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Stsci/Newsletters/august90

August 1990 Newsletter

HIGHLIGHTS OF THIS ISSUE:
 Successful Launch and Deployment of HST
    Institute Responds to Flaw in HST Optics
    Scientific Instruments Working Well
       First Hubble Fellows Named
        Cycle 2 Deadline No Earlier Than Feb. 1991

Contents
1. A Message From the Director
2. Project Status
3. HST Strategy Panel
4. Update on HST's Imaging Performance
5. The Science Assessment Program
6. Plans for Reassessing Accepted Observing Programs
7. Reconstruction of HST Images
8. XCAL
9. Instrument News
        9.1 WF/PC
    9.2 FOC
    9.3 FOS
    9.4 GHRS
    9.5 HSP
    9.6 FGS
10. STSDAS News
11. A Report from the Educational Front
12. Hubble Fellowship Program
13. Institute News
    13.1 Sabbatical Visitors
    13.2 ESA Fellowships
    13.3 The May 1990 Workshop
    13.4 STScI Preprints
    13.5 Staff News
    13.6 STScI Electronic Information Service
    13.7 How to Contact STScI
    13.8 Newsletter Notes


1.    A MESSAGE FROM THE DIRECTOR

The title of this Newsletter could be Triumph and Tragedy. After
years of waiting, the Hubble Space Telescope is in orbit. The
excitement and emotions we all felt as the Shuttle backed away from
HST and left it to begin its operations are hard to convey. The first
few weeks, in which increasingly complex operations were attempted and
successfully carried out, were almost devoid of substantial technical
problems. Finally, as we tried to proceed through telescope focusing,
the seriousness of the telescope's spherical aberration became evident.
  From premature elation, the public and media swung to considering HST
as lost. The truth is not so bleak. Fixes that will restore HST's
resolving power, at least on an instrument-by-instrument basis, are
being studied. They could be implemented as early as 1993, when a new
version of the WF/PC could be substituted in orbit with the
appropriate correcting optics. In the meantime we will attempt to
maximize scientific return with the existing capabilities. A
substantial fraction (~50%) of the planned program can be carried out
either without modification or at the cost of increased exposure times.
It is clear, however, that many of the fundamental investigations
planned with HST will have to be deferred for several years until the
optics corrections are made.
  The human cost of this technical failure is harder to assess. Young
scientists who had based their careers on the early use of the HST
will have spent ten years of their lives waiting. Literally hundreds
of scientists had initiated research groups and activities in
preparation for the flood of new HST results. The cost and waste in
scientific manpower is itself a severe blow to space astronomy.
In my opinion, the astronomical community should respond to this
tragedy by committing itself to work very hard to prevent it from
recurring in this or other space- astronomy programs. The community
must assume greater responsibility in the conduct and execution of
these programs to insure their success. The STScI staff is dedicated
to this goal.
 - Riccardo Giacconi

2.    PROJECT STATUS
HST was carried into orbit aboard Discovery on April 24, and
successfully deployed on the following day. After the deployment, the
Orbital Verification (OV) phase of the mission began. OV is a
carefully planned sequence of activities designed to check out the
basic performance of the HST systems.
  The early stages of OV concentrated on the verification and
calibration of the support systems, including power, thermal, and
attitude control. Due to several well-publicized problems, this phase
of the mission proved to be somewhat more difficult than anticipated
and took longer than expected. However, all of the basic spacecraft
systems are working well. The InstituteUs capabilities to carry out
its planning and scheduling responsibilities successfully, as well as
real-time operations and data processing, have also been demonstrated.
In fact, STScI has been able to respond to continuously changing
observing requirements during this initial verification period.
It has been discovered that a thermal excitation of the solar-panel
assemblies occurs when the spacecraft passes into or out of direct
sunlight, resulting in significant pointing jitter. Specialists on the
pointing control system expect to remedy this problem with a
modification to the onboard control software. It is expected that this
modified software will be in use in September, bringing the pointing
performance within acceptable tolerances.
  The OV activities then shifted to the checkout and focusing of the
telescope's optical system and an initial checkout of the five
Scientific Instruments (SIs). As described elsewhere in this issue, a
serious problem with the optics was soon revealed. It appears, based
on operations to date, that all of the SIs are operating properly,
although relatively little data have as yet been obtained on
astronomical targets with SIs other than the WF/PC and FOC. It also
appears that the Fine Guidance Sensors are operating properly and,
when the calibrations are complete, that they will be fully able to
conduct both spacecraft guidance and astrometry measurements. More
details on the status of the SIs are given below.
  On July 16, Marshall Space Flight Center passed responsibility for
direction of HST operations to Goddard Space Flight Center. This was a
planned transition between completion of the first phase of OV and
commencement of the second phase. OV1 was designed to check out and
calibrate the basic spacecraft systems, while OV2 concentrates on the
commissioning of the SIs. When OV2 is finished, the Science
Verification (SV) period will begin; this is expected in September. SV
activities will accomplish the initial scientific characterization and
calibration of the instruments for the conduct of the observing
programs.
 - R. W. Milkey

3.    HST STRATEGY PANEL
Riccardo Giacconi has formed an HST Strategy Panel to identify and
assess strategies for recovering the HST capabilities currently
degraded by spherical aberration. The panel consists of a small number
of astronomers and engineers from STScI and from the national and
international astronomical communities. The panel reports to Dr.
Giacconi and has been chartered to discuss a broad range of ideas for
restoring the telescope's full scientific capability, and to debate
them with respect to their technical and scientific merits. If
necessary, the panel can call on STScI staff for technical support.
The panel's conclusions and recommendations will be presented to Dr.
Giacconi in a final report within two months. The HST Strategy Panel
will be co-chaired by the undersigned.
 - Holland Ford and Robert Brown

4.    UPDATE ON HST'S IMAGING PERFORMANCE
A special mailing was sent to Newsletter subscribers in mid-July; it
described HST's optical problems and provided initial assessments of
the impact on the capabilities of the Scientific Instruments. The
purpose of this article is to provide additional information that has
become available since that material was issued.
The Faint Object Camera (FOC) has now taken its first image in the
ultraviolet. A reproduction is given above. Defining the total flux as
that contained in a 4" square box, we find that 0.9% of the total is
contained in the central pixel, and 8% within a radius of 0".1. The
observed total counts agree (within a factor of about 2) with
pre-launch predictions, showing that the UV throughput of the
telescope is close to nominal. On the other hand, the central pixel
contains some 50 times less light than pre-launch predictions, because
of the spherical aberration.
     The next figure (page 4) shows predicted encircled-energy curves
(calculated in a ray-trace approximation) for five different settings
of the telescope focus. Rays from near the center of the mirror
converge at the paraxial focus. Moving away from the secondary mirror,
one next encounters a point where the maximum encircled energy within
a 0".1 radius occurs. At 2500 , this point lies 9 mm from the
paraxial focus, and at that setting about 12% of the light is
encircled within the 0".1 radius. In the visible, this point occurs a
few mm further from the paraxial focus, and about 15 percent of the
light is encircled (both observationally and in the predictions). The
remaining curves in the figure correspond to the diffraction focus (at
which the RMS wavefront error is a minimum), the circle of least
confusion, and the marginal focus (at which rays from the outer edge
of the mirror converge). These foci lie at distances of 24 mm, 32 mm,
and 43 mm behind the paraxial focus, respectively. The focus position
that will be adopted for scientific observations has not been decided
at this point, but will be close to the setting that maximizes the
encircled energy within a 0".1 radius.
      Presently, effort is being concentrated on determining the exact
nature of the aberrations. When this is completed, in combination with
the results of the Allen Commission, we should be in a position to
specify the changes to the spacecraft optics necessary to correct the
problem. A further result of that process will be a final
determination of the best focal position. A series of fine steps with
the secondary mirror, accompanied by images in both the FOC and WF/PC,
and eventually a corresponding experiment with the spectrographs, will
provide important inputs to that determination.
      The figure below shows the encircled energy predicted for various
sized apertures as a function of focal setting, at 5000 . These
results agree within about 10% with the existing measured data in the
cameras. The predicted performance is qualitatively similar at other
wavelengths, with generally lower encircled energy results expected in
the UV (see the May 1990 OTA Handbook, page 33), because of mirror
microroughness scattering.
 -  Chris Burrows

