SPACE 'fEIFSCOPE SOENCE ...______._.INSTITUIE Operated for NASA by AURA November 1991 Vol. 8No. 3
HIGHLIGHTS OF THIS ISSUE: HSTSCIENCE HIGHLIGHTS WF/PC OBSERVATIONS OF THE STELLAR O NEW SCIENCE RESULTS ON M87, CRAB PULSAR CUSP IN M87 O COSTAR PROGRESSING WELL The photograph on the left shows one of a set of images of the central regions of the giant ellipti O ANSWERS TO YOUR QUESTIONS ABOUT HST DATA cal galaxy M87, obtained in June 1991 withHSI's Wide Field and Planetary Camera {WF/PC). 0 CYCLE 2 PEER REVIEW UNDERWAY Analysis of these images has revealed a stellar cusp in the core of M87, consistent with the pres ence of a massive black hole in its nucleus. A combined approach of image deconvolution and modelling has made it possible to investigate the starlight distribution in M87 down to a limiting radius of about 0'.'04 from the nucleus (or about 3 pc from the nucleus if the Virgo cluster is at 16 Mpc). The results show that the central struc ture of M87 can be described by three compo nents: a power-law starlight profile with an r·114 slope which continues unabated into the center, an unresolved central point source, and optical coun terparts of the jet knots identified by VLBI obser vations. In both the V- and /-band Planetary Camera images, the stellar cusp is consistent with the black-hole model proposed for M87 by Young et al. in 1978; in this model, there is a central mas sive object of about 3 x 109 Me. The central luminosity spike remains unre solved with the Planetary Camera, and is at least as blue as the rest of the M87 jet In a paper report ing these results (now in press in The Astronomi cal Journal), the WF/PC Investigation Definition Team (IDT) argues that the central spike is entirely due to nonthermal (synchrotron) radiation. A near-infrared (F785LP) image of the nuclear regions andjet of the giant el The WF/PC images, as well as recent Faint liptical galaxy M87, obtained with HSI' s Planetary Camera. The image has Object Camera (FOC) images, also show M87's been deconvolved with 80 iterations of the Richardson-Lucy algorithm. The well-known jet with unprecedented optical resolu- area shown is 293 by 24.6 arcseconds, and the exposure time was 1400 s. Note especially the compact nature of the central lwninosity spike. The other com pact sources scattered about the image are globular clusters in M87. The un precedented resolution of the HST image makes it possible to determine the Subscribers- distribution of starlight further into the nucleus than has been possible from Don'tforget to renew your subscription. ground-based data. This distribution is consistent with the presence ofa 3-bil A renewal form is on the last page of this issue. lion-solar-mass black hole at the center of M87. Courtesy of the WF!PC In vestigation Definition Team. SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE2
tion. The FOC and WF/PC. data will be dis HSTSclence Hlghllghts cussed at the upcoming American Astro WF/PC, Observations of the Stellar Cusp in M87 ...... 1 nomical Society meeting in Atlanta. HSP Observations of the Crab Pulsar ...... 2 HST Scientific Program Makes Substantial Progress ...... 2 -Tod Lauer The HSTObservatory From the Director's Office ...... 3 HSP OBSERVATIONS OF THE HST's Observing Efficiency ...... 4 CRAB PULSAR COSTAR Progress ...... 6 HST Spacecraft Operational Status ...... 7 In late October, the High Speed Pho HST Gyros ...... 8 tometer (HSP) team obtained photometry Optical Telescope Assembly Collimation ...... 9 of the optical pulsar in the Crab Nebula. These data demonstrate the capabilities Scientific Instruments of HSP to observe short-timescale Wide Field and Planetary Camera ...... 9 Faint Object Camera ...... 11 phenomena free of the effects of atmo Faint Object Spectrograph ...... 11 spheric scintillation. Goddard High Resolution Spectrograph ...... 12 The observations were taken through A Comparison of GHRS and FOS Sensitivities ...... 13 the F400LP filter with image-dissector tube High Speed Photometer ...... 13 3, with a sample time of 10.74 microsec Fine Guidance Sensors ...... 14 onds. A total of 703,244,160 samples was News for HSTObservers and Proposers collected during four intervals of about half Frequently Asked Questions about HST Data and Data Analysis ...... 14 an hour each. Each interval covered about User's Guide to the STScl ...... 15 50,000 rotations of the pulsar. The sample Observation Problem Reports ...... 15 arrival times were adjusted for the motion WF/PC,-Assisted Early Acquisitions ...... 16 Users' Committee Meets ...... 16 of the Earth about the barycenter of the so STAC Meeting ...... 17 lar system using the JPL DE-200 Planetary STEIS Usage Increases Five-Fold ...... 17 Ephemeris, and for the motion of HST How to Obtain Archival Data ...... 18 about the Earth using the SOGS predictive Proprietary Status of HST Calibration Data ...... 18 ephemeris. An additional adjustment, ten An HST User Survey: The Proposal Submission System ...... 18 Publication of HST Research ...... 19 tatively identified as the difference between Published HST Papers ...... 20 the true HSP clock frequency and the manufacturer's specification value, has Proposal News also been made. Cycle 2 Peer Review Underway ...... 19 In the accompanying figure, data cover Approved Director's Discretionary Programs ...... 22 ing one half-hour have been phased onto Software News the known rotational period (33.396206 STSDAS News ...... 22 milliseconds) of the pulsar. The main pulse AURA News and the interpulse are shown with very high AURA Appoints New Vice President ...... 22 S/N. Details of the light curve, such as the Board Member to Serve on Presidential Science Committee ...... 22 luminosity between pulses and the pulse artalyzed Hubble Fellowship Program structure, are being now. Third Selection Cycle Underway ...... 22 The HSP team will make more high First Hubble Symposium ...... 22 speed observations of this object in both broad and narrow wavelength bands in . Institute News the visual and ultraviolet regions of A Digital All-Sky Survey ...... 23 the spectrum. Year of First Light Proceedings Available ...... 24 October Mini-Workshop ...... 24 -Bob Bless & Jeff Percival Workshop on Status of Women in Astronomy ...... 24 Sabbatical & Long-Term Visitors at STScl ...... 24 Recent Staff Changes ...... 24 HSTSCIENTIFIC PROGRAM Recent STScl Preprints ...... 25 MAKES SUBSTANTIAL PROGRESS Graduate Student Research Assistantships ...... 25 ESA Fellowships at STScl ...... 26 The current scientific program of the How to Contact STSc I ...... 26 HSTiscomprisedof347 individual observ- Newsletter Notes ...... 26 SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE3
Crab Pulsar mean light curve: -50000 pe_riods for some programs utilizing the GHRS due to the suspension of GHRS observations. In addition to the scientific program, utilization of the HST Observatory is as signed to the Orbital Verification (OV), Science Verification (SV), and Engineer ing (ENG) and Calibration (CAL) pro 6000 grams. The Science Assessment Tests (SAT) and the Early Release Observations (ERO) were parts of the last category. The OV program is now nearly complete, with only two Fine Guidance Sensor tests re maining to be executed. The SV program ...."' § 4000 has made substantial progress and will end 0 u on November 30, 1991, although a small number of tests will be executed after that date due to scheduling constraints. The Engineering and Calibration program is an ongoing effort that will utilize 10-15% of the observing time. -Larry Petro & Duccio Macchetto THEHSTOBSERVATORY FROM THE DIRECTOR'S OFFICE For the STScl, which operates the sci Phase ence mission of the HST around the clock, Mean optical-band light curve of the pulsar in the Crab Nebula. A half-hour of HSP the summer months are distinguished more data obtained at 10.7 µs time resolution has been folded onto the 0.033-second rota by the steamy Baltimore weather than the tional period of the pulsar. This light curve demonstrates the high SIN possible while peaceful study and spiritual healing longed maintaining high time resolution. Courtesy of the HSP Investigation Definition Team, for by the academician. With an orbiting Principal Investigator R ; C. Bless. spacecraft, the detailed planning and data handling cannot let up. New spacecraft problems must be addressed and ing programs, of which 100 have now been to begin execution during the next observers notified. completed. The present pool consists of two months. This year, the HST proposal cycle also Guaranteed Time Observer (GTO), Cycle 1 The remaining 146 scientific programs peaked in mid-summer, with last-minute General Observer (GO), and Director's consist of 56 programs that utilize the updates and the flurry of incoming propos Discretionary (DD) programs. These pro GHRS and 90 other programs. Implemen als. Those staff astronomers who traveled grams were approved for execution tation and scheduling of the latter group is to the IAU General Assembly, or spent during Cycle 0 (the interval up to under way, but work on the 56 GHRS pro several weeks observing or at workshops, July 1, 1991) or Cycle 1 (July 1, 1991 grams has been suspended pending resolu returned to new challenges and an increas through June 30, 1992), although the actual tion of the operational status of the GHR.S, ing stream of General Observers, science dates of execution have not necessarily or revision of the programs by the observ data, calibrations, and the reviews needed been limited to those intervals. ers to use other scientific instruments. before the next Telescope Allocation Com Among the 100 completed programs Nearly all programs will be completed by mittee meeting this December; in other are 75 GTO, 20 GO, and 5 DD programs. the end of Cycle 1, but due to scheduling words, "routine operations." Of the remaining 24 7 scientific programs, constraints it will be necessary to ~o:nplete Despite its aberrated optics, the HST 61 (31 GTOand30GO)havebegunexecu some after the beginning of Cycle 2. For Observatory is providing the astronomical tion (i.e., some but not all of the proposed example, this will occur for those 7~grams community with unique and exciting high data have been obtained) and an additional that contain observations that must be ex resolution UV, optical, and near-IR images 40 (16 GTO, 20 GO, and 4 DD) are planned ecuted at a particular date, and 1t12v occur and UV spectroscopy. Of the more than SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE4
300 GTO and GO science programs ac spacecraft time. As gratifying as the de WF/PC and HSP, respectively. In addition, cepted for Cycles 0 and 1, we will have mand was the breadth of international inter there is a good chance that the GHRS can completed about one-third by the time this est, indicated by the fact that the Principal be repaired on-orbit during the same mis Newsletter appears. Investigators represent 19 different coun sion. In order to accomplish all these tasks Unfortunately, because of the failure of tries. The nwnber and quality of these pro with some contingency for unforeseen the Goddard High Resolution Spectrograph grams will ensure a high scientific produc needs, the HST Project at Goddard Space (GHR.S) side 1 power-distribution system tivity for HST until the first servicing Flight Center is working with the Johnson in July (see page 12), programs using the mission is able to restore its originally in Space Center to develop a mission with two GHRS have had to be put on hold until the tended performance. astronaut teams to carry out four extrave use of Side 2 can be restored. The calibra As discussed in the previous Newsletter hicular-activity periods. While efforts of tion program for the Fine Guidance Sensors and elaborated below, the planning and de greater magnitude will be required to con is beginning after an extensive collimation velopment required for the first shuttle ser struct the space station in the second half of effort, and some early science observations vicing mission have intensified. With the this decade, the HST servicing mission is will soon be executed. The science team for second gyro failure in June, and the GHRS shaping up to be one of the most ambitious the High Speed Photometer has now essen failure in July (both reported in detail else missions yet attempted. tially completed its calibration program, where in this Newsletter), the menu of de -Peter Stockman thus permitting the initiation of UV photo sired servicing activities has become exten metric and polarirnetric observations. sive. The baseline mission now includes We are pleased by the continuing the installation of new solar arrays as well HSTs OBSERVING EFFICIENCY strong demand for HST observations by the as at least two gyro assemblies (containing The August 1991 issue of the ST-ECF international astronomical community. As two gyros each). Newsletter contained an excellent article on described in more detail on p. 19, we re The installation of the replacement HST observing efficiency by Piero ceived over 480 proposals for Cycle 2 pro Wide Field and Planetary Camera (WF/PC Benvenuti and Benoit Pirenne. This article grams, requesting nearly 12,000 hours of II) and COSTAR will retire the current considered the actual amount of time HST devotes to collecting photons from targets, and plotted the amount of collection or "ex posure" time per instrument for the period Target Acquisition Guide Star Acquisition November 1990 to June 1991. The time that HST does not spend exposing on tar gets may be regarded as the overhead time Exposures required for the conduct of operations with the HST Observatory. Both the ST-ECF analysis and our inde pendent review of six months of operations Earth Occultation (January to July 1991) indicate that the "ex posure time" efficiency is about 9%. Since this differs significantly from the ''time-on S.I. Control target" efficiency of 30-35 % that is our op erational goal (see below), we have broken down the accounting of overhead activities to understand better how the remaining time is being used and where significant improvements may be made. The utilization of the HST Observatory SAA, slews, deadtime may be characterized by six types of serial activities: guide-star acquisition, target ac quisition, exposure, control of the scientific The average breakdown of HST time among spacecraft slews, Earth occultati01 • instruments and spacecraft, Earth occulta spacecraft and instrument overhead, and exposures. An "exposure" efficiency <,_f tion of the target, and other overhead items about 9% is currently being achieved. On average, the "spacecraft-time" or "on-tin - such as pas.sage through the South Atlantic get" efficiency (i.e., the fraction ofthe time that HST spends acquiring targets, setting Anomaly (SAA), slewing of the telescope, up the exposures, and actually exposing) is about 30%. and unscheduled deadtime. SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGES
