SIMPLE = T / Standard FITS format BITPIX = 8 / Character Information NAXIS = 0 / No image data array present EXTEND = T / Extension exists FILETYPE= 'REV_1_1 ' / Indicates file type ORIGIN = 'ST ScI ' / Space Telescope Science Institute DATE = '01/09/89' / Date of issue (dd/mm/yy) COMMENT THE GUIDE STAR CATALOG COMMENT COMMENT An all-sky astrometric and photometric catalog COMMENT prepared for the operation of the Hubble Space COMMENT Telescope. COMMENT COMMENT Copyright, 1992, Association of Universities COMMENT for Research in Astronomy, Inc. COMMENT COMMENT This file contains data for one of the supporting tables for the GuideCOMMENT Star Catalog (GSC). Additional information on the GSC may be found inCOMMENT accompanying scientific publications as well as in comments and tablesCOMMENT elsewhere on this set of volumes. COMMENT COMMENT The Guide Star Catalog (GSC) was prepared by the Space Telescope ScienceCOMMENT Institute (ST ScI), 3700 San Martin Drive, Baltimore, MD 21218, USA.COMMENT ST ScI is operated by the Association of Universities for Research inCOMMENT Astronomy, Inc. (AURA), under contract with the National Aeronautics andCOMMENT Space Administration (NASA). COMMENT COMMENT COMMENT File REV_1_1 COMMENT Version 1.1 Revisions COMMENT COMMENT This table contains text (in 80 column format) summarizing the revisionsCOMMENT to the Guide Star Catalog that were carried out for this version. END XTENSION= 'TABLE ' / Table Extension BITPIX = 8 / Character Information NAXIS = 2 / Two-dimensional table NAXIS1 = 80 / Number of characters per line NAXIS2 = 560 / Number of rows PCOUNT = 0 / No Random Parameters GCOUNT = 1 / Only one group TFIELDS = 1 / One field per row EXTNAME = 'REV_1_1 ' / Generic Comments EXTVER = 1 / Integer Version Number TTYPE1 = 'TEXT ' / Free text TBCOL1 = 1 / Start in column 1 TFORM1 = 'A80 ' / 80 Character Field END THE GUIDE STAR CATALOG, Version 1.1 An all-sky astrometric and photometric catalog to support the operation of the Hubble Space Telescope Copyright 1992, Association of Universities for Research in Astronomy, Inc. I. OVERVIEW The file, COMMENTS.TBL;1, which contains explanatory text for the originalversion of the Guide Star Catalog (GSC 1.0), is distributed unchanged on thisdisc. The present file, REV_1_1.TBL;1, supplements the thirteen supporting filesissued with GSC 1.0 by explaining the additions and corrections made therein toproduce the present update, GSC 1.1. The production of GSC 1.0 is described in Lasker et al. (1990); Russell et al.(1990); and Jenkner et al. (1990), hereafter referred to as Papers I, II, andIII. Photometry is available in the natural systems defined by the individual platesin the GSC collection (generally J or V), and the calibrations are done using B,V standards from the Guide Star Photometric Catalog (Lasker, Sturch, et al.,1988). In Paper II the overall quality of the photometry near the standard stars wasestimated from the fits and other tests to be 0.15 mag (one sigma, averaged overall plates), while the quality far from the sequences was estimated from theall-sky plate-to-plate agreement and from comparisons with independentphotometric surveys to be about 0.3 mag (one sigma), with about 10% of theerrors being greater than 0.5 mag. Additionally, Ratnatunga's (1990) comparisonof the GSC against totally independent J-band photographic photometry for threesouthern fields (20 sq deg area) in the range 12.5 < J < 15.5 shows agreement atthe 0.1-0.2 mag level. Astrometry, at equinox J2000, is available at the epochs of the individualplates used in the GSC; and the reductions to the reference catalogs (AGK3,SAOC, or CPC, depending on the declination zone) use third order expansions ofthe modeled plate and telescope effects. The fits to the reference catalogs liein the range 0.5" to 0.9", and most of this is attributable to errors in thereference catalogs, to