browsers are also available. The PRESTO page provides a wealth of information
about the status of the HST observing program, including the weekly timelines.
Once the developing long-range observing plan is in place, it will also be
available in this page.
1. Open MOSAIC. You may need to check with your system administrator
for site specific information. For example, at STScI the command is:
> Mosaic
2. Get into the PRESTO homepage.
An alternative way into PRESTO is through the Space Telescope
Electronic Information Service (STEIS)
(http://www.stsci.edu/top.html) by going to the OBSERVER
INFORMATION paragraph and clicking on PROGRAM STATUS.
NOTE: You might want to save this MOSAIC address by using the
"Navigate" pull down menu along the top, then the "Hotlist" button,
and the "Add Current". In the future you can just use the "Hotlist" to
open the PRESTO homepage.
3. Enter your program ID in the box and click on "Get Program Information".
4. Click on "Visit Status Information".
5. To save the information to a file click on the "Save as ..."
at the bottom of the page, name the file, and click on "OK".
6. Click on the "Close Window" to exit Mosaic.
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APPENDIX: GHRS contacts
-----------------------
Any questions about the scheduling of your observations should be addressed to
your PRESTO contact. If you do not know who this person is, PRESTO's Mosaic
page contains that information.
Any post-observation questions concerning calibration, data analysis, software,
etc. can be addressed to analysis@stsci.edu or by calling 410-338-1082.
These contacts will forward any detailed questions to the GHRS Instrument
Scientists, who are:
David Soderblom soderblom@stsci.edu 410-338-4543
Claus Leitherer leitherer@stsci.edu 410-338-4425
Steve Hulbert hulbert@stsci.edu 410-338-4911
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Comments about this newsletter, questions, requests for issues, addition or
deletions to the mailing list, etc. can be e-mailed to analysis@stsci.edu
================================================================================
The Space Telescope Science Institute is operated by the Association of
Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.
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