5.    THE SCIENCE ASSESSMENT PROGRAM
The spherical-aberration problem of the HST has a profound influence
on the scientific capabilities of the observatory. The effects on the
scientific programs of both Guaranteed Time Observers (GTOs) and
General Observers (GOs) must be assessed and quantified as soon as
possible to allow the impact on each program to be established
properly and to enable the orderly implementation of the Cycle 1 (and
Cycle 0) observing programs. (See also the following article.)
Two complementary approaches are being followed to tackle this
problem. The first is to carry out detailed simulations of the HST
point-spread function (PSF) and to use them together with software
packages that simulate the instrument characteristics, in order to
derive integrated PSFs through the cameras and spectrographs. These in
turn can be used by each GO or GTO to convolve with the astronomical
object to be studied, in order to determine exposure time or
signal-to-noise requirements. These simulations are a very important
tool in the work that lies ahead for all of us.
The second approach is to obtain a representative, but limited, set of
real observational data as early as possible.
   At the June meeting of the Science Working Group and Users' Committee
at which the spherical-aberration problem was initially discussed, it was
agreed that a small team would be established to define and implement an
early-observation program to assess the scientific capabilities of the
Scientific Instruments (SIs) as they currently exist. Team members are
D. Ebbetts (GHRS), S. Faber (WF/PC), H. Ford (FOS), E. Nelan (AST),
and R. White (HSP), with the undersigned as chair.
    This Science Assessment Team (SAT) met on four occasions over a
three-week period. We discussed the need to define the characteristics
of the best focus for each SI.  In principle it is not obvious that
the best focus position for the cameras is the same as that for the
spectrographs or HSP. After some discussion we agreed that, for
consistency, and as a working hypothesis, we would all choose the
focus that provided the maximum spatial-resolution information, namely
the focus that achieved the strongest central peak in the energy
distribution, even at the expense of having broader wings. We also
recommended that a series of measurements be obtained with the WF/PC
and FOC in a fine grid around the best-focus position to
characterize fully this focus and assist in the final determination of
the best-focus position. These observations will be carried out in the
ultraviolet and visible with the FOC in the f/288 and f/96 modes. The
WF/PC will be used in its PC mode with a visible filter.
     The SAT then discussed and agreed on a series of short observing
programs to be carried out with each SI. The list of objects includes
point-like sources and extended targets in both isolated and crowded
fields, and covering a range of brightnesses. All of these programs
are part of existing GTO programs and therefore do not infringe on any
observing programs. The current plans are to begin the observations
with the cameras around the middle of August. These observations will
last for about one week. This will be followed by the implementation
of the improvements to the Pointing Control System software (see
above), which should remove the spacecraft jitter induced during the
day/night transitions. After some necessary Science Verification
activities, required for example to determine accurately the positions
of the entrance apertures of the spectrographs, the SAT program of the
spectrographs and HSP will be carried out.
  The data obtained from this program will be made available immediately
to the HST Project, to the Investigation Definition Teams (IDTs), and
to STScI to assist in the determination of the SI characteristics. A
summary of this information will be sent to the GOs and GTOs to aid in
their assessments of the impact of the spherical aberration on their
particular observing programs. After evaluation by the IDTs and the
STScI, the data will be made available to all GOs who request it.
Sample non-proprietary data will also be made available in the STScI
Electronic Information Service, under the RObserver/DataS
sub-directory.
 - F. Duccio Macchetto

6.     PLANS FOR REASSESSING ACCEPTED OBSERVING PROGRAMS
The recent determination that HST's imaging capabilities do not meet
the design specifications makes it necessary to reassess the pool of
accepted proposals for Cycles 0 and 1 in terms of the ability to
attain their scientific goals, and to develop a plan for allowing the
necessary modifications to be made by the observers. Although a final
policy decision has not yet been reached, the strategy that is
envisaged is to break the GTO and GO proposal pools into five
categories: (1) no changes required; (2) minor changes required; (3)
major changes required; (4) program to be deferred; (5) program to be
withdrawn. This categorization will allow STScI to continue the
scheduling process for programs that have no changes or only minor
changes, while allowing the major changes to be made as late as
possible, when the most current information about the performance of
HST and the instruments will be available.
  The GTOs have already been asked to sort their Cycle 0 proposals into
these five categories. They will make the necessary minor
modifications during September, and the major changes during October.
The procedures for making changes to Cycle 1 GTO proposals will be
similar, but the timeline will be roughly the same as the timeline
described below for the GOs.
  The GOs will receive detailed instructions concerning their programs
in late August. The sorting step will be performed by a combination of
evaluations by the GOs, the Telescope Allocation Committee (TAC), and
the STScI instrument scientists. The GOs will begin making their
assessments of the impact of the spherical aberration on their
programs when they receive the August mailing. This mailing will
include some preliminary information about what the effects are likely
to be, and instructions on using the XCAL software (see article below)
to perform their own simulations if they so desire. However, until the
focus has been stabilized, and some preliminary science observations
have been performed, this information should be considered tentative.
Around the end of September, a more detailed technical assessment of
how the spherical aberration will affect each instrument will be sent
to the GOs. In addition, a workshop will be held at STScI to provide
observers with up-to-date information (see below). The GOs will then
have about a month to make their final categorizations of their
programs. In many cases observers may want to contact the instrument
scientists for advice. If the observer believes the program is still
viable, he or she may want to suggest modifications, possibly
including allocation of additional spacecraft time. The STScI
instrument scientists will review the GOs' suggested modifications for
technical feasibility and their report will be included in the
information the TAC uses for its deliberations.
   The TAC will reconvene around the end of November to consider the GOs'
evaluations of whether their programs are still viable, and to
evaluate requests for additional spacecraft time. Their
recommendations will be forwarded to the STScI Director, and the GOs
will be informed of the decision in December. If the requested
modifications are approved, the GOs will have about a month to modify
their proposals using the Remote Proposal Submission System (RPSS).