centroiding errors on the relatively large images of thereference stars, and to unmodeled astrometric effects. Paper II reported estimates of the overall external astrometric error, producedby comparisons of independently measured positions, in the range 0.2" to 0.8"(per coordinate), depending on the areas of the plate and the sky. Then from amore extensive analysis against the Carlsberg Automatic Meridian Circle data,Taff et al. (1990) found that GSC absolute positional errors from plate centerto edge vary from 0.5" to 1.1" in the north and from 1.0" to 1.6" in the southand that relative errors at half-degree separations range from 0.33" to 0.76"depending upon hemisphere and magnitude. Generalizations to the GSC object classification scheme have been made (cfSections II and III), such that the complete list of classification codes now isas follows: -------------------------------------------------------------------------------- Table I. Classification Codes 0 - star 1 - galaxy 2 - blend or member of incorrectly resolved blend. 3 - non-star 5 - potential artifact (Note that code 1 is used only for a few hand-entered errata; galaxies successfully processed by the software have a classi- fication of 3 [non-stellar]. Also code 4 is never used.) -------------------------------------------------------------------------------- Even as GSC 1.0 was being published, the possibility of an ongoing programresponding to opportunities for improving the object identification and thecalibration, as well as for incorporating errata was recognized. The presentupdate addresses some of these opportunities; future plans for GSC maintenanceinclude an astrometric recalibration (cf., Taff, Lattanzi, and Bucciarelli1990), and investigation of erroneous double entries that may exist for V > 7.5(see Section III). Among the primary authors of the GSC 1.0 and the associated systems, thescientific responsibilities were divided as follows: Helmut Jenkner, systemcoordination and overall design; Barry M. Lasker, astrophysics and photometry;Brian J. McLean, algorithmic analysis and systems development; Jane L.Russell, astrometry; Michael M. Shara, system management; and Conrad R.Sturch, production management and quality control. GSC 1.1 analysis andproduction were performed primarily by Jesse B. Doggett, Daniel Egret, Brian J.McLean, and Conrad R. Sturch. Helmut Jenkner is on assignment from the European Space Agency; Jane L. Russellis currently affiliated with the Applied Research Corporation, Landover, MD; andConrad R. Sturch is with the Astronomy Programs, Computer Sciences Corporationat Space Telescope Science Institute. Daniel Egret is affiliated withObservatoire de Strasbourg, France. II. ADDITIONS AND CORRECTIONS RELATED TO THE BRIGHT STARS On well-exposed Schmidt plates the brighter stars are heavily exposed andcharacterized by a number of defects which give rise to image-processingartifacts and cataloging errors. Considering a progression to brightermagnitudes, one first encounters significant diffraction spikes around V = 11(all magnitudes in this introduction are very approximate and depend on thedetails of the individual exposures), then around V = 9 reflections from thefilter begin to form a rather dense disk about the stellar images. By V = 7.5the images have very ugly halos and corrector ghosts and severe measurementproblems are beginning to be present. A detailed discussion of image growth onSchmidt plates, together with examples, may be found in the UK Schmidt Handbook(Section 5.5.6, Tritton 1983). The following defects in GSC 1.0 are directlyattributable to these image characteristics: - False entries, where the blend resolver has interpreted noise on diffraction spikes, corrector ghosts, or halos as valid astronomical images. - Very large astrometric errors, where the centroider has been confused by one of the ghosts or halos. - At