Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5725 Report Date: 18-Jul-95:17:54 Version: ********** Check-in Date: ********** 1.Proposal Title: INTERSTELLAR LEAD -CARRYOVER ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID INTERSTELLAR MEDIUM GO/CAR 4826 Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Prof. L. M. Hobbs CHICAGO, UNIVERSITY OF USA (414) 245-5555 PROFESSOR ------------------------------------------------------------------------------------ 7. Abstract WE PROPOSE TO USE THIS DIRECTOR'S DISCRETIONARY TIME TO SEARCH FOR INTERSTELLAR ABSORPTION BY GASEOUS INTERSTELLAR LEAD IN THE SPECTRUM OF 1 SCO. IN OUR CYCLE 1 DATA FROM PROGRAM 3993, WE HAVE ALREADY SIMILARLY DETECTED INTER- STELLAR TIN TOWARD THE SAME STAR. AT Z=50, TIN IS ONE OF THE HEAVIEST ELEMENTS DETECTED IN THE INTERSTELLAR MEDIUM, AND, AT Z=82, LEAD IS THE HEAVIEST. ON QUITE FIRM GROUNDS, WE EXPECT THE 1433 A LINE OF PB II TO ATTAIN A STRENGTH OF ABOUT 1 MA TOWARD 1 SCO, OR ABOUT 25% OF THAT OF THE SN II 1400 A LINE WHICH WE HAVE PREVIOUSLY DETECTED. SUCH A PB II LINE SHOULD BE DETECTABLE IN THE SINGLE SPECTRAL EXPOSURE WHICH CONSTITUTES THIS PROGRAM. ------------------------------------------------------------------------------------ 8. Scientific Key Words: INTERSTELLAR CLOUDS ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0.95 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5725 PI: Prof. L. M. Hobbs Proposal Title: INTERSTELLAR LEAD -CARRYOVER ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ P.I. L. M. Hobbs CHICAGO, UNIVERSITY OF USA Dr. D. C. Morton HERZBERG INSTITUTE OF CANADA ASTROPHYSICS Dr. L. Spitzer Jr. PRINCETON UNIVERSITY USA Dr. D. E. Welty CHICAGO, UNIVERSITY OF USA Dr. D. G. York CHICAGO, UNIVERSITY OF USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. FOR ONE STAR, ONE GHRS EXPOSURE IS TO BE OBTAINED THROUGH THE LARGE SCIENCE APERTURE IN THE FP-SPLIT MODE, WITH THE ECH-A GRATING. THE 4 SUB-EXPOSURES ARE CENTERED NEAR 1434 A. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. THE PROPOSED SCIENTIFIC PROGRAM CANNOT BE CARRIED OUT WITH ANY OTHER EXISTING TELESCOPE AND SPECTROGRAPH. THE HIGHEST POSSIBLE SPECTRAL RESOLVING POWER AND S/N RATIO ARE REQUIRED TO ACHIEVE A DETECTION OF THE EXPECTED VERY WEAK, NARROW LINE. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. THE EXPOSURE TIME REQURIED FOR THE ONE GHRS EXPOSURE IS GIVEN BELOW IN THE EXPOSURE LOGSHEET. OBSERVED, ABSOLUTE FLUXES MEASURED AT 1400 AND 1450 ANGSTROMS HAVE BEEN PUBLISHED FOR 1 SCO IN THE UV BRIGHT-STAR SPECTROPHOTOMETRIC CATALOGUE OF CATALOGUE OF JAMAR ET AL (1976). THE ABSOLUTE SENSITIVITY OF THE GHRS IS GIVEN IN THE GHRS INSTRUMENT HANDBOOK. THIS COMBINATION ALLOWS STRAIGHTFORWARD ESTIMATES OF THE REQUIRED EXPOSURE TIME. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). EXTENSIVE DATA-ANALYSIS CAPABILITIES WHICH ARE TAILORED PRECISELY FOR THIS KIND OF OBSERVATIONAL DATA AND ITS INTERPRETATION EXIST AT, AND WILL BE MADE AVAILABLE BY, OUR HOME INSTITUTIONS. ------------------------------------------------------------------------------------ 11. Address Information Name: L. M. HOBBS Category: PI Institution: UNIVERSITY OF CHICAGO Address: YERKES OBSERVATORY City: WILLIAMS BAY State: WI Zip Code: 531910258 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5725 [ 3] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 14 HD141637 1 A,110 RA= 15H 47M 57.94S +/- 1950 V= +03 1 V=4.68+/-0.02, TYPE=B2.5V, E(B- SCO 0.01S, 2 V)=0.16 DEC= -25D 36' 03.0" +/- 0.1" 3 F-CONT(1480)=7.27 E-10 4 F-CONT(1600)=5.65 E-10 5 F-CONT(2000)=2.96 E-10 F-CONT(2400)=2.17 E-10 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B 1950.00 -0.0015 +/- 0.0000 -0.0270 +/- 0.0000 0.0050 +/- 0.0050 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5725 [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 306 DEFINE # HRS ACCUM 2.0 ECH-A 1433.9 FP-SPLIT=DSFOUR 1 24.0M # 2 # DDT STEP-PATT=7 Comments: PB II ------------------------------------------------------------------------------------------------------------------------------------ 714.1 HD141637 HRS ACQ 2.0 MIRROR-A1 SEARCH-SIZE=3 1 18S 30 3 1 ONBOARD ACQ FOR BRIGHT=RETURN 714.4 LOCATE=YES SEQ 714.1-714.4 NO GAP CYCLE 4 / 714.1- 714.4 Comments: STEP-TIME = 2 SEC ------------------------------------------------------------------------------------------------------------------------------------ 714.4 USE DDT HD141637 X1.0 300 1 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5725 [ 5] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FP-SPLIT=DSFOUR STEP-PATT=7 SEARCH-SIZE=3 BRIGHT=RETURN LOCATE=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO/CAR ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 0.95 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category INTERSTELLAR MEDIUM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 714.4; SEQ 714.1-714.4 NO GAP; CYCLE 4 / 714.1-714.4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements ECH-A MIRROR-A1 ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD141637 1 SCO ------------------------------------------------------------------------------------------------------------------------------------