 -  Duccio Macchetto andJBradJWhitmore

7.     CYCLE 2 DEADLINE POSTPONED
The procedure for submitting Cycle 2 proposals will not be greatly
affected by the reassessment of Cycle 0 and Cycle 1 programs. However,
the proposal deadline will be delayed so that at least two months
elapse between the resubmission of modifications to Cycle 1 programs,
and the Phase I deadline for Cycle 2 proposals. This implies a
deadline for Cycle 2 proposals no earlier than about February 15, 1991
(instead of the previously announced November 15, 1990).
 -   Duccio Macchetto and Brad Whitmore

8.     USERS' WORKSHOP SCHEDULED FOR OCTOBER
As part of the process (described above) of reassessing the accepted
Cycle 1 observing proposals, STScI is developing plans for a Users'
Workshop to provide the latest HST and SI information to observers,
and to provide an opportunity for GOs and GTOs to discuss their
programs directly with STScI staff.
    Topics will include up-to-date information on the point-spread
function, an update on actual instrumental capabilities, possible
deconvolution techniques, the proposal-processing timeline and
procedures, TAC policies, and budget considerations. A two-day meeting
is tentatively being considered for early October, but a date will not
be set until after most of the SAT observations are completed (see
article 5).
   The exact dates and further details will be sent to observers in the
near future, and will be also be announced in the STScI Electronic
Information Service. Please contact the User Support Branch
(800-544-8125 within the U.S. or 301-338-4413; userid USB) for further
information if you are interested in participating in this workshop.
 - F. Duccio Macchetto andJBradJWhitmore

9.     RECONSTRUCTION OF HST IMAGES
STScI is actively exploring ways to apply the tools of image
restoration to HST data, both images and spectra, in order to correct
for the spherical aberration of the telescope optics. While the
sensitivity for the faintest objects is lost for the time being, there
is every reason to expect that the images and spectra of brighter
objects can be computer-restored to the resolution offered by the
nearly diffraction-limited RcoreS of the HST point-spread function
(PSF). There are several linear and nonlinear techniques being used by
Institute scientists in numerical experiments, and we are now
beginning to apply these techniques to real HST data (see next
article).
   We are finding interesting and fertile ground for interactions between
radio and optical astronomers on these problems. Radio astronomers
regularly apply some of these techniques (e.g., CLEAN and MEM) in
their image reconstructions. However, they rarely deal with PSFs that
vary over the field, with detectors whose intensity response is not
linear, or with noise that is signal-amplitude dependent. Optical
astronomers have used some of these methods in 1-D spectral
deconvolution (e.g., the RFourier-quotientS method), but have been
limited in 2-D restorations by the stochastic nature of the seeing.

An informal workshop on the restoration of HST images and spectra was
held at STScI on August 21-22. Please contact Rick White
(301-338-4797; userid WHITE) for further information.
A working group on deconvolution has been formed to coordinate the
efforts of several staff scientists and engineers who have started
work on these topics. For the near future our plans involve obtaining
additional real data on which to apply the various existing
techniques, and also experimenting further with new algorithms. We
want to encourage members of the astronomical community who are
interested in these matters to send us their comments and suggestions,
preferably by e-mail, to Bob Hanisch (301-338-4910; userid HANISCH)
for imaging applications, or to Ron Gilliland (301-338-4454; userid
GILLIL) for spectra.
Finally, it is important to evaluate the implications of extensive use
of restoration algorithms upon the computing resources that can be
made available for HST data analysis. If restoration is to be carried
out routinely on HST images and spectra, we shall have to take account
of it in our plans for future improvements to the Institute's
computing hardware and to the STSDAS software. Please e-mail your
thoughts on this topic to Ron Allen (userid RJALLEN).
 -  Ron Allen

10.    WF/PC IMAGERY OF 30 DORADUS
As part of the observing program of the Goddard High Resolution
Spectrograph Investigation Definition Team (IDT), a short exposure on
the 30 Doradus region of the Large Magellanic Cloud was obtained with
the Wide Field and Planetary Camera (WF/PC) on August 3. This image,
already widely distributed by the news media, provides a dramatic
example of the scientific capabilities that HST retains.
The 30 Doradus Nebula in the LMC is the largest H II region known in
the Local Group of galaxies. It contains a spectacular cluster of
early-type stars, including many of type O3, the earliest known.
The cluster is centered on the luminous object R136, whose nature has
been controversial until quite recently. In the early 1980Us, several
investigators suggested that R136 might be a single supermassive
object, of up to 3000 solar masses.
   More recent ground-based studies, however, have resolved R136 into a
multiple system, using techniques of maximum-entropy image
deconvolution (which achieved a resolution of 0".4 over the whole
field), and speckle interferometry (which achieved 0".1 resolution for
the inner few arcseconds). The combined analyses resolved 27
components within R136, the brightest of which are similar to stars in
the surrounding cluster, and are the best current candidates for the
most massive stars known (250 solar masses, if they are single
objects).
   In the accompanying figure, panel A shows a 900 x 900-pixel subsection
of the full WFC frame. The exposure time was 40 seconds, through the
F368M filter. Panel B is a 90 x 90-pixel (9" x 9") enlargement of the
same frame. Because of the 0".1 cores of the stellar imagesQwhich are
achieved over the entire frameQthe components seen from the ground
only with speckle interferometry are seen directly with HST. These
sharp cores, however, are surrounded by diffuse halos due to the
spherical aberration of the HST optics. In the central region of R136,
these halos overlap to produce a diffuse background.
Panel C, for comparison, shows a ground-based image of R136, obtained
by Georges Meylan (STScI) with the 2.2-m Max Planck telescope at the
European Southern Observatory. The FWHM of the stellar profiles in
this image is 0".6, and it is not possible to distinguish individual
components within the central portion of R136.
    Finally, panel D shows the result when an image-reconstruction
techniqueQin this case the Lucy iteration, as carried out by the WF/PC
IDTQis applied to the raw HST image of panel B. More than twice as
many stellar components within R136 as previously known are now
visible, because of the wider field at this resolution and larger
dynamical range as compared to the ground-based speckle work.
Since the HST frame was taken in near-ultraviolet light, most of the
resolved stellar images correspond to hot, massive stars. Moreover,
several of the O3 supergiants still appear as single images at 0".1
resolution, strengthening the probability that they are single objects
of up to 250 solar masses. The considerable scientific return from this early,
single WF/PC image illustrates the significant capabilities that HST
possesses in spite of its optical problems.