sufficiently bright magnitudes the burnt out area around the star is not processed. This results in a double incompleteness, first that the bright object is missed, and second that all fainter objects in the excluded area are missed. At the same time, two other bright-star errors need to be considered: - GSC 1.0 stars with V < ~9, the bright limit of the photometric reference stars, were calibrated in extrapolation. Because the quality of such an extrapolation is poor, entries for these stars often have errors as large as several magnitudes. - Where the same objects appear on overlapping Schmidt plates, the GSC contains multiple entries, with each entry having a unique plate identifier but the same name (see Paper III for details). The object- matching underlying the naming is based primarily on position, and so is unreliable for those objects in which the centroider has been confused by ghosts and halos. This results in the appearance of a number of false doubles. A. Corrections Based on the TYCHO Input Catalog The starting point in addressing these points is a catalog that is complete fromthe brightest star to well beyond the limit from which the GSC becomes reliable,i.e., about V = 7.5. Because the Tycho Input Catalog (TIC, Egret et al., 1992)is based on a combination of the GSC, for the fainter objects, and the HipparcosINCA Data Base (Turon et al., 1991; Turon et al., 1992; Jahreiss et al., 1992;Grenon et al., 1992), for the brighter, it is the natural choice for thiseffort. To make the GSC complete at bright magnitudes, all TIC stars with V < 8.0 whichoriginated from the INCA Data Base and which had no GSC counterparts wereinserted into GSC 1.1. (In a later review of this procedure, inspection of 36"squares centered on positions of SAO Catalog stars with V < 7.0, identified TICentries inserted near the positions of GSC entries of comparable magnitudes. Inmost of these cases the GSC and TIC entry had position differences between 5"and 12" and magnitude differences less than 1.5 mag. The TIC entries wereretained and the GSC entries, a total of 250, were deleted.) Then, to eliminatethe photometric and astrometric errors associated with the brighter GSC stars,the 20,265 GSC 1.0 entries matching INCA stars brighter than V = 7.5 (or B = 8.0for those lacking V magnitudes) were replaced in GSC 1.1 by the INCA data. Thereplacement limit of V = 7.5 was chosen to preserve the original GSC entries ofall objects that were used in the astrometric calibration of the plates. GSC1.1 entries based on the TIC are identified with the plate designation +056. Naming errors associated with the brighter stars were investigated by searchingthe resultant GSC for unmatched objects within 20" of those TIC entries whichare based on INCA data. Visual inspection of the scans of a representativesample of these indicated that the failure to match images of the same object ondifferent plates was primarily due to poor centroiding of the saturated images(e.g., because of displaced filter ghosts) and that the frequency ofcorresponding naming errors increases with the size of the over-exposedbright-star images. For the 94 shorter exposures (the 4 minute XV plates; see Paper I, Table III fora list of plates) only 14 unmatched objects were found. For the 610 N plateswith 20-minute exposures, a total of 334 unmatched objects were indentified.Moreover, the larger part of the naming errors due to matching failures, 1362,occurred on the 800 S plates which had exposure times of 60-90 minutes. Most ofthe unmatched GSC objects were within 5" of the INCA star, but positiondifferences as large as 19" were found and verified. A total of 1720 namingerrors, including 10 from southern bright star regions covered by astrographplates (see below), were deleted from GSC 1.1. Possible naming errors for stars fainter than V=7.0, especially those from Splates, will be investigated