The typical proportions of time spent instruments, or are required by the fact within the range 25 - 35%, with the lowest on these activities are shown in an accom that we must operate at HSTs low orbital values being due to the spacecraft or a sci panying figure, and are based on the recent altitude. entific instrument being placed in safe months' GO, GTO, and Science Verifica However, we can gauge the capabilities mode. Thus the ground system is already tion programs. As mentioned above, the of the ground system by referring to the surpassing the near-term goals for planning figure shows that scientific exposures ac goals that were established for on-target ef science observations. For Cycle 2, the goal count for an average of 9% of the Observa ficiency based upon pre-launch studies. is 32.5%, and for Cycle 3 it is 35%. Theim tory time. This is the time spent actually in The on-target time is defined as the elapsed provements mentioned above concerning tegrating on targets. The remaining time time between the completion of the slew to the avoidance of SAA passages will prob spent pointing at a target is consumed by a target and the completion of observations ably be sufficient to achieve the Cycle 2 acquiring the guide stars used to control the of that target, excluding target occultations, and 3 goals. Since the planning system will telescope pointing (8%), acquiring the tar SAA passage, and end-of-orbit deadtime. soon be near its ultimate performance level, get itself in the scientific instrument aper In terms illustrated in the first figure, the further efficiency improvements must ture (3%), and configuring the scientific on-target time is computed as the sum of come from possible changes in the opera instrument for use and reading out the sci exposure, S.I. control, guide-star acquisi tion of the scientific instruments and the ence data, usually to the onboard tape re tion, and target acquisition times. The goals actual design of the scientific observations. corder (16%). established were for 20% on-target effi The scientific efficiency of the HST During a typical observation, time is ciency during Cycle 0, and an average of Observatory is affected strongly by the ac also lost to occultation of the target by the 27 .5% efficiency during Cycle 1. tual scientific programs specified by the Earth (typically 45%). The remainder of The efficiency achieved for external observers. For instance, a program contain the Observatory's time (about 19%) is science targets during each week of the past ing many short WF/PC images will have a comprised of time spent during passage of year is shown in the second accompanying small ratio of exposure time to instrument the spacecraft through the SAA (which af figure. The values achieved are typically overhead due to the time required for fects both the guidance system and most of
the instruments), to unschedulable time 40 I (usually short time intervals during which I I I I _L ___ L ___ .l_ __ 35 no short exposures are available to be I I I I scheduled), and time spent slewing to that I I p 30 ------L-- .!. target (at HSTs slew rate of 360 degrees I I I e I I per hour). I I 25 ---L I In the future, it should be possible to e I n I I I I make incremental operational improve 20 --- L __ r _ .1 ___ ...J ___ ...J __ - _ 1__ --L t I I I I I ments in each of the five overhead catego a I I I I I I I ___ LI __ _ I I I I I I I I I I I I I ries. A task force led by the Science and g 15 - - .1 ___ ...J ___ ...J ____ I____ L_ _L __ _ .l_ _ __ _l ___ ..J ___ ...J ____1_ __ -L e I I I I I J I I I I J I I I I I I I I I I I I I I t I Engineering Systems Division at STScI has I I ! I I I I I I 1 I 1 I I __ _ L ___ l. - - .1 ___ ...J - __ ...J ____ I____ L _ _ _ L ___ .!. _ __ _i _ __ ..J _ _ _ ...J ____I _ __ _ L 10 been established to review current HST I I 1 l I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I operations and recommend specific im ___ L ___ .!_ __ _l ___ ...J ___ ...J ______L ___ L ___ .!_ ___ _i ___ ..J _ __ ...J ___ ...J ____ L 5 I I I I I I J I I I I I I provements. For instance, software im I I I I I I I I I I I 1 J I I I I I I I I I I I I I provements are about to be installed in the 0 I I I long-range planning system, which should ~ ~ Ii: a; '!' ~ > u -.h -"'.:.. - ,;.. - "'- Q. Q. ~ ~ ::; - - u "' "' "'c "' "' u 0 .. .s. ... u significantly reduce the amount of time lost 0 .. .. c( .. q z c! :i; :i; 7 c( q .;, .;. ..; :? ,;. j" ... ,;." ... to target occultations and passage through - ...... ~ ~ :'.! ~ ~ .. the SAA. In addition, although we are cur - rently using two-pair guide-star acquisi Weekly mean "on-target" ejficien.:ies achieved for external science targets dzuing the tions for most scientific observations, expe past year. The efficiency is expressed as the percentage ofeach week spent on external rience has shown that single-pair science targets. Time utilized /01 calibration and snapshot survey observations has acquisitions should be sufficient been excludedfrom the sum. The figure shows that, except during a few occurrences of Although several such areas for reduc spacecraft or instrument safing, a1 average ofabout 28% ofthe time has been devoted ing the overhead times have been identi to on-target or "spacecraft" ti. ie. Thus the Cycle 1 goal of 27.5% has already fied, it is difficult to forecast the ultimate been met. HST science efficiency in terms of expo sure time. Many of the overheads are "built in" by the design of the current scientific SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE6
optics, is expected to remove the effects of the HST primary mirror's spherical aberra tion and restore the originally designed per formance of the scientific instruments. Development of COSTAR has pro ceeded well since program inception in January 1991. The conceptual definition phase was completed on schedule in Febru ary 1991, and the Preliminary Design Re view (PDR) was completed as scheduled in early May. The next major milestone is the Critical Design Review, scheduled for early December 1991. The Quarterly COSTAR Review held in late August at A-Fitting Ball Aerospace Corp. showed the program to be on schedule for this December re view. (Further details of this review are given below.) Future critical milestones to support the December 1993 launchofthefirstHSTser vicing mission include completion of fabri Schematic diagram ofCOSTAR. This instrument will be installed into HST during the cation and assembly in September 1992, first servicing mission in place of the High Speed Photometer. It will deploy correct followed by test and verification through ing optics in front of the FOC, FOS, and GHRS. May 1993. Delivery of the instrument to the Goddard Space Flight Center (GSFC) preflashes, shutter control, and data vations. In addition, optimizing the opera will occur the following month. The inter readout tion of the spacecraft and the scientific in val between delivery and launch is reserved Therefore, it is on-target or "spacecraft" struments may realize a similar improve for testing at GSFC, and launch prepara time, rather than exposure time, that has ment Finally, the results of the study now tions at the Kennedy Space Center. been allocated to observers, in order to al underway by the STScl Efficiency Task The PDR was a critical juncture for low them to optimize the exposure time ob Force will be useful in improving the accu COSTAR. The review was held at GSFC tained within their spacecraft-time alloca racy of the RPSS Resource Estimator and with over one hundred people in atten tions. To calculate the spacecraft time in helping observers optimize their science dance. The outcome was that the technical required for a program, observers have observations. review committee found that, although been provided with the Resource Estimator COSTAR would be challenging, they saw -Larry Petro, Peter Stockman, & Brad as a part of the Remote Proposal Submis Whitmore no technical "showstoppers." While some sion System. The version of this estimator details have changed since the PDR, the provided for Cycle 1 was written well be fundamental design (see figure) has re fore the launch of HST and therefore before COSTAR PROGRESS mained unchanged since inception. any experience had been obtained in sched As described in previous Newsletters, a The STScl COSTAR project was con uling the science program. After-the-fact strategy for recovering HSTs scientific ca cerned with the relatively small clearance accounting has shown that the consumed pabilities has been developed. This strategy between the FOS beams and the multi Spacecraft Time is approximately 1.3 times calls for replacing the High Speed Photo layer insulation (MLI) blankets that are in the value computed with the present Re meter with COSTAR (the Corrective Op stalled at the interfaces between the four source Estimator. Revisions to the Re tics Space Telescope Axial Replacement), axial Scientific Instruments. An optical re source Estimator are in process with the an instrument that will deploy corrective design that increases the nominal clearance goal of matching after-the-fact accounting elements into the optical paths in front of to greater than 28 mm at all points has alle within 5% on average. the Faint Object Camera, Faint ~jec.t viated concerns about possible vignetting In summary, the goal for Cycle 2 is to Spectrograph, and Goddard High Resolu by bulging or displaced MLI. improve the on-target efficiency by more tion Spectrograph. Installation of The COSTAR optical design has now than 5 percentage points. This will increase COSTAR, along with replacement of .he matured, and the mirrors are on order from both the amount of time available for ob Wide Field and Planetary Camera by a new two vendors, Tinsley and UTOS, each of serving and the number of executed obser- camera (WF/PC. II) with built-in corrective which will produce a full set of flight op- SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE7
tics. The first pieces are due for delivery in Another level of verification will come mers and engineers at STScI are working December 1991 and all the mirrors should from the Independent Verification Team, with NASA and Ball engineers on the fail be on hand in March 1992. The specifica set up by the HST Project at Goddard to ure analysis, on-orbit engineering tests, and tions for figure and surface roughness are check independently the optical prescrip development of work-arounds and side exacting, to assure that the throughput and tions and alignments and verify the test re switch procedures. For further details of image-quality goals will be met, but are sults. They will also perform their own tests this failure, see Ron Gilliland's article be within the demonstrated capabilities of of the RAS and COSTAR+RAS wavefront low (p. 12). both manufacturers. A problem with the errors using a wavefront analyzer. These A number of operational improvements sizing of the FOS M2 mirrors was encoun independent verifications of the critical as have been made since June. Several im tered in September, but was rapidly cir pects of the design will ensure that the type provements have been made in the use of cwnvented with an inventive adaptation of of error that led to the spherical aberration the Fixed Head Star Trackers, resulting in a the mounting scheme that has been under in the HST primary will not recur with reduction of the failure rate of position up development COSTAR. dates after slews to essentially zero. This in Topics discussed in detail at the August For readers who are interested in fur turn has removed the biggest source of Quarterly Review included system design ther details, the high-level specifications failed guide-star acquisitions. In fact, all of and performance, the end-to-end wavefront for COSTAR follow. Two specifications the guide-star acquisitions in the last two budget, the optics, the design of the refrac control image sharpness. The first is the months have been successful. tive beam simulator (RAS) that will be Strehl ratio, which is the ratio of the peak The planning system at STScl has been used to test COSTAR, the Hubble Optical intensity in the observed image to the peak modified to schedule interleaved WF/PC. Mechanical Simulator that will hold intensity in the image from a perfect tele Earth flat fields properly. Starting in July, COSTAR and the test components, and the scope. The second is the encircled energy. we have been taking many Earth flats in plan for aligning and testing COSTAR. The The Strehl ratio specification is that the cor support of the WF/PC. calibration program, project has reached the point that the de rected image quality for the FOC f/96 chan as described_in more detail below (p. 9). tailed designs and analyses of the nel shall give a minimum ratio of 0.55 at We are in the last stages of testing modifi deployable optical bench, the mechanisms, 6328 A, with a design goal ofO.(i(). Had the cations to the planning system that will al and the optics can be compared to the error HST primary been within specifications, low us to obtain parallel observations (i.e., budget. This comparison shows that the Strehl ratio would have been approxi simultaneous observations with two of the COSTAR can be built to stringent system mately 0.8. The encircled-energy specifica scientific instruments). The first on-orbit level specifications. Finally, Ball Aero tions are that 60% of the light must be test of parallel observations is expected in space Corp. showed enough detailed plan within a 0 '.' 1 radius at the center of the FOC early January 1992. ning at the Quarterly Review to convince and FOS fields, and within a O'.' 125 radius While it had essentially no effect on on the HST Project and STScI that COSTAR at the center of the GHRS field. Scattering going scientific observations, there was can be aligned and tested within the time from the surfaces of the COSTAR mirrors another gyro failure (this time of gyro #4) allotted in the schedule. in the UV is controlled by the specification this past swnmer. This gyro behaved inter To ensure that COSTAR will work, that therms surface roughness of the mir mittently for several weeks, and then appar there will be extensive testing using inde rors for all spatial scales less than 1 mm ently failed completely. At the time of the pendent measurements and analyses by must be less than 10 Arms. Finally, the op initial failure, HST was operating in its nor four groups. The European Space Agency tical throughput of each pair of correcting mal four-gyro configuration. The failure (ESA) will provide a Structural and Ther mirrors must be no less than 56% at 1216 A resulted in a saturated output from the gyro, mal Model (STM) of the Faint Object Cam and 72% at6328 A. e.g., it indicated the maximwn possible ro era that exactly duplicates the optics of the tation rate. The flight software recognized -Jim Crocker, Holland Ford, George in-flight FOC, although replacing the pho Hartig, & Robert Jedrzejewski the erroneous input immediately and took ton-counting detectors with CCDs. This the gyro out of the control loop, falling will be tested in Europe with an aberrated back to a three-gyro configuration. The HSTSPACECRAFT OPERATIONAL beam simulator to verify that COSTAR saturated condition lasted for about 80 sec STATUS corrects it exactly. The images will be ana onds, after which the gyro output returned lyzed by Ball, STScl, and ESA. The goal Of the changes in HSTs operational to nonnal although the flight software re will be to check that COSTAR, when status that have occurred since the last issue mained in the three-gyro configuration. aligned properly, can deliver the perfor of the Newsletter, the one with the greatest After investigation, we returned gyro mance outlined in the Level I specification impact is the failure of a low-voltage power #4 to the control loop. A very similar event for HST, and to investigate how the images supply in the GHRS. This failure prevents occurred again three days later, except that can be used to align the instrument when use of side 1 altogether, and allows 1Jnly in the gyro stayed saturated for 10 minutes. deployed on-orbit tennittent readouts from side 2. Astrono- SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGES
HST GYROS /0 Since its launch on April 24, 1990, HST , OUTPUT has experienced failures of two of its six (GIMBAl ROTATION gyros, the mechanisms used to point and , AXIS) SANNING DISK I stabilize the telescope (see previous ar (ROTOR) ticle). Because there are only four gyros left, and the telescope needs at least three to operate, it is natural to ask what the gyros are and how they work. The principle of the gyros is similar to that of a child's toy gyroscope: the inertia of a spinning mass provides a restoring "'6. force that counters any displacement of its "-.....5 spin axis. In the HST case, the gyros have only one degree of freedom-the spin axis / SPINAXIS is supported by only one gimbal. In the ac companying diagram, rotation about the in • I FRAME put axis causes the gimbal to precess about (OACASE) ct> INPUT AXIS the output axis. (You can see why this hap pens if you remember that the angular-mo menturn vector is parallel to the spin axis.) • What our engineers call a "gyro" is ac The single-degree-of-freedom gyros HST. Rotation about the output axis is detected tually composed of some very sophisti by sensors, creating a feedback control system. cated electronics, which together with the above hardware form a feedback system Finally, a week later, the gyro failed with a the same in the three-gyro configuration as that works in concert with the Fine Guid saturated output and remained saturated. in the four-gyro configuration. ance Sensors and Fixed Head Star Trackers Analysis indicates that the likely cause These events led to a review of the to point the telescope. These electronic of the failure was a failed wire bond in one flight software "sanity" checks that are "reference" gyros are called Rate Gyro As of the hybrid circuits in the gyro electronics available when operating in three-gyro semblies. They are made up of a Rate Sens package. Although in a different circuit, it mode and possible failure modes. As a re ing Unit and an Electronic Control Unit, is a similar failure to the gyro #6 failure that sult, modifications are being made to the both of which can be replaced in orbit. occurred last December. flight software that will provide more ro There are three of these RGAs, each con Gyro #4 was left running, although its bust checks of gyro performance while in taining two gyros (x- and y-axes) whose in output obviously was not used to control three-gyro mode. A zero-gyro safemode put axes are skewed with respect to the the telescope. In late October, it unsaturated that is designed to maintain the health telescope's axes. This offset means that again, and produced reasonable data for a of the spacecraft has also been added, three-dimensional control of the spacecraft period of about a week. The HST Opera but (obviously) it cannot carry out a can be maintained with any configuration tions Control Center at GSFC is continuing science program. of three or four gyros. That is, if the six gy to monitor its performance. In addition to the gyro #4 failure, there ros were aligne.d exactly with the telescope Following the failure of gyro #4, we have been two other gyro anomalies since axes, and two on the same axis malfunc turned on the last spare gyro, gyro # 1, and the last Newsletter. Gyro #5 has shown an tioned, then only the two remaining axes after calibration it was placed into the con increase in operating current, but there has could be controlle.d. trol loop, returning HSTto a four-gyro con been no change in its performance. Gyro# 1 The gyros are located on the equipment figuration. The four-gyro configuration al has had one short episode of increased shelf near the back of the telescope, in order lows the flight software to perform checks noise. These anomalies are distinct from to isolate them from vibrations caused by on gyro data and detect failures, as it had those exhibited by gyros #4 and #6 as they the reaction wheels and the high-gain an done with gyro #4. Science operations are were failing. Both situations are being ana tenna. The reaction wheels are four fly also possible with only three gyros, as in lyzed, but at this time they are not believed wheels, each with mass of about 45 kg, deed was done for a period this summer to be precursors of further failures. which control and modify spacecraft atti while the problems were being diagnosed. -Rodger Doxsey tude based on RGA information processed Vehicle pointing performance is essentially and interpreted by the Control Law Soft- SPACE TELESCOPE SCIENCE INSTITUTE NEWSLETTER NOVEMBER 1991 PAGE9
ware. The reaction wheels are also propose additional observations as neces lions taken since then will be applicable mounted with angled spin axes to provide sary to improve the collimation. to almost all data taken since then (although redundancy. These observations consisted of a series there may be some differences in focus There is a separate set of backup gyros of images at different coma seuings to es setting). The OTA has almost stopped called the Retrieval Mode Gyro Assembly, tablish a more accurate zero-coma setting shrinking, and the secondary will now which are used if fewer than three main gy taken both in the FOC and the WF/PC. The be maintained within 5 microns of its ros are available. There is no direct ground secondary was then placed temporarily at present position. communication with the RMGA-it is en this position, and a series of four pairs of -Chris Burrows abled by the Power Distribution Unit The images were taken with the FOC to fix the telescope is then safely kept in "hardware astigmatism. Finally a focus sweep was run sun point" mode with the aperture door in both cameras to see if the focus setting SCIENTIFIC INSTRUMENTS closed, but of course it cannot then be used is optimal. for scientific observations. The conclusion of all of these experi WIDE FIELD AND PLANETARY CAMERA -Pete Reppert ments was that the day 323 position, modi fied only by the present desorption correc 1. WF!PC safing and thermal-anomaly his tions, is optimal in astigmatism and focus tory. The calibration of the Wide Field and OPTICAL TELESCOPE ASSEMBLY but could be improved in coma. However, Planetary Camera (WFIPC) is adversely af COLLIMATION the effect of this improvement on the cam fected by transient changes in its thermal The present secondary-mirror position era images is slight and was not felt to be of state. Such changes have resulted from in the telescope was first set on day 323 in any scientific value. HST safing events, internal power cutoffs, 1990. The secondary was positioned in Similarly the throughput of the spectro and decontamination procedures. Nearly decenter and tilt to remove coma in the WF/ graphs was not expected to be affected. A all of the calibration changes are the conse PC and FOC (approximately), and to "five points of light" test was then run at the quence of the removal of a part of the UV remove astigmatism as measured by the zero-coma position to assess the three flood charging while the CCD detectors are Optics Control System (wavefront sen FGSs; neither the astrometry nor the guid at an elevated temperature. sors). Since then, with very few exceptions, ing was improved significantly. The re In-flight experience has shown that the secondary has been maintained at sidual amount of coma involved (about 1/ raising the CCD cold junctions above ap this position with occasional adjustments 15 wave) is not felt to be a problem for the proximately -40 C results in the formation to preserve the focus setting, as the graph next-generation instruments, although the of a visible light contamination (known as ite-epoxy metering truss shrinks due to wa telescope may be recollimated just before "the measles"), which seriously degrades ter desorption. the servicing mission. image quality. Since the equilibrium tem One attempt, on day 66 in 1991, was In conclusion, the telescope collimation perature of the cold junctions is about -35 C made to arrive at a better selling, and it led is now better understood, and although when the thermo-electric coolers are pow to better FGS performance. Unfortunately marginal improvements are possible it was ered off, the WF/PC must be "decontami the camera images were too comatic, so the felt that they did not compensate for the in nated" following every such power-off epi secondary was reset to the day 323f)O posi creased spacecraft time that wculd be sode. This is accomplished by warming the tion. The Science Working Group then needed to repeat some calibrations. The CCDs so that the cold junctions reach be asked Dan Schroeder to convene an optical secondary mirror will therefore be left in tween -2 and +IO C for more than 1 hour. alignment panel to review all the data, and the day 323f)O position, and PSF observa- This causes some loss of UV-flood and,
WF/PC SAFING AND THERMAL-ANOMALY HISTORY Date Day Number Remarks 1990 Dec 31 365 Telescope Safes - FGE 3 bit flip 1991Jan2 002 Mini-Low-Temp Decontamination - Inertial-Hold Safemode Recovery 1991Jan26 026 De-Ice Decontamination (-82 C) - Failed to remove daisies 1991Jan28 028 Mini-Low Temp (-20 C) - Removed daisies; created measles 1991Jan29 029 Low Temp (-15 C) - Removed measles 1991May2 122 PSEA Hardware Safe Mode (CCDs at-35 C for 80 hours) - Measles 1991May8 128 Hot-Junction Decontamination (+12 C) - Removed measles 1991 Jul 3 184 WIDLE turned WFC TEC off for 7 hours (WFC reached -25 C) - Measles on WFC CCDs 1991 Jul 5 186 Flash Decontamination (+6 C) - Removed measles SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE 10
therefore, a calibration change in both pho At the start of April 1991, the following To determine which type of flat field tometric zero point and flat-field structure, preliminary Planetary Camera flats were has been used on an existing processed since the UV flood increases the quantum delivered by the WF/PC IDT to the STScl dataset, one should examine the keyword efficiencies of the CCD detectors in a loca and placed in the calibration data base: FLATFILE in the science image header. tion-dependent manner. F230\V,F284\V,F336\V,F439\V,F555\V, This gives the flat-field reference file name Since the first on-orbit UV-flood of the F702\V, F785LP, and F889N. in the format: wref$
4. Interrupted Exposures. WFfPC_ expo describes the processing in more detail and data reduction, and then summed to yield sures longer than 300 s may be interrupted the motivations for the changes. 1bis docu the final corrected spectrum. if the FG Ss lose lock on guide stars. In such ment can be obtained from Nancy Fulton at A new version of CALFOS that sup cases the WFIPC- shutter will be closed un STScl (410-338-4955, useridFULTON). ports these operations has been submitted and will be the standard for pipeline pro til lock is established again. The missing -Perry Greenfield & William Sparks exposure time is not currently reflected in cessing by the time this Newsletter appears. the keyword EXPTIME in the science im In the long term, an operational "real-time" age (.dOh) file headers. This has been fixed FAINT OBJECT SPECTROGRAPH fix will simply dither the deflection coils by in the next release of the ground-system The Faint Object Spectrograph (FOS) the appropriate amount to remove the ef software, scheduled for implementation in is working well, with a combination of Sci fects of GIM during an observation. This late October 1991. ence Verification (SV), General Observer fix will be included in a future operations If loss of lock was reported during an (GO), and Guaranteed Time Observer software update, currently scheduled for observation, the Standard Header Packet (GTO) observations being scheduled and February 1992. (.shh) file provided with the data should be executed regularly. The programs that are Various target-acquisition modes have examined.The keywords WFOCTMO 1, 02, part of SY are designed to verify and cali now been thoroughly tested. A bug in the 03, ... , 15 contain the shutter movement his brate the basic modes of the FOS, allowing way the scheduling program handled tory. If WFOCTM02 is nonzero, then the observers to acquire and analyze their sci proper motions was revealed the hard way exposure was probably interrupted (the entific data properly. These programs have when a target acquisition failed for a long trailer file should also be read). The actual included the measurement of instrumental observation. Improved aperture positions exposure time may be determined by sub characteristics such as dark counts, scat and aperture-to-FGS alignments have re tracting the lost time as recorded by the tered light, flat-field behavior, aperture po duced the need for "big" peak-ups (i.e., a 6 WFOCTMxx keywords (which is in units sitions, wavelength scales, and photometric by 2 pattern with the 4'.'3 acquisition aper of 0.125 seconds mod 216) from the com and polarimetric perfonnance and stability. ture) and targets are usually found within manded exposure time. In addition, the operational characteristics the initial 4 '.' 3 aperture position. BINARY SEARCH works well, although targets can -John MacKenty of the instrument are being determined, in cluding background rates at various galac still be left off center by as much as three tic and ecliptic latitudes, and wavelength pixels (0'.'24) with this acquisition mode, FAINT OBJECT CAMERA offsets between the internal calibration depending on the brightness of the target The importance of UV imaging as a lamps and external sources. Target-acquisi star and the effects of GIM and jitter during unique capability of HST is now clear, and tion methods and techniques are being es the acquisition. The user community so it is reassuring that the UV response of tablished and are discussed further below. should be aware of the importance of set the FOC has been measured (and moni SV is progressing well, with approxi ting proper BRIGHT and FAINT limits in tored) since launch and shown to be close mately 90% of the necessary data in hand order to have successful results with BI to the expected values as given in the FOC and undergoing analysis by FOS NARY SEARCH acquisitions. Instrument Handbook. IDT members. Photometric stability ap WFfPC_-assisted target acquisition has Near the end of November 1991, the pears to be good, including in the far been tested on the blue side of FOS and has calibration pipeline will be changed to im ultraviolet. Time-resolved mode and worked well, placing a target star within prove the calibration of FOC science data. spectropolarimetry mode have both been 0'.'25 of the desired location in the 4'.'3 ac For imaging modes, the flat-field correc used successfully for GO proposals. quisition aperture. tion had been applied before the geometric In addition to the SV program that was The instrument has gone into safe mode correction. After the change the order will defined before launch, the discovery of twice due to relatively minor technical be reversed; the geometric correction will geomagnetically induced motion (GIM) of problems that have now been resolved. In be applied before the flat- field correction. the spectrum on the detectors (especially on mid-July, a test star slightly exceeded the Previously the data products of the the red side) created the need for a program "overlight" limit, which had been set con pipeline for imaging mode had been: (a) a to characterize this phenomenon. (See the servatively low, and safcd the instrument raw image, (b) a photometrically corrected article on the FOS in the March 1991 STScl The value of this limit has been increased image, and (c) a photometrically and geo Newsletter for more information.) Testing by 50% to prevent unnecessary future oc metrically corrected image. The data prod has shown this effect to be highly repeat currences. At the end of July, a BINARY ucts will be changed so that now there will able and readily modelJed. The operational SEARCH target acquisition failed due to a be: (a) a raw image, (b) a geometrically cor fix in the near term is to break long int.cgra combination of circumstances (GIM, rected image, and (c) a geometrically and tions into exposures of two minutes each. spacecraft jitter, and the star's initial posi photometrically corrected image. The These separate integrations can then be tion for the search). This should not nor STSd InstrumenJ Science Report FOC-051 shifted by the appropriat.c amount during mally safe the instrument, but the particular SPACE TELESCOPE SCIENCE INSTITUTE NEWSLE1TER NOVEMBER 1991 PAGE12