11.     XCAL
XCAL is a software tool developed by Keith Horne for calculating
exposure times and count rates for each of the scientific instruments.
The program can be run with a wide variety of assumed astronomical
sources as input. Scientists in the Telescope and Instruments Branch
are in the process of updating XCAL with the current telescope PSF.
Our aim is to make XCAL available for GOs and GTOs to use during
August and September for precise recalculation of exposure times. A
full description of the software and procedures for using the tool
will be provided in our STScI Electronic Information Service and in
the next Newsletter.
 -  Chris Blades

12.     INSTRUMENT NEWS
12.1    WF/PC
Following the initial internal-calibration data frames, the Wide Field
and Planetary Camera (WF/PC) took the first-light HST image on May 30,
1990, a picture distributed world-wide. All eight CCDs and camera
heads are working just as they were before launch, and the WF/PC is
being used to support the current testing and evaluation of the OTA,
as well as the OV and science assessment programs. The CCDs were
cooled to a nominal temperature of P82! C early in the mission in
order to support focus tests, and have since been cooled to P97! C,
following high-temperature decontamination. Monitoring of the internal
contamination (affecting performance in the far UV, below 2000 ) is
continuing. The CCDs have not yet been UV-flooded.
The following camera features have been tested and found to be
satisfactory:
(1) the pyramid has been rotated from WFC to PC and vice versa many
times;  (2) internal fiducial (Kelsall) lamp exposures have
demonstrated internal focus;  (3) CCD thermal control and stability
have been achieved at P97! C;  (4) several filters have already been
used, including F336W, F555W, and F785LP (approximating U, V, and I);
 (5) CCD read noise and bias level are roughly the same as pre-launch
values; (6) the quantum efficiency (in V) appears to be in rough
agreement with non-UV-flooded pre-launch values;  (7) the background
cosmic-ray rate agrees with pre-launch expectations.
 -  Richard Griffiths

12.2    WF/PC II
Prior to the discovery of the Optical Telescope Assembly (OTA)
aberration, WF/PC II was scheduled for installation during a
refurbishment mission approximately three years after launch of HST.
The schedule for construction of the new camera at the Jet Propulsion
Laboratory (JPL) is presently under review, but completion will
probably still occur in the latter half of 1992.
The HST aberration recovery plan includes modifications to the optics
of WF/PC II such that the original specification for the OTA/camera
system is met. To achieve this, optics teams have been convened at JPL
and elsewhere in order to measure the as-built OTA aberrations and to
define the changes needed to the WF/PC II optics in order to
compensate fully for the problem. In the near term, a suite of HST
observations will be performed in order to characterize the OTA, and
as soon as these measurements are completed, the WF/PC II optical
components will be figured. On the assumption of a simple spherical
aberration in the primary mirror of the OTA, for example, the required
changes could be effected in the figures of the Cassegrain repeater
secondaries (and possibly the fold mirrors) of WF/PC II.
When built, WF/PC II will be tested with an optical stimulus which
will be modified so as to reproduce the actual performance of the OTA.

Other changes and developments on WF/PC II, relative to the present
camera, were described in the March 1990 Newsletter. New developments
include the following:
1. An internal flat-field capability (in the UV and visible) will be
provided by the inclusion of deuterium and quartz lamps within the
volume of the current UV light-pipe.
2. The first flight-quality CCDs have been selected, and show
excellent performance and stability.
3. Contamination control includes increased venting of electronics
bays, baffling of CCDs, changes to materials, and the inclusion of CCD
boil-off heaters in order to provide sensitivity down to Lyman alpha.
4. A preliminary filter list appeared in the April 1986 Newsletter;
the revised list will be published in an upcoming Newsletter.
5. Changes to the electronics will result in elimination of missing
code from the analog-to-digital converter, as well as the elimination
of residual images and improvement in full well capacity of the CCDs.
In the on-chip (2 x 2) binning mode, an extended register will be
provided for determination of bias.
 -  Richard Griffiths

12.3    FOC
The Faint Object Camera (FOC) was turned on for the first time on May
13. Both the f/48 and f/96 relays were exercised by taking darks and
flats with the on board LEDs in extended format. The data obtained
from these tests indicate that the FOC is operating flawlessly. The
dark-count rate has increased from what it had been on the ground, but
is still low. The dark count rate for f/96 is 6.7 x 10 P4 counts pixel
-1 s-1 for normal pixels and for f/48 it is 1.9 x 10 P3. The standard
deviation of the dark count between different exposures is
approximately 2.6 x 10 P4 in both cases. These results hold only for
exposures taken out of the South Atlantic Anomaly region that is
capable of driving the FOC into saturation.
   The spatial response (flat field) of the f/96 detector is very similar
to what was seen on the ground. Generally, the relative spatial
response is within 10% of that seen in the ground-based exposures. The
spatial response of the f/48 detector has changed somewhat; the
response seems to have fallen in the corners relative to the
ground-based exposures by up to 30%. The reason for this discrepancy
will not be known until external illumination flats using the Earth
and the Orion nebula are taken later on in the Orbital and Science
Verification programs.
   Following turn-on, a series of stability tests was carried out. The
objective of these tests was to map any temporal variation in the
distortion pattern in each detector, over a prolonged period of time.
Beginning from the time that the high voltage (HV) was switched on,
each test ran for approximately 13 hours and consisted of 36
full-format (512 zoom x 1024) 900-second internal flat fields.
Although none of the flat fields were saturated, the resulting images
had a relatively low signal-to-noise, approximately 28 counts per
pixel on the f/48 images, and 37 counts per pixel on the f/96 data.

  The first step in the analysis procedure is to define a benchmark
against which variation can be measured. For this, we define the
RstableS reseau grid pattern as being the average of the final 10
exposures. The stability effects are then mapped by determining, for
each image, how the observed reseau grid differs from this RstableS
reference grid. The analysis was carried out in three identical stages
for each relay by first analyzing all 36 images individually, stacking
the images in sets of four to improve the signal-to-noise, and then
reanalyzing. Finally, the central 512 x 512 regions of the smoothed
images were extracted, and reanalyzed.
   As the primary indicator of stability, we have used the RMS radial
residual (defined as the RMS radial difference between the RobservedS
reseau positions and the RstableS reseau positions), since this
represents the limit to which geometric correction can be done in the
RSDP pipeline. The analysis indicates that the RMS error in the reseau
positions over the full extended 512 zoom x 1024 fields ranges from
about 1 pixel (about 1.5 pixels for f/96) at HV+75 minutes, to about
0.3 pixels at HV+500 minutes. Note that this represents a significant
improvement over the results from the RrawS data, where the
signal-to-noise is very low. Further, when we examine the central
regions of these images we obtain RMS residuals of only about 0.5-0.2
pixels because the stabilization effects are mainly rotational; the
shorter distance from the center of rotation results in smaller
residuals.
   To summarize, the tests indicate that there are clear stabilization
effects occurring in the detectors, but that these effects are small.
The implications for geometric correction are that over the whole 1024
x 1024 field the correction is reliable to about 0.6 of a pixel, and
this can be interpreted as a reliability of about 0.25 pixels within
the central 512 x 512, and about 0.8 pixels outside this region.
The Rfirst-lightS sequence of images for the FOC was obtained on June
17. The target was an astrometric standard field in the open cluster
NGC 188. Ten images were obtained, and two of these have been examined
to make a preliminary assessment of the absolute sensitivity of the
FOC and to examine the structure of the PSF. Stars 54 and 51 were the
primary target stars. These are 15th-magnitude G and K stars that were
observed using the F430W filter and six magnitudes of neutral-density
attenuation.
   The observed count rates were compared to a simulation in which it was
assumed that star 54 is a G2 V star and 51 is a K2 III star. The
throughput curves for each optical component in the light path and the
detector DQE profile were multiplied together and convolved with
comparison-library spectra to provide estimated count rates. The
observed stellar surface brightness and integrated counts were
obtained by deriving the mean counts in circular annuli of 1 pixel
width (0".02).
    The encircled integrated counts as a function of radius were then
divided by the predicted total counts, to produce the encircled-energy
plots shown in the figure. The top curve is the pre-launch prediction.
Below that are the observed curve for star 51 and two observed curves
for star 54 (which agree with each other rather well). These profiles
show 20% of the flux inside a radius of 0".1, with approximately
exponential wings beyond about 0".3. The total flux seems to converge
between 2" and 2".5 radius. This is very similar to the Planetary
Camera images taken just two days earlier. The diffuse halo arises
from defocussing and optical aberrations in the HST image. The core is
very sharp and has a FWHM of 0".066.
   In absolute terms, star 51 converges to 100% of the predicted counts,
and star 54 to about 84% of the prediction. This is good news for the
FOC. The uncertainty in stellar spectral type is such that a small
difference in the actual spectral type compared to the assumed, say a
change of 0.1 in BPV, can give rise to relatively large (20% or so)
changes in the estimated counts. This is due to the very steep
fall-off to the blue in the 4300  spectral region for stars of G and
K spectral type. The difference between the two stars is therefore
well within the uncertainties of the analysis, and the overall
observed count rates are quite consistent with our ground-based
predictions.
   In conclusion, although the HST image quality at the time of
observation suffered various defects, the overall throughput and
sensitivity of the FOC are close to expectation. A higher S/N image
taken three weeks later confirmed the basic shape of the
encircled-energy curve. In addition, it shows complex structure very
similar to the tendrils seen in WF/PC images. Preliminary
investigations indicate that the energy within the sharp core may be
sufficient to recover much of the hoped-for resolution of HST.