following planned astrometric recalibration of theGSC. B. Artifacts Near the Bright Stars For the S plates, in areas around stars with V < 3, visual inspection toidentify and delete artifacts was a part of the GSC 1.0 processing. However, asthe effort to extend such inspection to fainter magnitudes would have beenprohibitive and as a concern with artifacts near diffraction spikes exists forstars as faint as V = 8 on the S plates, a less perfect but fully automatedapproach was implemented to identify potential artifacts near the approximately50,000 stars with 3 < V < 9 on the SERC-J plates. The search is conducted within horizontally and vertically oriented elongatedrectangles centered on each such star. The shapes of these figures wereobtained by visual inspection, maximizing the number of artifacts and minimizingthe number of astronomical objects identified. The width, allowing formisalignment of spikes, was set at 8 pixels; the length taken as 10**(3.42 -0.24 J). In GSC 1.1, all potential artifacts identified by this rectangulararea criterion are given a classification of 5 (regardless of their GSC 1.0classification), with the exception being that, for fields on several plates,candidates were considered to be artifacts if they appeared on at most twoplates. From a visual control study of the Schmidt images for 1333 GSC objects in thefields of 241 bright stars with 3 < V < 7, the following statistics result:approximately 98% of the artifacts are correctly classified as such, but 64% ofthe stars in the vicinity of the diffraction spikes are misclassified asartifacts. As a result, approximately 42% of the entries classified asartifacts are actually astronomical objects. C. Completion of Areas around Bright Stars GSC 1.1 contains entries from supplemental astrograph plates covering smallareas around southern stars brighter the V = 3. These were needed to fill inthe missing GSC areas obscured by the over exposed images of bright stars on theSERC-J (S) plates. This was not a problem for the northern Quick-V (N) surveyplates or the southern supplemental short V (XV) plates. The astrograph plateswere taken with the twin astrograph at the Black Birch Observatory in Blenheim,New Zealand and with the Gran Prisma Objectif (GPO) telescope at the EuropeanSouthern Observatory on La Silla. Black Birch and GPO plates are designated with prefixes XB and XG, respectively.The field number is that of the standard survey plate with the nearest center,except that, when more than one special plate is associated with a standardfield, a one digit suffix (1, 2, ...) is appended to the plate number to provideuniqueness. The XB plates are 8 x 10 inches with a scale of 100.2"/mm; blue and yellowbandpasses were used. The blue bandpass is defined by the blue objective and103aO emulsion; and the yellow bandpass, by the yellow objective, 103aGemulsion, and GG495 filter. The exposure times were 20 minutes. The GPO plates were taken through a yellow objective with IIaD emulsion andGG495 filter. The plates are 10 inches square with a scale of 51.5"/mm. Theexposure times were 15 minutes. These plates were scanned and processed in the same ways as the standard surveyplates, except for the photometric and astrometric calibrations. For most XGplates and a few XB plates, GSPC photometric sequences and/or standardastrometric reference stars were unavailable within the plate boundaries. Inthese cases calibrators were selected from GSC entries from the overlapping Ssurvey plate. The resulting magnitudes are in the J bandpass of the S plate andthe resulting positions are in the local reference frame of the S plate. (Thelarge areas covered by the XB plates generally contained standard calibrators.Usually the entire area of the XB plate was inventoried and calibrated with thestandard calibrators; however, only the central two-degree square region of theinventory was