circumstances caused the FOS to attempt G140M (the prime far-UV capability), has On August 5, 1991, however, the execution of a vestigial program branch in become unavailable for scientific use, and GHRS again had a loss of the SDF inter the operations software, and the instrument is expected to remain so unless an on-orbit face. This time, the SDF interface did not safed. This problem has also been ad repair of side 1 can be performed during the return to normal operations after a reset, dressed and should not recur. It was during first HST servicing mission. suggesting a continuing problem. Normal this "safed" period in July that the instru 2. Side 2 data are currently routed through a full telemetry is returned from either side of ment was officially handed over from the science data formatter (SDF) powered from the GHRS only when the low voltage is IDT to STScI. the side 1 electronics; thus usage of side 2 fully up for science operations, which is not The special HST spectroscopy issue of has become unreliable, in addition to side 1 the case for side 1 when it is only serving as Ap. J. Letters in August 1991 contains four having failed altogether. a conduit for side 2 data. The August 5 ob articles by the FOS team, reporting obser 3. A solution that would restore reliable us servation used side 2. After the SDF prob vations of the quasars 3C 273 and UM 675, age of side 2 would require switching com lem continued for several hours, a decision and the active galaxies NGC 1068 and munications for all of the scientific instru was made to enable low voltage on side 1 to NGC 1566. These papers contain consider ments, including GHRS, to the spare side capture a telemetry profile of voltage and able details on instrument performance that (side B) of the HST electronics. (Side B is a current distribution. This was done and re should be of interest to potential FOS users. redundant spare that duplicates the cur sulted in (a) a good set of telemetry that has In addition to some early ERO and SAT rently used Side A of the spacecraft elec allowed a secure diagnosis of the failure observations, the remaining FOS GTO ob tronics.) Sides 1 and 2 of the GHRS SDF point, and (b) confirmation that many volt servations are in full swing. While some interfaces are hard-wired to sides A and B ages were detected as out of range by the spectroscopy on QSOs and stellar objects of the spacecraft, respectively, requiring instrument monitoring system, resulting in has been done, much of the early GTO data routing of communications from side 2 a safing of the GHRS. have been in the form of "early-acquisi through side 1 when side A of the space Engineering analysis of the August 5 tion" images with either the PC or WFC. craft is in use. telemetry showed that the voltage distribu These images were intended mainly to set Itshould be noted that this new problem tion throughout the instrument could be ex up future FOS spectroscopy, but many of is not related to the earlier intermittent fail plained in a unique way via failure of a spe the images are interesting in their own ure of the side 1 carousel control (reported cific solder joint in the low-voltage right Considerable effort has gone into the in the June 1991 STScI Newsleuer), which power-distribution system. Analysis (and proper reduction and analysis of these data. can be worked around effectively. The his ground-testing experience) also showed The issue of "accurate astrometry" has be tory and technical details of these failures, that an unbalanced power distribution, as come a major concern as we try to prepare and current testing aimed at understanding sometimes exists on side 1 now, can lead to for the main body of our FOS spectroscopy the precise constraints on continued use of hard failures of other components. There program. Getting a 07 3 aperture onto a the GHRS, are discussed below. fore full low-voltage operation of side 1 has given knot in an active galaxy nucleus During a routine science observation on not been attempted since August 5, and is through a blind offset, for instance, is a July 24, 1991, the GHRS experienced its not likely to be attempted again in non-trivial matter with HST. first loss of SDF interface control. The the future. GOs should be wary of such problems transfer of commands to the GHRS and re In the mode where side 1 operates only and be prepared with their own CCD im turn of data from the GHRS to the HST as a data conduit to side A of the spacecraft, ages or other astrometric data for compli computer is routed through the SDF. Any the standby power-distribution system sup cated acquisitions. transfer of information requires "hand plies proper voltages to all required ele -William P. Blair shakes" between the instrument and space ments. This includes instrument heaters, craft sides; if such an acknowledgement is which have now been off-loaded to side 2. not received, then the SDF interface shuts By this off-loading it was hoped that GODDARD HIGH RESOLUTION down until a reset command is encoun smaller currents across a (possibly) high SPECTROGRAPH tered. The glitch on July 24 was associated resistance solder joint failure might allow In July 1991 the Goddard High Resolu with a fluctuating current on the side 1 maintenance of sufficient voltage at the tion Spectrograph (GHRS) suffered a ma emission-line comparison lamp. It was sus SDF for its continued operation. This has jor component failure, which will have a pected at that time that a problem with the not turned out to be the case with any de significant impact on users of the spectro lamp could have induced a voltage glitch in gree of reliability. Continued operations graph. The failure occurred in the low-volt side 1, leading to failure of the SDF inter have shown only a 50% rate of success in age power supply on side 1 of the GHRS. It face handshake. After an automatic reset, recovering side 2 data without the SDF in will have the following implications: the interface worked without problems for terface being lost 1. Side 1 of the GHRS, which carries out the next ten days. An engineering test has been designed observations with G 140L, Ech-A, and that will allow near-continuous testing of SPACE TELESCOPE SCIENCE INSTITUTE NEWSLE1TER NOVEMBER 1991 PAGE 13
the SDF interface once every 5 minutes. comparison of GHRS and FOS photomet Throughputs for the various FOS aper The purpose of this test (scheduled for late ric sensitivities for point sources well cen tures at 1500 A, as determined from direct October) is to determine if certain opera tered in the aperture. comparison on a point source, are tional conditions (e.g., electronics tempera The sensitivities in cols. 2, 3, and 4 are as follows: 1 1 1 2 ture) may be correlated reliably with the expressed in counts s· diode- (erg s- cm· Aperture Throughput A-1y1. times when the SDF interface can be kept (arcsec) up. If such a robust correlation can be For the GHRS with the Gl40L grating, 4.3 x 1.4 49% found, it might be exploited to restore reli column 2 gives the sensitivity with the 2'.'0 1.0 27% able use of GHRS side 2. square Large Science Aperture (LSA). For 0.5 20% If a reliable correlation that will allow observations with the Small Science Aper 0.3 13% continued, predictable use of GHRS side 2 ture (SSA), the GHRS sensitivity should be 0.25 x2.0 20% cannot be found, then only three options multiplied by the ratio in the final column. remain: With Gl40L the diode spacing is 0.572 A, The GHRS to FOS ratios derived from 1. Use the GHRS side 2 only for projects and the resolutions of the SSA and LSA are the table should typically be within 20% of where very high priority for scientific re 1.1and2.0 diodes, respectively. truth, allowing for good exposure-time turn has been established that favorably The FOS sensitivities are also on a per planning. balances the decreased probability of suc diode basis, for the 1:·0 - diameter circular ~on Gilliland & George Hartig cess. This would be the desired solution for aperture. The diode spacings are 1.0 A and conducting further GHRS science in the 1.46 Afor the G 130H and G 190H gratings, HIGH SPEED PHOTOMETER near future only if more positive options are respectively, and the resolution of the 1'.'0 not deemed possible. Under this scenario, aperture is 1.4 diodes. As a consequence of the vastly im time allocations would need to be balanced A sample calculation: at 1200 A, one proved performance of the HSI' pointing against the realized probabilities of any ob would infer from the above that GHRS control system and a long series of High servation succeeding. G 140L was a factor of 5 faster than FOS on Speed Photometer (HSP) tests, it is now 2. Switch all of the scientific instruments to a per-diode basis. On a per-Angstrom ba possible to center a star in most of the side B of the spacecraft The decision to do sis, the ratio at 1200 A is 8.9. But the FOS HSP science apertures to within a few this will have to be considered in light of does have greater wavelength coverage, hundredths of an arcsecond. This has en the risk this would entail for other compo and starts gaining ground rapidly with in abled much of the HSP SV program to be nents of the HSI' system. creasing wavelength in terms of relative carried out. The instrument continues to 3. Repair G HRS during the 1993 servicing sensitivity. perform well. mission. At this early stage of planning it appears that an astronaut could carry out a fix by: (a) opening the appropriate access COMPARISON OF GHRS AND FOS SENSITIVITIES hatch on the HSI', (b) removing some 70 (!) screws holding a GHRS access panel in Wavelength GHRS FOS/BL FOS/BL GHRS place, (c) either installing a spare low-volt (A) G140L G130H Gl90H SSAILSA age power supply, or simply wiring a by 1100 1.81El 1 O.OOEOO - 0.19 pass to the failed electronics line, and (d) 1150 2.90El2 2.79El 1 - 0.20 closing up the original (or a newly de 1200 7.75El2 1.53El2 - 0.21 signed) access panel and closing the hatch. 1250 1.28El3 3.47El2 - 0.22 It is believed that such a repair would re 1300 1.45El3 4.57El2 - 0.22 store the full capabilities of both sides of 1350 1.53El3 5.70El2 - 0.23 theGHRS. 1400 1.45El3 6.50El2 - 0.23 1450 l.18El3 7.90El2 - 0.24 ~on Gilliland 1500 9.24El2 9.41El2 - 0.24 1550 7.35El2 l.16El3 - 0.25 A COMPARISON OF GHRS AND 1600 5.27El2 1.37El3 1.83El3 0.25 FOS SENSITIVITIES 1650 4.61El2 - 2.19El3 0.26 To facilitate changes that may be neces 1700 3.79El2 - 2.50El3 0.26 sary for Cycle 1 proposals that currently 1750 2.41El2 - 2.89El3 0.27 use the GHRS side 1 low-resolution grat 1800 1.25El2 - 3.45El3 0.27 ing, G 140L, but will be changed to the 1850 4.39El2 - 3.90El3 0.28 FOS, the following table provides a direct 1900 l.29El 1 - 4.50El3 0.28 SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER :r-roVEMBER 1991 PAGE 14
One of the more interesting tests per FINE GUIDANCE SENSORS the other five instruments), (b) code to pro fonned recently was a 5.5-hour continuous cess TRANS-mode observational data, and The SY phase of operations for the Fine observation of the ninth-magnitude rapidly (c) code to process POS-mode observ~ Guidance Sensors (FGS) has begun. SY oscillating Ap star HD 60435, taken tional data. The latter includes all the basic and some parts of the Orbital Verification through the F240W filter on image-~ astrometric corrections and therefore has (OV) activities have been delayed owing to tor tube 3 with a sample time of 82 msec. In pieces that will be used by TRANS-mode the continuing effort to find the optimum addition to the intrinsic variability of the observers too. A scientific description of placement for the HST secondary mirror. star, the data show three anomalous fea the code will appear in the forthcoming ver Even so, both the Early Release Observa tures, none of which is understood fully as sion of the FGS Instrument Handbook. At tions (ERO) and the Science Assessment yet: (a) a sinusoidal modulation with the the moment the code is being reconfigured Tests (SAT) have been completed and the orbital period of HST and a semi-amplitude to reside in the IRAF format. After that data reduced. The fonner are in press (AJ, of 0.9%; (b) a monotonic increase in the there is one more stage of software configu 1992), and the latter have already appeared signal of about 1 % over the interval of olr ration to go through before it becomes (ApJ, 377, Ll7, 1991). servation; and (c) several data dropouts available to GOs in STSDAS. These activities have been carried out lasting a few seconds each. mainly by the University of Texas Space -Mario G. Lauanzi and Larry Taff Many parameters vary with the HST's Telescope Astrometry Team, but STScl's orbital period, and it is not clear which is re FGS Instrument Team has been busy too. sponsible for the observed modulation of NEWS FOR HSTOBSERV The Instrument Scientist Cycle 1 calibra the star's brightness. Since the star itself tion plan was finalized, the Version 1.0 ERS AND PROPOSERS should have become slightly fainter during astrometric data-processing pipeline has the observation period (its brightness is been completed (see below for a brief de FREQUENTLY ASKED QUESTIONS known to be modulated on the rotational scription), a new FGS Instrument Hand ABOUT HST DATA AND DATA period of the star), it should not have book-which will include examples of ANALYSIS caused the slow increase that was seen. The completed proposal forms-is being writ data dropouts are likely a result of space We are moving into an era where in ten, the Cycle 2 Instrument Scientist cali craft jitter, since they occur most strongly at creasing numbers of General Observers bration program is in the design phase (the the night-to-day transitions. Apart from (GOs) are receiving HST data and/or com details depend on the SY and Cycle 1 olr these effects, the noise in the data is due ing to STScl to analyze their data. Here are servations), and we are starting to tackle the nearly entirely to photon statistics. A Fou some answers to a few of the most common problem of jitter elimination using the 32 rier transfonn of the data shows a 1.9 mmag questions that are asked by GOs, Archival kilobit telemetry acquired on the Guide peak, well above the noise of about 0.5 Researchers, and other persons interested Stars. We also are supporting the re-reduc mmag, with a period of 11.7 minutes. This in HST data. tion of the Guide Star Catalog (Version is known to be one of the oscillatory modes The text below is taken from a much 1.2), using new methods developed at of the star. longer article, which has been posted to STScl. In addition, we are continuing to The first GTO program using the HSP observer/frequently_asked_questions on transfonn one of the engineering-only FGS has recently been completed, namely the STEIS. The full version contains consider modes into a GO mode because we expect observation of the luminous blue variable ably more detailed information about the it to minimize the deleterious effects of the P Cygni. This was done as part of a P Cyg questions raised below and numerous other spacecraft jiuer. Finally, we are anticipat campaign that occurred during September topics, and all observers should consult it ing the data from the Fine Lock test that 1991. Another GTO program, the occulta 1. What happens to the science data was designed to demonstrate that most of tion of a star by Saturn's rings, will soon be once an observation is made? The science the loss of sensitivity induced by the pri perfonned, as well as an SY observation of data are separated from the engineering mary mirror figure can be regained by bet the Crab pulsar (see article on p. 2). The SY data, and passed through Routine Science ter control of the Fine Guidance Electrcnics tests remaining to be completed are the Data Processing (the RSDP "pipeline"), inside the FGS. calibration of the POL detector and the de where they are calibrated. They are then The scientific FORTRAN code for the termination of the best entrance-aperture written into the archive and a copy is sent to astrometry pipeline has been completed. It position for the PRISM mode on image the Principal Investigator (PI). contains three major components: (a) code dissector tubes 2, 3, and 4. 2. What am I going to receive? The PI to treat astrometric data (which arrive on will receive magnetic tapes containing the -Robert C. Bless the ground via the Astrometry and Engi data in FITS format, a listing of the con neering Data Processing telemetry channel tents of the tape, a summary of the observa rather than the Routine Science Data Pro tions (if it exists) which complements the cessing telemetry channel as is the case for information in the files, and hard copies of SPACE TELESCOPE SCIENCE INSTITUTE NEWSLETTER NOVEMBER 1991 PAGE 15