 -  Francesco Paresce, Bill Sparks, Dave Baxter, and Perry Greenfield.

12.4    FOS
The Faint Object Spectrograph (FOS) is in generally good health; all
mechanisms, calibration sources, and both detectors appear to be
operating as expected, although many checks and calibrations remain to
be performed before the FOS will be ready for science observations.
In-orbit testing of the FOS has progressed rather slowly, due
primarily to scheduling difficulties and the need to exercise caution
in the initial detector high voltage turn-on. Tests have shown that
the detector voltage can be left on during SAA passage, and some
internal-calibration and target-acquisition observations may even be
possible through the SAA, greatly simplifying scheduling and improving
the efficiency of FOS utilization.
   A problem involving spurious resets of the onboard blue-side
microprocessor is being investigated. Changes to the standard FOS
command sequences are expected to correct the reset problem fully; the
blue-side calibration program, which has been suspended pending
resolution of the anomaly, should resume in mid-August. Internal
calibration-lamp observations indicate that the FOS throughput,
including that in the far UV, is nominal. However, the degraded
point-spread function from the telescope will generally require
significantly longer exposure times for most FOS observations, and
will render intractable most programs dependent on high spatial
resolution.
 -  George Hartig

12.5    GHRS
High voltage has been turned on for both of the Goddard High
Resolution Spectrograph (GHRS) Digicon detectors, and both are
operating well. Series of dark counts have been taken, and the rates
are typically 6 x 10^3 counts/ diode for Digicon 1, and about
50% higher for Digicon 2. When HST passes through the center of the
SAA, radiation increases the dark-count rate to a maximum of about 0.5
counts sP1. This means that high voltage can be left on inside the SAA
and that bright targets may be observable there.
The GHRS has now observed the Earth through each of its science
apertures in order to determine their relative locations. Results so
far indicate little change relative to measurements made on the
ground; the instrument seems electronically and physically stable.
Tests scheduled in the immediate future include observations of stars
of known position in the field of NGC 188 to relate the GHRS aperture
positions to spacecraft coordinates, and the first spectra of the
internal calibration lamps. Spectra of the first external targets are
perhaps one month away.
  A major effort is underway to evaluate the expected effects of the
degraded HST focus on the performance of the GHRS. Expectations at
present are the following:
1. Observations through the Large Science Aperture (LSA) will suffer
relatively little throughput loss compared to previous expectations,
but will produce about a factor of two less spectral resolution on
point sources. The instrumental response will have a narrow core and
much broader wings than expected, although this effect will be less
extreme than on the imaging instruments, since the GHRS diodes are
2".0 high and capture most light spread perpendicular to the
dispersion. The significant wings on the instrumental profile will
affect attempts to determine accurate line profiles, however.
2. Observations through the Small Aperture will produce the originally
expected sharp resolution, but will suffer a light loss of a factor of
four to eight.
3. Target acquisition will work almost exactly as originally planned
for isolated targets, but the count rates will be about a factor of
two smaller. Tests on crowded fields are planned.
4. Maps made of the LSA with the focus diodes will produce count rates
about a factor of five less than originally expected.
 -  Doug Duncan

12.6    HSP
The High Speed Photometer (HSP) team reports that the testing of the
HSP has generally gone well to date. Dark counts have been measured on
the four image-dissector tubes and are nominal. All of the HSP
electronic systems are performing well, and the thermal behavior of
the instrument is as expected. There is one significant anomaly: when
the high voltage is switched on for the photomultiplier (PMT), the
count rate rises from 200 counts sP1 to 2000 counts sP1 over a
40-second interval. This problem is not understood, but the best guess
is that it will not occur when the PMT is operated at its normal
voltage. Further tests should soon confirm this suggestion.
   The effect of the spherical aberration on HSP performance is still
under study, but initial calculations indicate that the large images
may lead to long-term (weeks to years) photometric errors of 1% and
short-term (seconds to weeks) photometric errors of about 0.1%. The
science that can be done with the HSP is thus significantly degraded.

 -  Richard L. White

12.7    FGS
The Fine Guidance Sensors (FGS) have been used in Coarse Track, Fine
Lock, Map Mode, and Line-of-Sight Scan. The stable Fine Lock guiding
performance of the FGS is at the 0".005-0".007 level, as was expected.
This performance, of course, is not achieved during the terminator
crossings as discussed above, but revisions to the Pointing Control
System control law for the gyros are expected to minimize these
disturbances.
   In addition, before launch a hardware/software laboratory test of the
enhanced Coarse Track guiding procedure discussed in the last issue of
the Newsletter was successfully carried out. Finally, there is a minor
problem with the Fine Guidance Electronics unit. Its main memory was
not radiation-shielded when it was constructed and it is susceptible
to single bit flips when hit by high-energy protons such as those that
penetrate the SAA. This problem can not be cured without a replacement
of the unit, but it can be ameliorated by continuously updating the
Fine Guidance Electronics unit memory from the DF-224 computer onboard
the spacecraft. This is already being done.
   The calibration and scientific capabilities of the FGS are starting to
be assessed through activities scheduled to occur during the second
part of the Orbital Verification phase. Additional information and
characterization will come during the Science Verification tests and
calibration tests planned for the FGS.
 -  L. G. Taff

13.    STSDAS News
Version 1.1 of the Space Telescope Science Data Analysis System
(STSDAS) was released in May, and shipments of the software, test data
sets, and documentation have been going on during June and July. Many
sites have made use of our anonymous ftp service (the STScI Electronic
Information Service) to download the installation, saving us the
trouble of making tapes and those sites the trouble of waiting for
them. Because of the convenience to everyone concerned, we strongly
encourage sites that can use anonymous ftp to do so. The installation
instructions (also available via ftp) include a section on how to
reassemble the software from the ftp directories.
   At this time we have not set a firm date for the next STSDAS release,
although we expect it to be sometime in the spring of 1991. Given the
problems with the HST image quality, we will be investing a good deal
of effort toward having one or more image-deconvolution techniques
available for use. The STSDAS group has been working in conjuction
with other scientists at STScI to evaluate various deconvolution
algorithms to see which work best with HST data, and what
modifications need to be made to handle the HST point-spread function.