merged into the GSC.) GSC bandpass codes for GSC 1.1 plates are given in the Table II below.Asterisks indicate those bandpass codes where photometric calibrators wereselected from the GSC. -------------------------------------------------------------------------------- Table II. Bandpass Codes and Calibration Exceptions Bandpass Plate Emulsion, Filter Code Prefix 0 S - IIIaJ + GG395 1 N - IIaD + W12 6 N - IIaD + GG495 8 XE - 103aE + Red Plexiglass 10* XG - yellow objective + IIaD + GG495 11 XB - blue objective +103aO 12* XB - blue objective +103aO 13 XB - yellow objective + 103aG + GG495 14* XB - yellow objective + 103aG + GG495 18 XN - IIIaJ + GG385 * Calibrated with the GSC. -------------------------------------------------------------------------------- Table III, in Appendix A, contains a list of all astrograph plates that wereincorporated into the GSSS for which scans and astrometric plate calibrationsare available. GSC 1.1 contains entries from most of these plates. III. CLOSE PAIRS AND OTHER ERRATA GSC 1.0 contains many pairs of objects (from single plates) with separationssignificantly smaller than the expected resolution of the catalog. Garnavich(1991) studied the resolution limit for the N plates and concluded that the GSCresolves images separated by more than 12" for stars with 8.0 < V < 14.0, while,even for the faintest primary members of pairs, the GSC is unlikely to resolveand correctly classify pairs of stars closer than 10". From further analysis ofa small sample of GSC pairs with separation less than 20" on N, S and XV plates,we conclude that such entries generally are real pairs. Processing of pairsnear the resolution limit often resulted in shifting the positions of bothmembers (or more rarely the position of one member) toward the centroid of theblend. This is generally the case for all single-plate pairs with GSCseparation less than 5" (three pixels in the digital image). Depending on theplate type, brighter pairs also are affected at larger separations. To assist the user in identifying probable pairs with underestimated angularseparations, both members of all pairs in GSC 1.1 with separation less than 5",originating from single survey plates and excluding TIC entries, are givenclassifications of 2 (blend). Pairs with separations of 5 to 20" are also soclassified if their separations, r, in arc-seconds, are within the limits, r < 29 - 2 V (N plates), r < 33 - 2 J (S plates), r < 25 - 2 V (XV plates), where V and J are the GSC magnitudes of the brighter member in the platebandpass. Reclassifications were made for 9307 pairs from N plates, 57142 pairsfrom S plates, and 3272 pairs from XV plates. Specific errors in GSC 1.0 have been reported by several astronomers oridentified through analysis of HST GS Problem Reports. Some of these errorshave been corrected or identified in general revisions described above. A few,including mismatches, plate flaws, misclassifications, and multiple stars, havebeen individually corrected in GSC 1.1. The photometric error parameter in GSC 1.1 is now correctly described byequation (3) in Paper II; i.e., the erratum of footnote 5 therein is no longerpertinent. Appendix A: Astrograph Plates in the GSSS Table III lists all GSSS astrograph plates for which scans and astrometric platecalibrations are available. The first two columns give the GSSS Plate Numberand the Field Number, which except for the prefix is same field number as thatof the S plate with the nearest plate center. The third column gives the GSSSNumber for the S plate if astrometric calibrators from the S plate were used forcalibration of the astrograph plate. The fourth and fifth columns contain GSSSPlate and Field Numbers for the rest of the GSSS astrograph plates, none ofwhich were calibrated from S plate astrometric data. -------------------------------------------------------------------------------- Table