the data (either glossy photographs in are complex and unless you have had some Guaranteed Time Observers. This guide is the case of imaging data or plots for experience with them, we would strongly intended for users who wish to visit the the spectra). advise you to visit us. STScI, and provides current information on 3. When will I receive the tape? The 10. How can I arrange a visit to STSd? travel directions, on-site "logistics," techni data are received by the Data Archive Op Contact the User Support Branch (USB) cal and scientific support, remote and on erations Group (DAOG) approximately (800-544-8425 in the U.S. or 410-338- site information resources, hotels and res one day after they are taken. About 8 hours 4413, userid USB). We request that you taurants. Two short forms are also later the tape is written and sent to the PI (or give us two weeks advance notice that you included: one for user feedback and one for to the person indicated in the Data Distribu are coming. requesting institute documentation. The tion Form), or kept at the DAOG office un 11. Do I have to know IRAF!STSDAS guide was prepared by Sheryl Falgout with til picked up at STScl. before coming? No. Technical support staff help and input from many Institute staff. If 4. What is on the tape? The tape will can help you learn the data analysis system. you are considering a visit to the STScl, we have the raw (uncalibrated) data, plus all 12. Where do/ call if/ haveanSTSDAS strongly recommend that you contact the the files generated by the calibration pipe question? Call 410-338-5100, or send e User Support Branch and request a copy of line. There are routines in STSDAS for mail to userid HOTSEAT. the user's guide. reading the tape. 13.Howcan/ obtain copies ofnon-pro -Bruce Gillespie 5. Are the data calibrated? Maybe. The prietary data from the HST archive? See data that the PI will receive have been cali the article below (p. 18). OBSERVATION PROBLEM brated with the best currently available cali 14. Is there documentation available? REPORTS bration reference files. In some cases, how Yes, a large number of documents are ever, complete sets of reference files for all available covering all aspects of STScl, STScl is most interested in receiving the possible combinations of setups and fil HST, the scientific instruments, and data feedback from observers on the degree of ters are not yet available. Observers should reduction and analysis. Please download success of their HST observing programs. contact us (410-338-1082, userid ANALY the STEIS version of this article for a Earlier this year, we developed the HST SIS) for further information. See also the complete listing, or contact USB to Observation Problem Report (HOPR, discussion of WF/PC, flat fields earlier in request copies. known locally as a "hopper" and available this issue (p. 9). 15. What if/ am a European (ESA)HST from the User Support Branch), which is a 6. Are the calibration reference files in user? European HST users with their own form to be filled out by GOs and GTOs cluded on the tape I will receive? No, the data or with a desire to make extensive use when there are apparent problems with reference files are not routinely included in of the HST archive are strongly encouraged HST scientific and calibration data. This the data tape you will be receiving. How to visit the ST-ECF at ESO in Garching, form was devised both to provide us with ever, all the reference files are public and Munich. Staff at the ST-ECF are available invaluable information on how well HST is can be requested to recalibrate your to help users begin to reduce and analyze performing in a scientific sense and to offer observations. their data. Limited facilities mean that, after Principal Investigators (Pis) a way to re 7. Are the images deconvolved? No, the an exploratory phase at the ST-ECF, most quest rescheduling of failed observations. data are not deconvolved routinely. Soft of the analysis will take place at the user's If you determine that data from your ware for deconvolution of HST images and home institute but considerable assistance GO, GTO, or calibration programs are de spectra is available in STSDAS. can be given with instrument-specific ques fective in any way, please Jet us know by l 8. Are there PSFs that will help me tions and the full facilities of the archive are submitting a Problem Report, even if you deconvolve my images? STScl maintains a available for any recalibration work. In or are not requesting that the observations be library of point-spread functions (PSFs), der to arrange a visit to Garching, contact repeated. All types of problems should be both observed and calculated using the (e-mail on span/decnet) ESO::STDESK; reported, ranging from the obvious (e.g., no Telescope Image Modelling (TIM) soft (phone) +49 89 320 06 291 and ask for data due to loss of guide-star lock) to the ware developed in house. (TIM can be STDESK; (fax) +49 89 320 06 480, atten more subtle (e.g., signal-to-noise different downloaded from STEIS using anonymous tion STDESK; or contact Bob Fosbury at than expected). ftp.) ST-ECF. Each problem report is examined by 9. Is it useful to visit STSd for the data our Telescope Time Review Board and for ~aniel Golombek analysis? Yes! We strongly recommend warded to expert staff for analysis. When a that you visit us at least the first time you retake of a failed observation is specifically USER'S GUIDE TO THE STScl receive HST data. We have the facilities to requested by the PI, the Review Board will analyze your data. Also, all your instru We have just finished revising a short docu make a recommendation to the STScI Di ment-specific queries can be addressed im ment called "A User's Guide to the STScl," rector. 1lle decision to repeat the observa mediately by in-house experts. HST data and have mailed copies to the General and tion will be based on the investigation of SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER ~OVEMBER 1991 PAGE16
the problem, within the context of how re month of receipt If you have questions on if one wants to construct an astrometrically peating the observation would contribute to how to use the form or need additional cop "sensible" mosaic. And in any case, the the broader HST science program. ies, please contact the undersigned (410- long-term stability of the CCD positions It is important to note that STScl will 338-4723, userid GILLESPIE). relative to one another cannot be assessed not initiate the retaking offailed observa -Bruce Gillespie at the moment, so the advice to restrict one tions without an explicit request submitted self to a single chip for astrometry will re on an HST Observation Problem Report main valid. WF/PC-ASSISTED EARLY form and signed by the PI. The only excep -Roberto Gilmozzi tion to this policy is in the relatively rare ACQUISITIONS case of observations lost during telescope Some common problems related to and instrument "safing" events; observa WF/PC. early-acquisition images (i.e., im USERS' COMMITTEE MEETS tions lost due to safing will be rescheduled ages obtained in order to determine the tele The first meeting of the Space Tele automatically where possible. Otherwise, scope pointing for subsequent observations scope Users' Committee (STUC) in Cycle 1 we will only reschedule failed or defective with other instruments) may not have been was held on September 26-27, 1991. The observations when an explicit request has taken into proper account by some observ three major issues which the committee ad been received from a PI, following review ers. These problems are discussed in detail dressed were the recent changes to the WF/ and Director's approval. in the Target Acquisition Handbooks and in PC II capabilities, the problems with the In all cases, the analysis and disposition recent Phase II materials, but they are high GHRS, and the on-going operations of of Observation Problem Reports are com lighted again here. This article also de HST, including the experiences and recom municated to the PI, generally within a scribes the corrective actions that STScl mendations of the first General Observers is taking. (GOs). Joe Rothenberg, the HST Project Manager at GSFC, described the difficul SPACE TELESCOPE USERS' 1. WF!PC geometric distortion. This prob ties that the WF/PC. II development had en COMMITTEE lem affects the ability to perform accurate countered at JPL. Faced with risks to both relative astrometry within the WF/PC. field the on-orbit performance and development Arthur Davidsen (Chair) of view. The distortion is introduced by the schedules, the WF/PC II science team Johns Hopkins University WF/PC. optics, and the departure from lin agreed to a reduction in the number of relay Reta Beebe earity can be as high as 3 pixels over one camera/CCDs (from 4 to 3 in the Wide New Mexi.co State University CCD chip. We have obtained data to cali Field and from 4 to 1 in the Planetary Cam brate this distortion, and expect to have a Sa'ldra Faber eras) and the addition of on-orbit actuators preliminary calibration of W2 and P6 by University of California on two of the three Wide Field relays year's end, with the other chips following (thereby ensuring good on-orbit optical Edward Groth soon after. The calibration will be accom performance over most of the original field Princeton University panied by a STSDAS tool that will enable of view). The STUC expressed concern Lew Hobbs observers to go from the x,y positions di about the WF/PC. II development and rec University of Chicago rectly to right ascension and declination ommended the highest management atten without having to worry about the geomet John Hutchings (Vice-Chair) tion by NASA. ric correction. Note that the WF/PC. team NRC of Canada The STUC was briefed by Preston has recently circulated a correction Burch, a NASA manager, on the technical Robert Kirshner algorithm for the WFC based on a ray-trac status of the GHRS and the possible Harvard University ing program. workarounds to the failure of the side 1 Rolf Kudritzki 2. WF!PC mosaicking. The data gathered low-voltage power supply. The STUC rec Max Planck Inst.for Phys & Astr. for the calibration of the ge.ometric dis..or ommended to NASA that procedures for Simon Lilly tion will also provide a very good estim 1te switching data channels (which could re University of Toronto of the relative distance and rotation of the store the operation of GHRS side 2) be vali dated and that the method for restoring George Miley various CCDs with respect to each other. GHRS side 2 operations be established Leiden Observatory Until then, mosaicking of the CCDs v•ill prove difficult, and, as in the past, we do prior to the Time Allocation Committee Edward (Rob) Robinson not advise observers to attempt astromC'try deliberations. It also endorsed further study University of Texas across CCDs. Moreover, each chip is of recovering side 1 operations during the Rogier Windhorst treated independently by most of the soft next servicing mission. Arizona State University ware, and this will cause obvious problems While the experiences of the early GOs have generally been positive, several early SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE 17
GOs have taken the opportunity to commu a late-1993 servicing mission. Since the without further reductions in their capabili nicate some criticisms and recommenda scientific impacts of all three developments ties and cost as well as belt-tightening in tions to the STScI Director and the STUC are comparable and complementary, the other HST Project elements. Chair. These and the corrective actions be STAC did not attempt to prioritize among The members of the STAC for 1991-92 gun by the STScl were discussed at length. the three and urged tight management of are listed in the table. The STAC report Progress in the development of parallel ob their development. In this regard, the may be requested through the STScI servations and tracking moving targets was STAC commended the recent reduction of Director's Office. also reviewed. The STUC commended all the WF/PC. II as necessary to restore most -Peter Stockman elements of the HST program for achieving of the original HST capabilities by the earli a vastly improved level of operations. Fu est possible date. As for the relative priori STEIS USAGE INCREASES ture GOs are encouraged to communicate ties of the second generation instruments FIVE-FOLD any concerns to the STScl and/or the (STIS andNIC), the STAC considered both STUC. The members of the ST Users' instruments to offer compelling scientific The Space Telescope Electronic Infor Committee are listed in the table, along capabilities in the ultraviolet and near-IR mation Service (STEIS) is an anonymous with the elected Chair and Vice-Chair. compared to current ground-based facilities ftp (file transfer protocol) account set up and HST instruments. They urged NASA to over a year ago to provide current informa -Peter Stockman develop both instruments in parallel for an tion about HST to the astronomical com on-orbit installation targeted for 1997. The munity. Observers use STEIS to obtain ob STAC MEETING STAC recognized that, with instrument serving schedules, instrument status Partly in response to the power supply costs around $100 million each, such a par reports, information about (and source code failure in the GHRS, NASA formally re allel development would not be feasible for) calibration and data-analysis software, quested advice from the STScl Director and software to help in creating observing concerning the development and priorities proposals. The ftp address is stsci.edu. for future servicing missions. To consider SPACE TELESCOPE ADVISORY The figure shows that usage has in these issues from the broadest scientific COMMITTEE creased five-fold since the beginning of the perspective, Riccardo Giacconi recon year. The large jump in July resulted from vened the Space Telescope Advisory Com Jeremiah Ostriker (Chair) the August proposal deadline. This chart is mittee (STAC), with Jerry Ostriker as the Princeton University based on the number of times the string Chairman. Meeting on October 9-10, the Robert Gehrz "LOGIN" appears in our accounting file; ST AC received briefings from Joe University of Minnesota each login does not necessarily represent a Rothenberg, the HST Project Manager, on new user. All of the directories have shown Burton Jones the current development plans; from Bruce an increase in octivity-apparently STEIS University of California Woodgate and Rodger Thompson, the Pis users like to browse. for the Space Telescope Imaging Spec Christopher McKee A questionnaire about STEIS has been trometer (STIS) and Near Infrared Camera University of California posted on STEIS, and we have received (NIC); and from Ed Weiler, the acting HST George Preston many positive responses, as weJI as con Program Manager. The ST AC was also Mt. Wilson & Las Campanas structive criticisms and suggestions. Com provided extensive written material by the mon requests are for immediate notifica Blair Savage STIS and NIC science teams. Prior to the tion of newly posted items, on-line help, University of Wisconsin meeting, an independent technical review and greater ease in finding and download of the STIS, NIC, and COSTAR programs Steve Strom ing files. Some users have experienced was conducted by astronomers from the University of Massachusetts trouble making connections with a particu STScl and five other research institutions. Daniel Weedman lar brand of ftp, or arc not fluent with avail The results of that review were provided to Pennsylvania State University able commands (the system is based in the STAC and copies may be requested UNIX). For example, people often try to Sidney Wolff from the Chair of the review team, Chris download directories, mistaking them for NOAO Blades (userid BLADES). files. This problem is easily avoided by us In summary, the STAC recommenda Lodewijk Woltjer ing the "ls -F'' command to provide a list tions to the STScl (which generally com Observatoire de llaute Provence ing that distinguishes directory names prise the STScl response to NASA) place Donald y orlc from file names. the highest priority on restoring the capa University of Chicago The daily I/ST status reports written by bilities of the GHRS and the timely Joe Ryan of NASAJGSFC have answcced completion of WF/PC. II and COSTAR for the demand for up-to-date I/ST news, and SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE18
using STARCAT, which accesses stsci via telnet, is available upon request from the STEIS Usage in 1991 2695 User Support Branch. STARCAT can dis play a field specifying the date on which 2500 L______each observation will become public. (The normal proprietary period is one year, but some special observations may have shorter periods, including the Science As sessment and Early Release Observations 2000 and many calibration data.) Questions about the data archive may (/) c: be directed to Mario Livia, head of the O> STScl Data Management Facility (410- 0 ....J 338-4439, userid MLIVIO). 1500 -Mario Livio & Pete Reppert PROPRIETARY STATUS OF HST CALIBRATION DATA The following statements are intended to clarify the policies related to the avail ability and release of HST calibration data.
1. All HST data, including calibration data, 500 are immediately available to STScl instru ment and calibration scientists for evalua tion and analysis.