   The first IRAF workshop is tentatively scheduled for the fall of 1991.
This workshop will be jointly sponsored by the National Optical
Astronomy Observatories (NOAO), the Harvard-Smithsonian Center for
Astrophysics (CfA), and STScI, and will feature both invited talks and
contributed papers. The specific agenda has not yet been set, but the
emphasis is likely to be on data-analysis algorithms and techniques,
with several special-interest sessions concentrating on the STSDAS HST
analysis software and the CfA ROSAT analysis software. The NOAO IRAF
Newsletter is the primary source of information about this workshop,
but we will try to keep readers apprised of the general plans in this
Newsletter as well.
  -  R. J. Hanisch

14.    EDUCATIONAL PROGRAMS AT STScI
During the past few years, we have established a small but substantive
educational and public-outreach program at STScI. Recently, our
programs have become partly supported by the newly established Johns
Hopkins Space Grant Consortium, wherein STScI has joined forces with
JHU, its Applied Physics Lab, and Morgan State University to enhance
the study of space science at all levels. Our programs generally fall
into three categories:
 1. Public Outreach. The STScI public-outreach program actively
involves many staff members. This is best exemplified by our Speaker's
Bureau, which currently sends technical staff into the surrounding
schools and civic organizations at the rate of about one per day.
To satisfy the general public's thirst for information about the HST
mission, we have for several years conducted an Open Night at the
Institute. On the first Tuesday evening of every month, a staff
scientist gives a talk, followed by a video and an opportunity to view
the heavens through small telescopes mounted by amateur astronomers of
the Baltimore Astronomical Society.
   The annual Hubble Lecture occurs each November 19, the date of Edwin
Hubble's birthday, and is given by an eminent space scientist. This
lecture usually attracts close to a thousand people.
  2. Educational Programs. Many of our formal educational efforts are
directed toward pre-college teachers, attempting to activate the
RmultiplierS effect whereby teachers can amplify what they learn among
their classes and school systems. STScI annually conducts several
Teacher Workshops, some only for a day's duration during the academic
year, others more intensively for a week during the summer. Generally
limited to 30 teachers apiece, our workshops are usually offered for
high-school science teachers. We have also been leading some workshops
for Baltimore's middle (and even elementary) schools. Last month,
under the auspices of the JHU Space Grant Consortium, we directed a
4-day conference that attracted some 300 teachers from nearly every
state.
   Teachers, especially those who have attended our workshops, are
encouraged to return to STScI with their classes. A lecture is
presented on the HST mission, a staff member addresses them about
careers in science and technology, and the students leave with some
materials useful to them in their studies.
   Since our teacher workshops are heavily oversubscribed, with many
hundreds of teachers being turned away annually, we have captured the
essence of a typical workshop in a Teacher's Kit. The kit includes
slides, posters, videos, hands-on activities, glossaries, and a wealth
of brochures describing, predominantly, the HST science mission.
Led by Morgan State and other members of the JHU Space Grant
Consortium, STScI is supporting a Teacher Training Program for Women
and Underrepre-sented Minorities. The program, designed to encourage
women and minorities to pursue careers in science and engineering,
begins by identifying talented students at the high-school level,
designating them Rspace scholars,S tracking and supporting them
through college and even, perhaps, graduate school. Enrichment
programs at STScI, Applied Physics Lab, and many other local area
technical organizations are made available to these students
throughout their schooling days.
 3. Video as a Teaching Aid. We are also developing video programs that
can be used in the classroom.
   Some years ago, we established an Astronomy Visualization Laboratory
and equipped it with an array of computer graphics devices that can
produce broadcast-quality animation. With an artist in the pilot seat
of a Silicon Graphics 3130-4D Workstation, and a scientist in the
co-pilot's seat, we are building a Video Library of short animations
covering the spectrum of astronomical knowledge. Actually, three
libraries are being readied: one for astronomy in general, another
specifically for the HST mission, and a third that addresses
fundamental principles of physics. In this Lab we are also preparing
Rvideo bitesS Q 20-second video clips that highlight the early images
and data to be released from HST; these then form the basis for video
press releases that accompany the more standard, hardcopy press
releases.
   STScI is co-producing with Maryland Intec (the instructional arm of
Maryland Public Television [MPT]) a 32-part instructional television
program on astronomy. Called RStarfinderS and beginning in the fall of
1990, this series of weekly shows, filmed at STScI and MPT, will
present basic space science to middle-school (7-10) grades where we
believe the need is greatest, will highlight some of the results from
the HST mission, and will include a short segment about careers in
science and technology. These programs will be transmitted weekly for
schools throughout the state of Maryland, and via the PBS network for
distribution nationwide (and into Europe as well).
   At STScI, we are building an Orbital Status Display Board to provide
real-time display of HST activities. Driven by a personal computer and
time-tagged to HST's observing calendars that are built at STScI, this
display can show virtual real-time activities of the HST mission.
Other monitors surrounding the real-time display show the latest
imagery released into the public domain and also highlight the inner
workings of HST and its scientific instruments. The prototype of this
board is now up and running in the STScI lobby, and eventually will
become exportable to other locations, including major science museums
around the nation.
   Since STScI is a research/operations center not readily accessible to
the general public, we have developed an official STScI Visitor Center
at the Maryland Science Center in Baltimore's Inner Harbor. There we
have helped to mount exhibits and planetarium shows on the HST
mission, and we are jointly sponsoring a number of additional
educational programs at the pre-college level.
 -  Eric J. Chaisson

15.    HUBBLE FELLOWSHIP PROGRAM
The selection process for the first year of the Hubble Fellowship
Program has been completed. The awardees, selected from a pool of 110
highly qualified candidates from 25 countries, and their Host
Institutions, are listed below. Their appointments will commence in
the fall of 1990.
  Contingent on funding from NASA, up to 15 new Hubble Fellows will be
selected this winter for terms beginning in the fall of 1991. A formal
Announcement of Opportunity was issued recently, and the application
deadline is November 16, 1990.
   The main objective of the program is to provide recent postdoctoral
scientists of unusual promise and ability with opportunities for
carrying out HST-related research. A qualifying host institution must
be a non-profit U.S. organization where HST-related science can be
carried out successfully. Applications will be accepted from
candidates of any nationality who have earned their doctorates after
January 1, 1988, in Astronomy, Physics, or related disciplines.
The duration of a Fellowship is a total of three years, which includes
an initial period of two years and an extension of another year, which
is granted after a positive mid-term review.
The detailed Announcement of Opportunity, including the application
instructions, is available upon request from the Hubble Fellowship
Program Office at STScI (userid HFELLOWS).
 -  Nino Panagia

16.    INSTITUTE NEWS
16.1    SABBATICAL VISITORS AT     STScI
In order to promote exchange of ideas and collaborations in
HST-related science, STScI has limited funds available to support
visiting scientists who wish to spend extended periods of time (3 to
12 months), typically on sabbatical leave from their home
institutions, conducting research at the STScI. In general, Sabbatical
Visitors will have the status of STScI employees and will have access
to the facilities available to staff members of the STScI.

