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: userid@stsci.bitnet Internet: userid@stsci.edu 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.