S T A N / W F P C 2 - Number 31, April 1998

CONTENTS:

• WFPC2 NEWS:
• WFPC2 Cycle 6 Calibration Closure Report - Instrument Science Report WFPC2 98-01
• Time-Dependence of the Charge Transfer Efficiency Confirmed
• New Special Requirements for Proposal Processing
• DATA ANALYST POSITION AVAILABLE AT STScI
• RECENT PREPRINTS
• APPENDIX: WFPC2 CONTACTS

WFPC2 Cycle 6 Calibration Closure Report - Instrument Science Report WFPC2 98-01:

by S. Baggett, S. Casertano, and the WFPC2 Group

This report describes in detail the WFPC2 observations used to maintain and improve the quality of WFPC2 calibrations during Cycle 6, and the status of their analysis as of February 1998. Also included are summaries for three Cycle 5 proposals (Flat Field Check, UV Throughput, and Polarization and Ramps) which have been completed since the writing of the Cycle 5 Closure Report.

Time-Dependence of the Charge Transfer Efficiency Confirmed:

by B. Whitmore and I. Heyer

In December, the WFPC2 Group reported tentative evidence that the Charge Transfer Efficiency (CTE) loss for very faint stars observed with the WFPC2 had increased from about 4% in April 1994 to about 20% in June 1997. The major effect of CTE loss is that stars at the top of the chip appear fainter than stars at the bottom of the chip. The change with time is smaller for brighter stars, and for the brightest stars there is no significant change with time. Based on these results new monitoring observations were inserted into the WFPC2 calibration plan to monitor the effect every 6 months. Analysis of the first set of observations (taken March 23, 1998) indicate that the trends have continued, with a CTE loss of roughly 26% for the faintest stars. In general, typical WFPC2 exposures are much longer than these short calibration images, resulting in higher background which significantly reduces the CTE loss and minimizes the CTE problem for most science observations.

A more complete analysis will be available in the near future.

New Special Requirements for Proposal Processing:

by A. Storrs and D. Golombek

These special requirement keywords will be added, as needed, by your Program Coordinator after discussing with you the pertinent implementation issues that forced its inclusion. Please contact your PC with any questions you might have.

The special requirement keywords:

VISIBILITY INTERVAL 
NEW OBSET
NEW ALIGNMENT
SAME OBSET 
SAME ALIGNMENT 
SAME ALIGNMENT  DONT SPLIT
SAME GUIDE STARS 
OBSET ID 
ACQ PCS MODE GYRO
ACQ PCS MODE COARSE
ACQ PCS MODE FINE
GS ACQ SCENARIO 
   (where  can be SINGLE, PAIR, GYRO, or something else)

Data Analyst Position Available at STScI:

The Space Telescope Science Institute currently has openings for Data Analysts. Data Analysts in the Science Support Division help General Observers and Archive Researchers analyze HST data, work with Instrument Scientists in calibrating the HST instruments, and work with STScI staff on grant-supported research projects. These research projects span a range of size scales from comets and planets to the large scale structure of the universe and a range of wavelengths from radio to X-ray astronomy.

Applicants should possess a B.S. degree (M.S. degree a plus) in astronomy or physics, or equivalent; experience with astronomical research; familiarity with scientific computing; expertise in data analysis; knowledge of IRAF, IDL or other software packages for astronomical data analysis; and programming ability. Additional mathematical, statistical, and computer skills are desirable. Candidates should have the ability to work with a minimum of direction, enjoy research, and possess skills to develop excellent working relationships. Candidates should send a cover letter with current curriculum vitae and the names of three references to:

Human Resources Manager
Space Telescope Science Institute
3700 San Martin Dr.
Baltimore, MD 21218

Women and minorities are strongly urged to apply. AAE/EOE.

RECENT PREPRINTS:

We draw your attention to these papers, based on WF/PC and WFPC2 data, that will appear in the next few months. This list includes all preprints received by the STScI Library not yet published in the journals. Please remember to include our Library in your preprint distribution list.

BOBROWSKY, M.; SAHU, K.C.; PARTHASARATHY, M.; GARCIA-LARIO,
P.  "Birth and Early Evolution of a Planetary Nebula"
Nature accepted

HUGHES, S.M.G.; HAN, M.; HOESSEL, J.; FREEDMAN, W.L.;
KENNICUTT, R.C. JR.; MOULD, J.R.; SAHA, A.; STETSON, P.B.;
MADORE, B.F.; SILBERMANN, N.A.; HARDING, P.; FERRARESE, L.;
FORD, H.; GIBSON, B.K.; GRAHAM, J.A.; HILL, R.; HUCHRA, J.;
ILLINGWORTH, G.D.; PHELPS, R.; SAKAI, S.  "The Hubble Space
Telescope Extragalactic Distance Scale Key Project. X. The
Cepheid Distance to NGC 7331"  ApJ 7-1-98

CAROLLO, C.M.; STIAVELLI, M.  "Spiral Galaxies with WFPC2.
III. Nuclear Cusps Slopes"  AJ accepted

CAROLLO, C.M.; STIAVELLI, M.; MACK, J.  "Spiral Galaxies
with WFPC2. II. The Nuclear Properties of 40 Objects"  AJ
accepted

GOLIMOWSKI, D.A.; SCHROEDER, D.J.  "WFPC2 Observations of
Proxima Centauri: No Evidence of the Possible Substellar
Companion"  AJ 7-98

GOULD, A.; FLYNN, C.; BAHCALL, J.N.  "The Spheroid
Luminosity and Mass Functions from Hubble Space Telescope
Star Counts"  ApJ 8-20-98

MALKAN, M.A.; GORJIAN, V.; TAM, R.  "A Hubble Space
Telescope Imaging Survey of Nearby Active Galactic Nuclei"
ApJS 7-98

ROMANIELLO, M.; PANAGIA, N.; SCUDERI, S.; SINS
COLLABORATION  "HST Study of the Stellar Populations Around
SN 1987A"  Magellanic Clouds and Other Dwarf Gal.

APPENDIX: WFPC2 Contacts:

Any questions about the scheduling of your observations should be addressed to your Program Coordinator. Post-Observation questions can be addressed to your Contact Scientist. If you do not know who these persons are, you can find the information on the WWW at www.stsci.edu/public/propinfo.html.

Analysis, STSDAS or any other questions can also be addressed to help@stsci.edu.

To subscribe or unsubscribe send a message to listserv@stsci.edu with the Subject: line blank and the following in the body:

 
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