III. Astrograph Plates with Scans and Astrometric Calibrations GSSS Field Calibration | GSSS Field No. No. Plate | No. No. 0671 XG288 02IR | 06IB XB651 0678 XG012 00OO | 06IC XB725 067B XB186 02EB | 06ID XB800 068N XB668 ---- | 06IE XB517 06EH XG152 025D | 06IZ XB889 06EI XG469 00GD | 06J0 XB146 06EK XG619 02NG | 06J1 XB069 06EL XG768 02NB | 06J3 XB658 06EM XG840 0084 | 06J6 XB459 06EO XG312 02EZ | 06J8 XB815 06EP XG260 02FD | 06J9 XB672 06EQ XG126 007J | 06JA XB404 06ER XG696 00DX | 06JB XB290 06ES XG719 006N | 06LA XB766 06EU XG133 02EW | 06LB XB695 06EV XG384 02C5 | 06LC XB627 06G2 XB031 ---- | 06LD XB258 06G3 XB573 ---- | 06LE XB114 06G4 XB061 ---- | 06LF XB207 06G5 XB171 ---- | 06M4 XB367 06GB XB100 ---- | 06M6 XB425 06GC XB124 ---- | 06M7 XB161 06GD XB165 ---- | 06M8 XB427 06GE XB166 ---- | 06M9 XB554 06GF XB707 ---- | 06MA XB839 06GH XB172 ---- | 06MB XB5541 06H2 XB215 ---- | 06MC XB363 06H3 XB506 ---- | 06MD XB556 06H5 XB515 ---- | 06ME XB491 06H6 XB217 01F6 | 06MF XB428 06H7 XB064 ---- | 06MG XB4911 06H8 XB271 ---- | 06MH XB494 06H9 XB327 ---- | 08TZ XB134 06HA XB273 ---- | 08U0 XB584 06HB XB2731 ---- | 08U1 XB5841 06HD XB218 03C3 | 08U2 XB729 06HE XB861 ---- | 08U3 XB3341 06HG XB382 ---- | 08U4 XB395 ------------------------------------------------------------------------------ IV. REFERENCES Egret, D., Didelon, P., McLean, B. J., Russell, J. L., and Turon, C.: Tycho Input Catalog - Cross-matching the Guide Star Catalog with the Hipparcos INCA Data Base; Astron. Astrophys., 258, 217-212 (1992). Garnavich, P.: The Stellar Angular Correlation: Clues to Wide Binary Star Properties; dissertation, University of Washington (1991). Grenon, M., Mermilliod, M., Mermilliod, J., C.: The Hipparcos Input Catalogue. III. Photometry; Astron. Astrophys., 258, 88-93 (1992). Jahreiss, H., Requieme, Y., Argue, A. N., Dommanget, J., Rousseau, M., Lederle, T., Le Poole, R. S., Mazurier, J. M., Morrison, L. V., Nys, O., Penston, M. J., Perie, J. P., Prevot, L., Tucholke, H. J., de Vegt, C.: The Hipparcos Input Catalogue. II. Astrometric Data; Astron. Astrophys., 258, 82-87 (1992). Jenkner, H., Lasker, B. M., Sturch, C. R., McLean, B. J., Shara, M. M. Russell, J. L.: The Guide Star Catalog. III. Production, Database Organization, and Population Statistics; Astronomical, J., 99, 2081-2154 (1990). Lasker, B. M., Sturch, C. R. et al.: The Guide Star Photometric Catalog. I.; Astrophysical J. Suppl., 68, 1-90 (1988). Lasker, B. M., Sturch, C. R., McLean, B. J., Russell, J. L., Jenkner, H., Shara, M. M.: The Guide Star Catalog. I. Astronomical and Algorithmic Foundations; Astronomical, J., 99, 2019-2058 (1990). Ratnatunga, K. U.: Comparison of GSC Photometry in Three Southern Fields; Astronomical J., 100, 280-290 (1990). Russell, J. L., Lasker, B. M., McLean, B. J., Sturch, C. R., Jenkner, H.: The Guide Star Catalog. II. Photometric and Astrometric Calibrations; Astronomical J., 99, 2059-2081 (1990). Taff, L. G., Lattanzi, M. G., Bucciarelli, B.: Two Successful Techniques for Schmidt Plate Astrometry; Astrophysical J., 358, 359-369 (1990). Taff, L. G., Lattanzi, M. G., Bucciarelli, B., Gilmozzi, R., McLean, B. J., Jenkner, H., Laidler, V. G., Lasker, B. M., Shara, M. M., Sturch, C. R.: Some Comments on the Astrometric Properties of the Guide Star Catalog; Astrophysical J., 353, L45-L48 (1990). Tritton, S. editor, The UK Schmidt Telescope Handbook (Royal Observatory, Edinburgh, 1983). Turon, C., Arenou, F., Baylac, M.