  Established scientists who are interested in this opportunity should
send a letter specifying the proposed period of time and any other
relevant details to the Visiting Scientist Program, c/o Nino Panagia
at STScI. In general, letters should be received at least 6 months
before the starting date of the proposed visit. For fiscal year 1991,
up to 1 FTE can be supported under this program. In view of the short
notice, letters from scientists who wish to start their visits as
early as January 1, 1991, will be considered if received by October 1,
1990.
 -  Nino Panagia

16.2    ESA FELLOWSHIPS
Astronomers of European Space Agency (ESA) member countries are
reminded of the possibility of coming to work at STScI as an ESA
Fellow. Prospective fellowship candidates should aim to work with a
particular member or members of the staff at STScI; for this reason,
applications must be accompanied by a supporting letter from STScI.
Details of the interests of staff members at STScI can be obtained
from Dr. J.E. Pringle (301-338-4477; userid PRINGLE) at STScI.

  Details of the fellowships and applications procedures can be obtained
from the Education Office, ESA, 8-10 rue Mario Nikis, 75738 Paris 15,
France. Completed application forms must be submitted through the
appropriate national authority, and should reach ESA no later than
March 31 for consideration in May, and no later than September 30 for
consideration in November.

16.3    THE MAY 1990 WORKSHOP
The 1990 STScI May Workshop, on Massive Stars in Starbursts,S was
attended by about 100 enthusiastic participants, who heard 18 reviews
and viewed 40 posters covering most aspects of current research on
massive stars and extragalactic starbursts, and engaged in extensive
discussions across the two disciplines. Following an introductory
survey by C. Leitherer, P. Conti and R. Humphreys reviewed current
knowledge of the spectra of massive blue and red stars, respectively,
from the UV through the IR.  R. Kudritzki then presented the state of
the art in modeling of hot atmospheres, and A. Maeder did the same for
massive stellar evolution, while C. Garmany reviewed the most recent
information on the composite HR diagram and IMF of massive stars in
the Galaxy and Magellanic Clouds. I. Gatley presented a tantalizing
introduction to future studies of massive star formation by means of
high-resolution IR arrays.
    The next session focused on massive young regions and
stellar/interstellar interactions, with presentations by N. Walborn on
30 Doradus, R. Kennicutt on the general properties of giant H II
regions, and R. Chevalier on SN and SNR. The extragalactic review
component began with surveys by T. Thuan of blue compact dwarf
galaxies, by G. Rieke of M82 as paradigm, and by B. Rocca-Volmerange
of population synthesis models for starburst galaxies. N. Scoville
then reviewed the interstellar medium and R. Joseph the stellar
content of starburst galaxies, while C. Norman discussed models for
these phenomena. In the final session, T. Heckman addressed the
starburst-AGN connection, and D. Weedman presented a review of the
cosmological significance of starbursts.
    There was ample evidence that the original intent of stimulating
interaction between the two disciplines substantially succeeded, with
both stellar and extragalactic participants frequently expressing
interest and even amazement at the results and dilemmas of their
counterparts. This interaction will be recorded for the benefit of a
wider audience in the Workshop proceedings, which will contain the
reviews plus discussions and be published by Cambridge University
Press in the STScI series format. The poster papers will be circulated
separately to participants and major astronomical libraries.
 -  Nolan R. Walborn