2. Calibration and engineering data ob tained as part of the STScl Calibration Pro Feb March April May June July August gram will become available to the astro nomical community as soon as the data are placed in the STScl archive. are probably the most popular item on HOW TO OBTAIN ARCHIVAL STEIS. Sometime in the future these re DATA 3. Calibration data obtained as part of ports might become accessible via telnet. Scientists who wish to obtain non-pro the OV/SV Program will become There are sometimes discrepancies in publicly available 30 days following the prietary archival HST data and who do not our HST scheduling information, which observation. seek funding for their Archival Research arise when the long-term scheduling is re may request copies of the data by filling out vised in the short term. We have some pos 4. Calibration data obtained as part of and theform "Request For Copy of HST Obser sible solutions for this problem, but may charged to approved GTO and GO pro vations," which is available from the User never be able to promise 100% concur grams have the same proprietary period as Support Branch or can be downloaded rence, since schedules are frequently modi the associated scientific data, typical1y one from STEIS (file observer/dsob2.ps). fied after the reports come out The weekly year, unless released earlier by the PI or n: A list of the thousands of archived HST timeline is usually the most reliable leased later following approval by the Insu images is available on STEIS, under the schedule. tute Director. Note that these data may also filename AEC.CAT ALCXJ in the obser. er/ As always, we welcome comments and be used, as appropriate, by STScl staff for completed_observations directory. suggestions. Anyone wishing to post infor updating the calibration pipeline. A request must specify the "root~ or mation relating to HST should contact -Kirk Borne "dataset" name of the desired data ~se the undersigned (410-338-4551, userid names can be obtained either from REPPERn. AEC.CATALCXJ or by querying the HST AN HST USER SURVEY: THE PRO There will be a poster paper on (and archive catalog using STAR CAT, a menu POSAL SUBMISSION SYSTEM probably a live connection to) STEIS at the driven archive-searching system which January 1992 AAS meeting in Atlanta In both Phase I and Phase TI of the pro works on any standard terminal. A gui~· to posal process, I/ST observers are required -Pete Reppert SPACE TELESCOPE SCIENCE INSTITUTE NEWSLE1TER NOVEMBER1991 PAGE 19
to fill out an electronic proposal template If the research was supported by a grant CYCLE 2 PROPOSAL STA TISTICS and use software (such as the Phase I from STScl, the publication should also Formatter and RPSS) that checks the pro the following acknowledgment at the carry Number of proposals by type: posal for syntactical and feasibility errors. end of the text The proposal is then submitted electroni "Support for this work was provided by GO 429 cally and is eventually translated directly NASA through grant number __ from GTO/Augmentation 38 into telemetry commands that are sent to the Space Telescope Science Institute, Snapshot 7 the spacecraft, which is why the proposal which is operated by the Association of Archival 9 file must be carefully constructed. Universities for Research in Astronomy, TOTAL 483 We will be upgrading the proposal sub Inc., under NASA contract NAS5-26555." Number of large proposals: 19 mission software in the coming year, and For our records, please send one pre Total time requested (all types and cycles): we are trying to identify hardware and soft print of any research paper based on HST ware improvements that will best serve the data to: Spacecraft 11,796 hrs HST user community. If you have ever sub Parallel 1,421 hrs Librarian mitted an HST observing proposal, Phase I Number of proposals and proposal fraction Space Telescope Science Institute and/or Phase II, the User Support Branch is by instrument (all types and requests): 3700 San Martin Drive interested in your comments and opinions Baltimore, Maryland 21218 WFJPC, 153 32% regarding the current proposal submission FOC 78 16% system. This includes the Phase I template Finally, please reference the relevant FOS 149 31% HST observing program identification and formatter; the Phase II RPSS template, GHRS 195 40% number(s) in your papers so that we can validation program, and spacecraft re HSP 9 2% cross-index scientific papers with the origi source estimator; and any other resources FGS 16 3% you have used. nal observing proposals. A questionnaire has been posted on If you have questions regarding these Number of proposals by Scientific Cat STEIS in the main directory, and may be instructions, please contact Bruce Gillespie egory (all types): downloaded, filled out, and returned to (410-338-4723, userid GILLESPIE) or Galaxies & Clusters 74 USB. This is your chance to let us know Sarah Stevens-Rayburn (410-338-4961, Interstellar Medium 92 how we can help with the difficult task of userid LIBRARY). Quasars & AGN 92 HST proposing and/or to vent your frustra -Bruce Gillespie & Sarah Stevens Solar System 46 tions with the current system in a construc R ayburn Stellar Astrophysics 135 tive way. Please return the questionnaire by Stellar Populations 44 January 17, 1992, by e-mail to userid USB. PROPOSAL NEWS Number of proposals by PI country Also, be sure to look for the STScl dis (*=ESA member state): play at the AAS meeting in Atlanta. The USB will be demonstrating software tools CYCLE 2 PEER REVIEW UNDER Australia 3 that are designed to assist HST proposers, WAY Austria* 1 Belgium• 1 and we hope to get some immediate feed The deadline for submission of Cycle 2 Canada 8 back from potential users. HST proposals occurred on August 16, China 1 1991. A total of 483 proposals was submit -Max Muichler France• 19 ted. The proposals have now been sent out Germany• 20 to the peer reviewers, who will meet al PUBLICATION OF HSTRESEARCH India 1 STScl in December to select programs to Israel 1 The rate of publication of HST results be recommended to the STScl Director for Italy* 17 continues to increase. We wish to remind implementation. Mexico 1 all authors again that research papers based Proposers will be notified of the out Netherlands* 5 on HST data should carry the following come in January and successful proposers South Africa 3 footnote: will then be asked to submit their Phase II Spain* 4 "Based on observations with the information. Cycle 2 observations arc ex Sweden* 4 NASNESA Hubble Space Telescope, ob pected to begin in the summer of 1992. Switzerland* 3 tained at the Spoce Telescope Science Insti The tables present some statisti-:s of the United Kingdom• 15 tute, which is operated by the Association Cycle 2 proposal pool. Not.c that large pro USA 374 of Universities for Research in Astronomy, posals are defined as those requesti:1g more USSR 2 Inc., under NASA contract NAS5-26555." than 100 hours of spacecraft and/or parallel SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE 20
PUBLISHED HST PAPERS 9. "First Results from the Faint Object Camera: High-Resolution The following is a list of published papers containing re Observations of the Central Object R136 in the 30 Doradus sults from HST. This list is maintained by the STScl Librarian, and Nebula," Weigelt. G., Albrecht. R., Barbeiri, C., Blades, J.C., the newest additions will be published in each Newsletter. Please Boksenberg, A., Crane, P., Deharveng,J.M., Disney, MJ., note that this list is for information only, and that preprints and re Jakobsen, P., Kamperman, T.M, King, I.R., Macchetto, F., prints of these papers are not available from STSd. Mackay, C.D., Paresce, F., Sparks, W.B., ApJ 378: L21-L23 (1991). 1. ''The Core of the Nearby SO Galaxy NGC 7457 Imaged with the HST Planetary Camera." Lauer, T .R., Faber, S.M, Holtzman, 10. ''First Results from the Goddard High-Resolution Spectro J.A., Bawn, W.A., Currie, D.G., Ewald, S.P., Groth, EJ., Hester, graph: The Chromosphere of Alpha Tauri," Carpenter, K.G., JJ., Kelsall, T., Kristian, J., Light. R.M., Lynds, C.R., O'Neil, Robinson, R.D., Wahlgren, G.M., Ake, T .B., Ebbets, D.C., EJ., Shaya, EJ., Westphal, J.A., ApJ 369: L41-L44 (1991). Linsky, JL., Brown, A., Walter, F.M, ApJ 377: L45-L48 (1991). 2. ''The Postcollapse Core of MIS Imaged with the HST Plan 11. ''First Results from the Goddard High-Resolution Spectro etary Camera," Lauer, T .R., Holtzman, J.A., Faber, S.M, Bawn, graph: Evidence for Photospheric Microturbulence in Early 0 W.A., Currie, D.G., Ewald, S.P., Groth, EJ., Hester, JJ., Kelsall, Stars: Are Surface Gravities Systematically Underestimated?," T., Kristian, J., Light. R.M, Lynds, C.R., O'Neil, EJ., Shaya, Hubney, I., Heap, S.R., Altner, B., ApJ 377: L33-L36 (1991). EJ., Schneider, D.P., Westphal, J.A., ApJ 369: L45-L49 (1991). 12. "First Results from the Goddard High-Resolution Spectro 3. "Faint Object Camera Observations of a Globular Cluster graph: High-Resolution Observations of the 1942 A Resonance Nova Field," Margan, B., Anderson, S.F., Downes, R.A., Bohlin, Line of Hg II in the Chemically Peculiar B Star, Chi Lupi," R.C., Jakobsen, P., ApJ 369: L71-L74 (1991). Leckrone, D.S., Wahlgren, G.M., Johansson, S.G., ApJ 377: L37- L40 (1991). 4. ''The Imaging Performance of the Hubble Space Telescope," Burrows, CJ., Holtzman, J.A., Faber, S.M., Bely, P.Y., Hasan, 13. ''First Results from the Goddard High-Resolution Spectro H., Lynds, C.R., Schroeder, D., ApJ 369: L21-L25 (1991). graph: C I, S I, and CO toward Xi Persei and the Physical Conditions in Diffuse Clouds," Smith, A.M, Bruhweiler, F.C., 5. "Binary Star Observations with the Hubble Space Telescope Lambert, D.L., Savage, B.D., Cardelli, J .A., Ebbets, D.C., Lyu, Fine Guidance Sensors. I. ADS 11300," Franz, O.G., Kreidl, C., Sheffer, Y., ApJ 377: L61-L64 (1991). TJ.N., Wasserman, L.W., Bradley, AJ., Benedict. G.F., Hemenway, P.D.,Jefferys, W.R. McArthur, B., McCarthey, J.E., 14. "First Results from the Goddard High-Resolution Spectro Nelan, E., Shelus, P J., Story, D., Whipple, A.L., Duncombe, graph: A Demonstration and Experiments with Deconvolution," RL.,Fredrick, L.W., van Altena, Wm.F., ApJ 377: L17-L20 Wahlgren, G.M., Leckrone, D.S., Shore, S.N., Lindler, DJ., (1991). Gilliland, R.L., Ebbets, D.C., ApJ 377: L41-L44 (1991). 6. "HST Observations of 3C 66B: A Double-Stranded Optical 15. "HST Imaging of the Inner 3 arcseconds ofNGC 1068 in the Jet," Macchetto, F., Albrecht. R., Barbieri, C., Blades, J.C., Light of [01m A. 5007," Evans, I.N .• Ford, H.C., Kinney, A.L., Boksenberg, A., Crane, P., Deharveng, J.M., Disney, MJ., Antonucci, R.RJ., Armus, L., Caganoff, S., ApJ 369: L27-L30 Jakobsen, P., Kamperman, T.M., King, I.R., Mackay, C.D., (1991). Paresce, F., Weigelt. G., Baxter, D., Greenfield, P., Jedrzejewski, 16. "NGC 1068: Resolution of Nuclear Structure in the Optical RF., Weigelt. G., Nata, A., Sparks, W.B., Miley, GK., ApJ 373: Continuwn," Lynds, R., Faber, S.M, Groth, EJ., Holtzman, J.A., L55-L58 (1991). Light. R.M., O'Neil, EJ., Bawn, W.A., Currie, D.G., Ewald, S.P., 7. ''Properties of the SN 1987 A Circwnstellar Ring and the Hester, JJ., Kristian, J., Shaya, EJ., Seidelmann, P.K., Westphal, Distance to the Large Magellanic Cloud," Panagia, N., Gilmozzi, J.A., ApJ 369: L31-L34 (1991). R., Macchetto, F., Adorf, H.-M, Kirshner, R.P., ApJ 380: L23- 17. "Ionization Fronts and Shocked Flows: The Structure of the L26 (1991). Orion Nebula at 0·:1," Hester, JJ., Gilmozzi, R., O'Dell, C.R., 8. "Blue Stragglers in the Core of the Globular Cluster 4 7 Faber, S.M. Campbell, B., Code, A., Currie, D.G., Danielson, Tucanae," Paresce, F., Shara, M., Meylan, G., Baxter, D., G.E., Ewald, S.?.• Groth, EJ., Holtzman, J.A., Kelsall, T., Lauer, Greenfield, P., Jedzejewski, R.F., Weigelt. G., Nata, A., Sparks, T .R., Light. R.M., Lynds, R., O'Neil, EJ., Shaya, EJ., Westphal, W.B., Macchetto, F., Albrecht. R., Barbieri, C., Blades, J.C., J.A., ApJ 369: L75-L78 (1991). Boksenberg, A., Crane, P., Deharveng,J.M, Disney, MJ., 18. "Hubble Space Telescope Imaging of Eta Carinae," Hester, Jakobsen, P., Kamperman, T.M, King, I.R., Mackay, C.D., JJ., Light. R.M., Westphal, J.A., Currie, D.G., Hunter, D., Baum, Nature 352: 297-301 (1991). W.A., Campbell, B., Code, A., Ewald, S.P., Kelsall, T., Lauer, SPACE TELESCOPE SCIENCE INSTITUTE NEWSLETTER NOVEMBER 1991 PAGE21
T.R., Lynds R., O'Neil, EJ., Shaya, EJ., Schneider,D.P., 27. ''First Results from the Goddard High-Resolution Spectro Seidlemann, P.K.,Westphal, J.A., AJ 102: 654-657 (1991). graph: Resolved Velocity and Density Structure in the Beta Pictoris Circumstellar Gas," Boggess, A., Bruhweiler, F.C., 19. "Stellar Photometry with the Hubble Space Telescope Wide Grady, C.A., Ebbets, D.C., Kondo, Y., Trafton, L.M., Brandt, Field/Planetary Camera: A Progress Report," Holtzman, J.A., J.C., Heap, S.R., ApJ 377: 1A9-L52 (1991). Groth, EJ., Light, R.M., Faber, S.M, Currie, D.G., Ewald, S.P., Hester, JJ., Light, R.M, Lynds, C.R., O'Neil, EJ., Seidelmann, 28. ''The lntraviolet Absorption Spectrum of 3C 273," Bahcall, PK., Shaya, EJ., Smith, A.M, ApJ 369: L35-1AO (1991). JN., Jannuzi, B.T., Schneider, D.P., Hartig, GF., Bohlin, R., Junkkarinen, V., ApJ 377: L5-L8 (1991). 20. "Hubble Space Telescope Wide-Field/Planetary Camera Images of Saturn," Westphal, J.A., Baum, W.A., Lauer, T .R., 29. "First Results from the Goddard High-Resolution Spectro Danielson, G.E., Currie, D.G., Ewald, S.P., Faber, S.M, Groth, graph: Ultraviolet Spectra of a Starburst Knot in NGC 1068," EJ., Hester, JJ., Light, RM., Lynds, R., O'Neil, EJ., Hutchings, J.B., Bruhweiler, F., Boggess, A., Heap, S.R., Ebbets, Seidelmann, P.K., Shaya, EJ., Smith, B.A., ApJ 369: L51-L53 D., Beaver, E., Rosenblatt, E., Truong, K.Q., Perez, M, (1991). Westmacott, R., ApJ 377: L25-L28 (1991).