-O., Boumghar, D., Crifo, F., Gomez, A., Marouard, M., Mekkas, M., Morin, D., Sellier, A.: The HIPPARCOS INCA Database; in Databases & On-line Data in Astronomy, ed. M. A. Albrecht and D. Egret (Dordrecht: Kluwer Academic Publishers), 67-78 (1991). Turon, C., Gomez, A., Crifo, F., Creze, M., Perryman, M. A. C., Morin, D., Arenou, F., Nicolet, B., Chareton, M., Egret, D.: The Hipparcos Input Catalogue. I. Star Selection; Astron. Astrophys., 258, 74-81 (1992). V. ACKNOWLEDGEMENTS Special thanks are due to Riccardo Giacconi, Director of the Space TelescopeScience Institute, for his vision and continuing support of this project. The Guide Star Catalog is partially based on data obtained at PalomarObservatory, operated by the California Institute of Technology; at the U.K.Schmidt Telescope, operated by the U.K. Science and Engineering ResearchCouncil and by the Anglo-Australian Observatory; at the Cerro TololoInter-American Observatory and the Sacramento Peak Observatory, both operated bythe Association of Universities for Research in Astronomy, Inc., under contractto the National Science Foundation; at the Mount Lemmon Observatory, operated bythe University of Arizona; at the Black Birch Observatory, Blenheim, NewZealand; and at the European Southern Observatory. The primary authors would like to thank the large number of persons who havepartaken in the Guide Star Selection System and the Guide Star Catalog develop-ments over the past years. Specifically, the contributions of the followinggroups and individuals are gratefully acknowledged: o members of ST ScI and the astronomical community: William van Altena, Christopher Anderson, John Bahcall, Heinrich Eichhorn, William Fastie, Robert Harrington, Mark Johnston, Dennis Kelly, Daniel Klinglesmith III, David Koo, Jin-Fuw Lee, Harvey MacGillivray, Jaylee Mead, Ray Soneira, Kaj Strand, Archibald Warnock, Richard White, and Carol Williams; o students and assistants contributing scientific support: John Blondin, Kashif Chaudhry, Peter Garnavich, Terry Gerard, Sarah LeBrun, Amy Mossman, Dale Ostlie, and James Scott; o the Guide Star Operations Group: Deborah Kenny, Victoria Laidler, Ray Lucas, James Phillips, Daniel Rehner, Elizabeth Siciliano, Caroline Simpson, Denise Tullos, and William Workman; o the Guide Star Selection System software team: David Allen, John Baum, John Baumert, Gerald Blackwell, Joseph Buckley, Napolia Dunn, Aaron Dutton, Yuri Frankel, Joseph Harrison, Christopher Harvel, Adolph Hendrickson, Robin Lerner, Steven McLaughlin, Ed Medeiros, Beverly Owens, Joseph Pollizzi, Paul Rigterink, Donald Rosenthal, Bernie Simon, Allen Wentink, Daniel Wilson, Barry Wishner, and Gerald Zavage; o software and hardware consultants: Norman Crowfoot, Michael Dearing, Anthony Hewitt, Robert Nagel, Peter Shames, and Manfred Stoll; o software configuration managers: Warren King and Keith McQuay; o computer system managers: Thomas Comeau, Marian Iannuzzi, Greg McLeskey, Don Stevens-Rayburn, and William Whitman; o the engineering and electronics support group: Joseph Assanah, Marc Damashek, Robert Denman, Anatoly Evzerov, James Kinsey, Donald Mohidan, and Ronald Russell; o advisers in the areas of FITS and optical disk archive: Robert Hanisch, Zoltan Levay, and Thomas McGlynn; o for pre-mastering the CD-ROMs: Ian Evans; o for photographic and graphics support: John Bedke, Dana Berry, Dave Paradise, Carl Schuetz, and Skip Westphal; o for publication support: Ronald Meyers, Robert Miller, Sharon Toolan, and Dorothy Whitman; o for secretarial support: Barbara Larkin, Teresa Schiano, and Patty Trovinger; o for project and ST ScI management: Bruce Gillespie, Dennis Kilroy, Robert Milkey, Ethan Schreier, Peter Simmons, Adrienne Timothy, and Chi-Chao Wu. o by contributing to the GSC 1.0 error discussion or by reporting specific errors in GSC 1.0: Beatrice Bucciarelli, Daniel Egret, Holland Ford, Peter Garnavich, Roberto Gilmozzi, Roberta Humphreys, Mario Lattanzi, William Owen, Barry Rappa- port, Kavan Ratnatunga, Larry Taff, Patrick Wallace, Fred Walter, and Archibald Warnock; o for providing astrograph plates for southern bright stars: Geoffrey Douglass, Robert Harrington, G. Monderen, and Otto Richter; o and by collaboration in merging INCA data into GSC 1.1: Daniel Egret and the HIPPARCOS INCA and Tycho groups.