16.4    STScI PREPRINTS
The following papers have appeared recently in the STScI Preprint
Series. A list of current preprints is also posted on the STScI
Electronic Information Service and is updated monthly. Copies of
preprints may be requested from Sharon Toolan (301-338-4898; userid
TOOLAN) at STScI; please specify the preprint number when making a
request.
411. "Distances of Galactic WC Stars from Emission-Line Fluxes and a
Quantification of the WC Classification",S L.F. Smith, M.M. Shara, and
A.F.J. Moffat.
412. "Photometry and Gas Kinematics of the Spiral Galaxy NGC 1566",S
W.D. Pence, K. Taylor, and P. Atherton.
413."Massa's Star, HD 93840: A New Extreme BN Supergiant,S N.R."
Walborn, E.L. Fitzpatrick, and J. Nichols-Bohlin.
414. "Contemporary Optical Spectral Classification of the OB Stars: A
Digital Atlas,S N.R." Walborn and E.L. Fitzpatrick.
415. "Stellar Absorption Features in High-Redshift Radio Galaxies",S
K.C. Chambers and P.J. McCarthy.
416. "The Origin of the Mass, Disk-to-Halo Mass Ratio, and L-V
Relation of Spiral Galaxies", K.M. Ashman.
417. "A Study of the Baldwin Effect in the IUE Data Set", A.L. Kinney,
A.R. Rivolo, and A.P. Koratkar.
418. "IRAS Galaxies and the Large-Scale Structure in the CFA Slice",
A. Babul and M. Postman.
419. "Discovery of a Third, Inner Light-Echo Ring around Supernova
1987A", H.E. Bond, R. Gilmozzi, M.G. Meakes, and N. Panagia.
420. "Star-Forming Galaxies and the X-Ray Background", R.E. Griffiths
and P. Padovani.
421. "The Science Mission of the Hubble Space Telescope", E.J.
Chaisson and R. Villard.
422. "Soft X-Ray Properties of Seyfert Galaxies I. Spectra", J.S.
Kruper, C.M. Urry, and C.R. Canizares.
423. "Galaxy Interactions and the Stimulation of Nuclear Activity,"
T.M. Heckman.
424. "What the Longest Exposures from the Hubble Space Telescope Will
Reveal", J.N. Bahcall, P. Guhathakurta, and D.P. Schneider.
425. "Binaries in Globular Clusters: Outburst and Quiescence Spectra
of Three Cataclysmics," M.M. Shara, A.F.J. Moffat, and M. Potter.
426. "1) Cool Infalling Gas and Its Interaction with the Hot ISM of
Elliptical Galaxies", W.B. Sparks and F.D. Macchetto. 2) "RDust and
Ionized Gas in Active Radio Elliptical Galaxies", D.A. Forbes, W.B.
Sparks, and F.D. Macchetto. 3) "RIC 5063: A Merger with a Hidden
Luminous Active Nucleus", L. Colina, W.B. Sparks and F. D. Macchetto.
427. "The Peculiar Off-Centered Ring of the Sa Galaxy NGC 3611,"F.
Schweizer and P. Seitzer.
428. "Chaotic Orbits in Barred Galaxies with Central Mass
Concentrations", H. Hasan and C. Norman.
429. "Kinematics of Chromospherically Active Late-Type Dwarfs in the
Solar Neighborhood", D.R. Soderblom.
430. "Catalog-to-Catalog Reductions", L.G. Taff, B. Bucciarelli, and
M.G. Lattanzi.
431. "RR Lyrae Stars in Local Group Galaxies. II. NGC 147", A. Saha,
J.G. Hoessel, and A.E. Mossman.
432. "The Evolution of Angular Momentum in Solar-Mass Stars", J.R.
Stauffer and D.R. Soderblom.
433. "4C 41.17QA Radio Galaxy at a Redshift of 3.8", K.C. Chambers,
G.K. Miley, and W.J.M. van Breugel.
434. "The cD Galaxy in Abell Cluster 1775", J.J.E. Hayes and B.
Bhattacharya.
435. "On the Feasibility of Detecting Extra-Solar Planets by Reflected
Starlight Using the Hubble Space Telescope", R.A. Brown and C.J.
Burrows.
436. "The Surface-Brightness Test for the Expansion of the Universe.
II. Radii, Surface-Brightness, and Absolute-Magnitude Correlations for
Nearby E Galaxies", A. Sandage and J.-M. Perelmuter.
437. "Spectroscopic Authentication of Very Old Nova Candidates", M.M.
Shara, A.F.J. Moffat, and M. Potter.
438. "Dissipation in Barred Galaxies: The Growth of Bulges and Central
Mass Concentrations", D. Pfenniger and C. Norman.
439. "On Mass Transport in Nonviscous, Nonself-Gravitating Fluid
Disks", S.H. Lubow.
440. "Nitrogen in Irregular Galaxies", D.R. Garnett.
441. "An Analysis of the Hubble Space Telescope Fine Guidance Sensor
Coarse-Track Mode", L.G. Taff.
442. "On the Nature and Implications of Starburst-Driven Galactic
Superwinds", T.M. Heckman, L. Armus, and G.K. Miley.
443. "Core Velocity Dispersion and Mass-to-Light Ratio of the Old
Magellanic Globular Cluster NGC 1835", P. Dubath, G. Meylan, M. Mayor,
and P. Magain.
444. "Optical Spectroscopy of the High-Latitude Cloud L1569", B.E.
Penprase, J.C. Blades, A.C. Danks, and P. Crane.
445. "Doppler Imaging of the Dwarf Nova U Gem", T.R. Marsh, K. Horne,
E.M. Schlegel, R.K. Honeycutt, and R.H. Kaitchuck.
446. "Weighted Slit Extractions of Spectral Data", A.L. Kinney, R.C.
Bohlin, and J.D. Neill.
447. "The Optical Emission-Line Nebulae of Powerful Far-Infrared
Galaxies", L. Armus, T.M. Heckman, and G.K. Miley.
448. "The Pulsating Nucleus of the Planetary Nebula Longmore 4", H.E.
Bond and M.G. Meakes.
449. "Changes in the Orbital Periods of Close Binary Stars", T.R.
Marsh and J.E. Pringle.

16.5    STAFF NEWS
C. Megan Urry, a postdoctoral fellow at STScI, has been awarded the
1990 Annie Jump Cannon Award in Astronomy. The award is administered
by the American Association of University Women, in cooperation with
the American Astronomical Society. Dr. Urry is well known for her
research in the area of multiwavelength studies of active galactic
nuclei. This coming fall, she will become an Assistant Astronomer in
the User Support Branch.
  Abi Saha has been appointed Assistant Astronomer in the User Support
Branch.
  Charles R. Proffitt has joined the Institute as an STScI postdoctoral
fellow. Previously at the Universite de Montreal, he specializes in
theoretical studies of stellar structure, evolution, and pulsation,
with a particular interest in mixing, abundance anomalies,
gravitational diffusion, and turbulence.
  Nolan R. Walborn has been named Head of the Science Program Selection
Office.

16.6    STScI ELECTRONIC INFOR-MATION SERVICE
The March 1990 issue of the Newsletter described the STScI Electronic
Information Service (STEIS) in some detail. This service is filling an
increasingly important role in distributing the most up-to-date HST
information to our user community.
   It is possible to access STEIS from the SPAN network. The following
are examples of commands that can be issued (on your own system) to
list the contents of a STEIS file, display the contents of a
directory, or copy a file from STEIS into your own local account.

$ type ZEUS stsci.edu!anonymous name::RREADME
    (outputs the README file to your screen)
$ directory ZEUSstsci.edu!anonymous name::Stsci
    (outputs the contents of the Stsci subdirectory)
$ copy ZEUSRstsci.edu!anonymous name::Stsci/README README.STSCI
    (copies the RREADMES file from the Stsci subdirectory into a file
in your local account)

   If the node ZEUS is not in your SPAN tables, you can use the node
number 6624 in place of the string ZEUS. Note that name in the above
commands should be replaced with your own userid, and should be
preceded by a  blank space.
  Bitnet users can access our information service as well. Princeton
runs a Bitnet FTP Server (BITFTP) that allows users to transfer files
from FTP sites via Bitnet. To get information on BITFTP send a message
containing the one line HELP to BITFTP@PUCC.
  If you have any problems connecting to STEIS, please consult your
local system administrator or network expert, or contact the User
Support Branch (userid USB) at STScI. Comments or suggestions
regarding this service should also be addressed to USB.
 -  Dennis Crabtree and Lauretta Nagel

16.7    HOW TO CONTACT STScI
Telephone: If an individual staff member's extension is not known, a
telephone number for general use is 301-338-4700.
Telex: 6849101-STSCI
Facsimile machine: 301-338-4767
Electronic mail: It is possible to reach most staff members at STScI
by using electronic mail. STScI is connected to SPAN, Bitnet, and the
Internet. Address formats are as follows:

SPAN: SCIVAX::userid
        or 6559::userid
Bitnet: [e-mail]
Internet: [e-mail]

In most, but not all, cases the userid is the staff member's last
name. If you have trouble reaching someone, see if that person's
userid is listed in the Membership Directory published by the American
Astronomical Society. If the staff member is not listed, send the mail
to the User Support Branch (userid USB), and we will forward it.

Mail: Our address is:
Space Telescope Science Institute
3700 San Martin Drive
Baltimore, MD 21218 USA


16.8    THE ST-ECF NEWSLETTER
16.9    NEWSLETTER NOTES
  Comments on the STScI Newsletter should be sent to the editor, Howard
E. Bond (301-338-4718; userid BOND). Any corrections, additions, or
deletions to the mailing list should be sent to Amy Connor in the User
Support Branch (userid CONNOR).
  The Newsletter is produced on an Apple Macintosh computer by Dave
Paradise and Carl Schuetz. Some Macintosh-specific control characters
may be found in this verion of the Newsletter, posted by Peter Reppert.

  The Newsletter is issued 3-4 times a year by the Space Telescope
Science Institute, which is operated by the Association of
Universities for Research in Astronomy, Inc., for the National
Aeronautics and Space Administration.