21. ''Far-Ultraviolet Spectroscopy of the Quasar UM 675 with the 30. "First Results from the Faint Object Camera: High Resolution Faint Object Spectrograph on the Hubble Space Telescope," Imaging of the Pluto-Charon System," Albrecht, R., Barbeiri, C., Beaver, E.A., Burbidge, E.M, Cohen, R.D., Junkkarinen, T., Blades, J.C., Boksenberg, A., Crane, P., Deharveng, J.M. Lyons, R.W., Rosenblatt, E.I., Hartig, G.E., Margan, B., Disney, J.M. Jakobsen, P., Karnperman, T.M, King, I.R., Davidsen, AF., ApJ 377: Ll-lA (1991). Macchetto, F., Mackay, C.D., Paresce, F., Weigelt, G., Baxter, D., Greenfield, P., Jedrzejewski, R., Nata, A., Sparks, W.B., ApJ 22. "First Results from the Faint Object Camera: Images of the 374: L65-L67 (1991). Gravitational Lens System G2237+0305," Crane, P., Albrecht, R., Barbieri, C., Blades, J.C., Boksenberg, A., Deharveng, JM., 31. "FOS Spectroscopy of Resolved Structure in the Nucleus of Disney, J.M. Jakobsen, P., Karnperman, T.M, King, I.R., NGC 1068," Caganoff, S., Antonucci, R.RJ., Ford, H.C., Kriss, Macchetto, F., Mackay, C.D., Paresce, F., Weigelt, G., Baxter, GA., Hartig, G.F., Armus, L., Evans, I.N., Rosenblatt, E., D., Greenfield, P., Jedrzejewski, R., Nata, A., Sparks, W.B., ApJ Bohlin, R.C., Kinney, A.L., ApJ 377: L9-Ll2 (1991). 369: L59-L61 (1991). 32. ''Faint Object Spectrograph Observations of the Low 23. "First Results from the Faint Object Camera: SN 1987A," Luminosity Seyfert Galaxy NGC 1566," Kriss, G.A., Hartig, Jakobsen, P., Albrecht, R., Barbieri, C., Blades, J.C., Boksenberg, GF., Armus, L., Blair, W .P., Caganoff, S., Dressler, L., ApJ 377: A., Crane, P., Deharveng, J.M., Disney, J.M., Jakobsen, P., L13-Ll6 (1991). Karnpennan, T.M., King, LR., Macchetto, F., Mackay, C.D., 33. "First Results from the Goddard High-Resolution Spectro Weigelt, G., Baxter, D., Greenfield, P., Jedrzejewski, R., Nata, graph: Spectroscopic Determination of Stellar Parameters of A., Sparks, W.B., ApJ 369: L63-L66 (1991). Melnick 42, an 03f Star in the Large Magellanic Cloud," Heap, 24. ''First Results from the Faint Object Camera: Observations of S.R., Altner, B., Ebbets, D., Hubney, L, Hutchings, J.B., PKS 0521-36," Macchetto, F., Albrecht, R., Barbieri, C., Blades, Kudritzki, R.P., Voels, S.A., Haser, S., Pauldrach, A., Puls, J., J.C., Boksenberg, A., Crane, P., Deharveng, J.M., Disney, J.M., Butler, K., ApJ 377: L29-L32 (1991). Jakobsen, P., Karnperman, T.M, King, LR., Mackay, C.D., 34. ''The Current Ability of HST to Reveal Morphological Paresce, F., Weigelt, G., Baxter, D., Greenfield, P., Jedrzejewski, Structure in Medium-Redshift Galaxies," King, LR., Stanford, R., Nata, A., Sparks, W.B., ApJ 369: L55-L57 (1991). SA., Seitz.er, P .• Bershady, MA., Keel, W.C., Koo, D.C., Weir, 25. ''First Results from the Faint Object Camera: Imaging the N., Djorgovski, S., Windhorst, R.A., AJ 102: 1553-1568 (1991). Core of R Aquarii," Paresce, F., Albrecht, R., Barbieri, C., 35. "First Results from the Goddard High Resolution Spec Blades, J.C., Boksenberg, A., Crane, P., Deharveng, J.M. trograph: Element Abundances as a Function of Velocity in the Disney, J .M, Jakobsen, P., Karnperrnan, T.M., King, I.R., Neutral Gas toward Xi Persei," Savage, B.D., Cardelli, G.A., Mackay, C.D., Weigelt, G., Baxter, D., Greenfield, P., Bruhweiler, F.C., Smith, A.M., Ebbets, D., Sembach, K.R., ApJ Jedrzejewski, R., Nata, A., Sparks, W.B., ApJ 369: L67-L 70 377: L53-L56 (1991). (1991). 36. "First Results from the Goddard High-Resolution Spectro 26. ''First Results from the Goddard High Resolution Spectro graph: Elcrrv!ntal Abundances in the Diffuse Clouds toward Xi graph: The Galactic Halo and the Lyman Alpha Forest at Low Persei," CarJelli, J.A., Savage, B.D., Bruhweiler, F.C., Smilh, Redshift in 3C 273," Morris, S.L., Weymann, RJ., Savage, B.D., A.M., Ebbel•. D .• Sembach, K.R., Sofia, VJ., ApJ 377: L57-L60 Gilliland, R.L., ApJ 377: L21-L2A (1991). (1991). SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE22
time. The proposal fractions by scientific recalibrate their data. Since the launch of AURA will miss Jay Gallagher, who instrument total more than 100%, since HST, substantial revisions and enhance has served as Vice President since June some proposals have requested more than ments have been made to the header 1989. Dr. Gallagher took up a position on one instrument records of HST data files. The bulk of these the faculty of the University of Wisconsin changes are scheduled to be implemented on August 1 as Professor of Astronomy. -Kirk Borne & Howard E. Bond by the time STSDAS Vl.2 is released. The During his appointment at AURA, he con header changes are being done in prepara tributed significantly to the development of APPROVED DIRECTOR'S DISCRE tion for a reprocessing of all HST data taken the Gemini telescopes project and worked TIONARY PROGRAMS since launch. This reprocessing is intended closely with the astronomy community.Jay The following Director's Discretionary to populate the raw and processed data will continue his association with AURA programs have been approved since the last headers, and the data bases, with more cor as a senior scientific advisor. rect and/or complete information, and to issue of the Newsletter (PI and Proposal -Goetz Oertel & Lorraine Reams Title>: recalibrate the data with improved calibra tion reference files. As the headers have S. Shore, High Resolution Observations of BOARD MEMBER TO SERVE ON Nova IMC 1991 (unsuccessful due to changed, so has the ·calibration software. However, until all the data are reprocessed, PRESIDENTIAL SCIENCE GHRS failure) COMMITIEE C. Leitherer, UV Spectropolarimetry ofAG a few incompatibilities will exist between Car in its Current Outburst some data files as they currently exist in the Congratulations! President Bush has J. Bahcall, Gravitational Lens Candidate archive and the most recent version appointed France C6rdova, AURA Direc 1208+101: Photometry (CAL.xxx) of the STSDAS calibration tasks. tor-at-Large from Pennsylvania State Uni The most substantial revisions affect the versity, to the President's Committee on the -Kirk Borne GHRS and FOS. National Medal of Science. In order to provide continued access to -Goetz Oertel & Lorraine Reams SOFTWARE NEWS currently archived data for recalibration, we provide all older versions of the CAL.xxx STSDAS NEWS tasks in the pipeline package. A translation HUBBLE FELLOWSHIP task is now available in each of the hrs and PROGRAM The next major release of the Space fos packages to make the headers compat Telescope Science Data Analysis Software ible with Version 28 of SOGS. Users THIRD SELECTION CYCLE UNDER (STSDAS Version 1.2) will be available by should run the task pipeline.versions to see WAY the end of this year. This release is being which version of the software was used for coordinated with the next release of IRAF, the initial calibration of their data, and be The Announcement of Opportunity for Version 2.10. Some 94 new tasks have aware that choosing the most appropriate the third round of competition for Hubble been added to STSDAS since the release of version of the software and calibration ref Postdoctoral Fellowships was issued at the Vl.1, including both instrument-specific erence files may require some consultat'on beginning of September 1991. The dead tasks and general-purpose tools. Several with Institute staff. line for submitting applications was No other tasks, including those for pipeline vember 15. The applications received by data reduction, have undergone major revi -Dick Shaw & Bob Hanisch that time will be considered by the Review sion and/or enhancement Panel that meets in late January 1992. Of Many of the new tasks are intended to AURA NEWS fers to successful candidates will be made facilitate the analysis required to generate by February 1, 1992. Further information the calibration reference files for each in AURA APPOINTS NEW VICE on the Hubble Fellowship Program can be strument, while several others provide ad PRESIDENT obtained from Nino Panagia (410-338- ditional plotting and analysis capabilities. 4916, userid PANAGIA), or by e-mail to As with all STSDAS software, these new The Association of Universities fm Re userid HFELLOWS. tasks support the GEIS (or multi-group) search in Astronomy (AURA), Inc. is pleased to announce the appointment of format data structures that are used for HST FIRST HUBBLE SYMPOSIUM data files. Some of the new tasks also use Harry W. Feinstein as Vice President for the Data Quality Files to mask bad pixels Administration, effective Septembc1 1, On October 22-23, 1991, the current from a calculation or operation, where rel 1991. Mr. Feinstein, formerly Head of J.. d Hubble Fellows met at STScl to present evant ministration at the Space Telescope Sci and discuss the results of their Hubble Fel One new package, pipeline, may be of ence Institute, has over 25 years of experi lowship research projects. It is expected particular interest for users who wish to ence as a professional business manar,er that the Hubble Symposium will be an an (including 6 years with STScI). nual event SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE 23
The Hubble Fellows who gathered at STSd for the First Annual Hubble Symposium are shown in a picture taken on October 22, 1991. Left to right; front row: Paul Callanan, Young-Wook Lee, Mario Mateo, Stefl Baum, Laura Danly, Janet Wood, Riccardo Giacconi (STSd Director), Nino Panagia (HF Program Head), Qingde Wang, Dennis "Zaritsky, Neal Katz, Ken Lanzetta; second row: Michael Dopita (Session Chair), Colin Norman (Session Chair), Brian Yanny, Marijn Franx, Sean Ryan, Chuck Steidel, Peter Lundqvist, Mike Bolte, Pawel Artymowicz, Konrad Kuijken.
INSTITUTE NEWS by the SERC J survey. In addition we ex distribution of digitized surveys by STScl pect to add other digitized surveys to this will be done on a cost-recovery basis. A DIGITAL AU-SKY SURVEY collection as appropriate arrangements are The per-copy cost of the all-sky digi completed. tized survey will depend on the number of As part of the effort to construct the With the cooperation and encourage copies ordered. If demand is about 100 or Guide Star Catalog (GSC), STScl digitized ment of Caltech, the National Geographic ders, then the survey cost should be ap Schmidt plates covering the entire sky. The Society, the UK Science and Engineering proximately $6,000 per complete set, and if plate collection consists of materials from Research Council, and NASA, the STScl is 500 orders are received, the cost per set the UK Schmidt in Siding Spring, Austra currently planning to distribute moderately should be reduced to under $1,500. lia, operated by the Royal Observatory compressed images of the digital scans. Of the many different mass-storage and Edinburgh until June 1988 and thereafter Extensive tests have shown that essentially distribution media in widespread use, CD by the Anglo Australian Observatory, and no astrometric or photometric information R OMs (Compact Disk Read Only from the Oschin telescope on Palomar is lost through the compression and decom Memory) appear to be the most stable and Mountain, operated by the California Insti pression processes. Relative positional ac cost-effective technology available. We tute of Technology. These digitized scans curacies significantly better than 1 arcsec propose to distribute the survey as a set of (of order 1012 bytes of data) are stored on ond, and stellar brightnesses accurate to about 100 CDs. Software to read, decom optical disks at STScl. Details of the digiti better than 0.5 mag, are routinely obtained press, and display sky images on certain zation program, in particular the survey except near plate flaws and edges. The workstations, and to obtain celestial coordi and scan characteristics, are described in compression algorithms and tests were re nates from the images, will also be distrib the Astronomical Journal (1990, AJ, ported at the Digital Optical Sky Surveys uted free of charge to survey customers. 99,2019). Conference in Edinburgh this past June, If your institution might be interested in The purpose of this announcement is to and the report will also appear as an STScl purchasing a CD copy of the digitized sky ask whether your institution might be inter preprint survey, please contact Michael Shara at ested in purchasing a copy of the digitized The breadth of the communi~ .merest STScl (410-338-4743, userid SHARA). Be sky. The northern sky images that will be will enable STScl to decide whether to pro sure to indicate the type of workstation and offered are from the original POSS E (red) ceed with the survey distribution ar..d to es operating system you would prefer to use plates. The southern sky will be covered timate better the costs of producticn. Any with the digitized scans. Such preliminary expressions of interest, of course, imply no WORKSHOP ON STATUS OF Tim Heckman (410-338-4442, userid commitment to purchase the survey. WOMEN IN ASTRONOMY HECKMAN), at STScl. It will be helpful if candidates include a recent curriculum vi ~ichael Shara The Space Telescope Science Institute tae and a short description of their research is planning a workshop on the Status of plans. YEAR OF FIRST LIGHT PROCEED Women in Astronomy, to be held at STScl INGS AVAILABLE on September 3-4, 1992. The workshop -Tim Heckman will be geared toward graduate students, The Proceedings for the Year of First post-docs, junior and senior astronomers, RECENT STAFF CHANGES Light workshop held at STScl May 14-16, and administrators. The agenda will in Mario Livio has joined STScl as As 1991 are now published and are being sent clude discussion of the current status of tronomer and Chief of the Data Systems to Guest Observers, Guaranteed Time Ob women in the field, the particular chal Operations Branch. Mario comes to us servers, members of the Instrument Devel lenges women face, and ways to improve of the STScl pro ~om the Technion Institute of Technology opment Teams, members the recruitment and retention of women in posal panels, and to university libraries. m Israel and has much experience with re astronomy. search and teaching in Physics and As Copies will also be available at the 179th The organizing committee for the tronomy. His research interests include meeting of the American Astronomical So workshop includes (*=local): Neta Bahcall, theoretical studies of novae, supernovae, ciety, held in Atlanta, Georgia. There is a Peter Boyce, France C6rdova, Laura accretion disks, and the interactions of limited number of additional copies avail Danly*, Doug Duncan*, Riccardo Giac close binary stars. Mario will be taking able. If you would like one, please contact coni*, Anne Kinney*, Ethan Schreier*, Sarah Stevens-Rayburn, STScl Librarian over DSOB from Jerry Sellwood, who is Meg Urry*, and Sidney Wolff. If you are (userid LIBRARY). leaving the Institute for a position at interested in receiving further details about Rutgers University. the workshop, including registration infor New Assistant Astronomer Stefl Baum OCTOBER MINI-WORKSHOP mation, please contact: Barb Jedrzejewski, was most recently a Hubble Postdoctoral Conference Coordinator (410-338-4836, The final STScl mini-workshop of the Fellow at Johns Hopkins University. She userid ELLER), or one of the local organiz year, attracting more than 70 participants to has joined the SCARS/DSOB as the ers (userids DUNCAN, GIACCONI, Baltimore on October 8-10, 1991, con archive scientist. Her research centers on KINNEY, SCHREIER, CMU). cerned "Nonisotropic and Variable Out optical and radio observations of extra flows from Stars." Theoretical models rely ~egUrry nuclear signs of activity in active galaxies. largely on the idea that stars and their envi Rex Saffer has joined the Institute as an ronments can be described under the as SABBATICAL & LONG-TERM STScl postdoctoral fellow. He recently sumption of spherical symmetry and time VISITORS AT STScl completed his Ph.D. at the University of independence. However, recent obser Arizona, and specializes in spectroscopic In order to promote the exchange of vational data-including HST results studies of hot subdwarfs, single and binary ideas and collaborations in HST-related suggest that the outflow properties are white dwarfs, and horizontal-branch stars. science, STScl expects to provide limited widely dominated by disks, jets, and Brad Whitmore has been appointed funds to support visiting scientists who clumps, which often display significant Associate Astronomer with tenure. He con wish to spend extended periods of time time variability. A variety of objects, in tinues as Deputy Division Head of the Sci (three to twelve months), typically on sab cluding pre-main-sequence stars, early ence Programs Division. batical leave from their home institutions or type stars, and novae were discussed during After seven years of enthusiastic ser during the summer, doing research at the workshop, and the need for more elabo vice, Colin Norman has stepped down as STScl. rate models and observations was empha Head of the Academic Affairs Division to In general, these visitors will have a sta sized. devote more time to research. Nino tus similar to STScl employees and have . The ~gs of this mini-workshop Panagia, at STScl since September 1984, access to the facilities available to staff will be published in the Astronomical Soci and on the Academic Affairs staff since members. ety of the Pacific Conference Series. July 1988, will assume the position of Head Established scientists who might be in -Claus Leitherer of Academic Affairs on December 1, 1991. terested in such a visit during the summer Nino has wide-ranging research interests of 1992 or during the academic year com but is perhaps best known for his recent mencing in September 1992 should se!l1 a study of SN1987A with the HST, in which letter specifying the suggested period he determined an extremely accurate dis for the visit and other relevant details tance to the LMC via analysis of the ring to the Visiting Scientist Program, c/o around the supernova SPACE TELESCOPE SCIENCE INSTITUTE NEWSLErfER NOVEMBER1991 PAGE 25
RECENT STScl PREPRINTS 562. "Fanaroff-Riley I Galaxies as the Par 577. "Polarization Variability among ent Population of BL Lacertae Objects. Wolf-Rayet Stars. VII. The Single Stars in The following papers have appe.ared re m. Radio Constraints," C.M. Urry, P. WR 14, WR25andWR69,"L.Drissen,C. cently in the STScI Preprint Series. Copies Padovani, and M. Stickel. Robert, and AFJ. Moffat may be requested from Sharon Toolan 563. "A Model for Tidally Driven Eccen 578. "Discovery of a Low-Redshift (410-338-4898, userid TOOLAN) at tric Instabilities in Fluid Disks," S.H. Ultraluminous 'E+A' Galaxy," W.R. STScl. Please specify the preprint number Lubow. Oegerle, J.M. Hill, and J.G. Hoessel. when making a request 564. "Simulations of Tidally Driven Ec 579. "Inverse-Compton Gamma Ray Emis 548. ''New Wolf-Rayet Stars in Galactic centric Instabilities with Application to sion from Chaotic, Early-Type Stellar Open Clusters: Sher 1 and the Giant H II Superhumps," S. H. Lubow. Winds and its Detectability by GRO," W. Region Core Westerlund 2," A.FJ. Moffat, 565. "The Current Ability of HST to Reveal Chen and RL. White. M.M. Shara, and M. Potter. Morphological Structure in Medium-Red 580. "Coronal Lines and Starburst Features 549. "A Deep Survey for Galactic Wolf shift Galaxies," I.R. King, S.A. Stanford, P. in the Two New IRAS AGN: IRAS 04493- Rayet Stars. I. Motivation, Search Tech Seitzer, M. Bershady, W.C. Keel, D.C. 6441 and IRAS 22419-6049," S. Lipari and nique, and First Results," M.M. Shara, Koo, N. Weir, S. Djorgovski, and R. F. Macchetto. AFJ. Moffat, LF. Smith, and M. Potter. Windhorst 581. "Binary-Star Observations with the 550. "A Radio-Quiet Galaxy at Redshift 566. "Optical Synchrotron Emission and Hubble Space Telescope Fine Guidance z=3.409," D.A. Tumshek, F. Macchetto, Turbulence in Extragalactic Jets," D. Fraix Sensors," O.G. Franz, L.H. Wasserman, E. M V. Beneke, C. Hazard, W.B. Sparks, and Bumet Nelan, M.G. Lattanzi, B. Bucciarelli, and R.G. McMahon. 567. "'The Formation of Globular Clusters L.G. Taff. 551. "Accretion-Disk Phenomena," J.E. in Merging and Interacting Galaxies," 582. "Luminosity Functions, Relativistic Pringle. K.M. Ashman and S.E. Zepf. Beaming, and Unified Theories of High 552. "Spectroscopy of Spatially Extended 568. "Two High-Velocity Stars Shot out Luminosity Radio Sources," P. Padovani Material around High-Redshift Radio from the Core of the Globular Cluster 47 and C.M. Urry. Loud Quasars," T.M. Heckman, M.D. Tucanae," G. Meylan, P. Dubath, and M. 583. "Wind Accretion by Compact Ob Lehnert, G.K. Miley, and W. van Breugel. Mayor. jects: the 'Flip-Flop' Instability," M. Livio. 553. "On the Evolutionary Status of Beta 569. "Modelling the Evolution of Galaxies 584. "IRAS 02366-3101: An Accretion Pictoris," F. Paresce. in Compact Groups," S.E. Zepf and B.C. Disk Candidate among Luminous IRAS 554. "QSO Absorption Systems and the Whitmore. Galaxies," L. Colina, S. Lipari, and F. Origin of the Ionizing Background at High 570. "Optical Colors of Early-Type Galax Macchetto. Redshift," P. Madau. ies in Compact Groups," S.E. Zepf, B.C. 585. "Gas Flows in Spirals and Bars," J .A. 555. "Confirmation of Dust in Damped Whitmore, and HF. Levison. Sell wood. Lyman-Alpha Systems," Y.C. Pei, S.M. 571. "Proton-Initiated Electron-Positron Fall, and J. Bechtold. Pair Production in Compact Sources," A.A. 556. "Attenuation of Lyman-Alpha Emis GRADUATE STUDENT RESEARCH Zdziarski. sion by Dust in Damped-Lyman-Alpha ASSISTANTSHIPS 572. "The Distribution of Nearby Rich Systems," S. Charlot and S.M. Fall. Clusters of Galaxies," M. Postman, J.P. STScI invites applications from ad 557. "Subgiant CH Stars. II. Chemical Huchra, and MJ. Geller. vanced graduate students to pursue Ph.D. Compositions and the Evolutionary Con 573. "Outbursts by Low-Mass White thesis-level research with members of the nection with Barium Stars," R.E. Luck and Dwarfs in Symbiotic Variables," E.M. Sion Institute staff. The scientific fields repre HE.Bond. and CJ. Ready. sented at the Institute cover much of mod 558. "Implications of Helium Diffusion for 574. "Search for Starbursts among X-ray em astronomy, including theoretical, ob Globular-Cluster Isochrones and Luminos servational, and instrumental programs. ity Functions," C.R. Proffitt and D.A. Selected Galaxies: Optical Spectroscopy," A. Fruscione and RE. Griffiths. Since STScI is not a degree-granting VandenBerg. 575. "Properties of the SN 1987 A Circums organization, all students must be enrolled 559. "Polarized Radio Emission from the tellar Ring and the Distance to the Large in the graduate program at their home uni Edge-On Spiral Galaxies NGC 891 and Magellanic Cloud," N. Panagia, R. versity. Applicants must have completed NGC 4565," S. Sukumar and RJ. Allen. Gilmozzi, F. Macchetto, H.M. Adorf, and all required graduate course work and have 560. "Gravitational Settling in Solar Mod R.P. Kirshner. been admitted to the Ph.D. program at their els," C.R. Proffitt and G. Michaud. 576. "Eclipse Studies of the Dwarf Nova home university, which must give permis 561. "The Relationship between the CO In HT Cas. II. White Dwarf and Accretion sion for them to work at STScl. An affilia tensity and the Radio Continuum Emission Disk," J.H. Wood, K. Home, and S. tion with The Johns Hopkins University in Spiral Galaxies," D.S. Adler, RJ. Allen, Vennes. may be arranged for students while they are andK.Y.Lo. in Baltimore. SPACE TELESCOPE SCIENCE INSTITUTE NEWSLEITER NOVEMBER 1991 PAGE 26
The program is intended for students (410-516-8611) and the SDAS Hot Seat cal Society. If you have difficulty reaching who will spend at least one year at the Insti (410-516-5100). If an individual staff someone, please send the mail to the User tute, but proposals for shorter visits will member's extension is not known, call the Support Branch (userid USB), which will also be considered. Applications from stu STScl receptionist at 410-338-4700. forward it The USB is the central point of dents at both U.S. and foreign institutions contact for scientists who wish to conduct Fax: 410-338-4767 are invited. Applications for this program research with HST. should be sent to the Personnel Manager, Mail: STScl Space Telescope Science Institute, 3700 3700 San Martin Drive San Martin Drive, Baltimore, MD 21218, Baltimore, MD 21218 NEWSLETTER NOTES and should be clearly marked "Graduate USA Comments on the STScI Newsletter Student Program." They should include a E-mail: It is possible to reach most staff should be addressed to the Editors, Howard curriculum vitae, a statement of research members at STScl on NSI/DECnet (for E. Bond (410-338-4718, userid BOND) interests, and a letter from their advisor or merly known as SPAN), BITNET, and and Meg Urry (410-338-4593, userid departmental chair giving permission for Internet Address formats are as follows: CMU). Mailing-list corrections should be the student to work at STScl. Applicants sent to Amy Connor (userid CONNOR). should arrange for their transcripts and NSl/DECnet: stscic::userid Persons who assisted in the preparation three lette.rs of recommendation to be sent or 6559::userid of this issue include John Godfrey, Dave directly to the Personnel Manager. The BITNET: [email protected] Paradise, and Pete Reppert deadline for receipt of applications is Feb The STScl Newsletter is issued three to ruary 1, 1992. EOE/AAE Internet: [email protected] four times a year by the Space Telescope In most, but not all, cases the "userid" is ESA FELLOWSHIPS AT STScl Science Institute, which is operated by the the staff member's surname. Alternatively, Association of Universities for Research in Astronomers of European Space many userids are published in the Member Astronomy, Inc., for the National Aeronau Agency (ESA) member countries are re ship Directory of the American Astronomi- tics and Space Administration. minded of the possibility of coming to STScI as ESA Fellows. Prospective fellow ship candidates should aim to work with a particular member or members of the ESA staff at STScI, and for this reason applica tions must be accompanied by a supporting ST-ECF letter from STScl. Details of the interests of staff members at STScI can be obtained from Dr. J.E. N letter Pringle in the Academic Affairs Division (410-338-4477, userid PRINGLE). Details The Space Telescope - European Coordinating of the fellowships and application proce Facility publishes a quarterly newsletter which, dures can be obtained from the Education although aimed principally at European Space Office, ESA, 8-10 rue Mario Nikis, 75738 Telescope users, contains articles of general interest Paris 15, France. Completed application to the HST community. If you wish to be included in forms must be submitted through the ap the mailing list, please contact the editor and state propriate national authority and should your affiliation and specific involvement in the Space reach ESA no later than March 31 for con Telescope project. sideration in May, and no later than Sep tember 30 for consideration in November. Robert Fosbury (Editor) HOW TO CONTACT STScl Space Telescope - European Coordinating Facility Karl Schwarzschild Str. 2 Telephone: The area code for Baltimore D-8046 Garching bei MOnchen has changed from 301 to 410. Thus the tele Federal Republic of Germany phone numbers for staff members are now Telephone: +49 89 32006235 of the form 410-338-xxxx, where xxxx is E-Mail SPAN ESO::RFOSBURY the extension number. Two exceptions Bitnet RFOSBURY@DGAES051 are the Grants Administration Branch Internet [email protected]