Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3897c Report Date: 09-May-96:18:55 Version: ********** Check-in Date: ********** 1.Proposal Title: SPECTROPHOTOMETRY OF COOL WHITE DWARFS -- REPEAT FOR HOPR#0003 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR ASTROPHYSICS RPT/FOS 1050 Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Prof. J. roger P Angel UNIVERSITY OF ARIZONA USA 602-621-6541 PROF. OF ASTRONOMY ------------------------------------------------------------------------------------ 7. Abstract Ultraviolet spectrophotometry will be used to determine whether the ultraviolet blanketing of the coolest DA, DC and DK degenerate stars differ due to the presence of molecular hydrogen and/or heavy metallic elements and/or carbon and whether the coolest DC-DK stars have hydrogen-rich atmospheres. The second question may hold implications for the apparent "cut-off" in the white dwarf luminosity function at Log L/L(sun) = -4, the disk star formation history and age. ------------------------------------------------------------------------------------ 8. Scientific Key Words: COOL WHITE DWARFS ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 3.80 par: 0 10. Num targs pri: 3 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3897c PI: Prof. J. roger P Angel Proposal Title: SPECTROPHOTOMETRY OF COOL WHITE DWARFS -- REPEAT FOR HOPR#0003 ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Dr. Edward Beaver UC, SAN DIEGO USA Dr. E. Margaret Burbidge UC, SAN DIEGO USA Dr. Bruce Margon UNIVERSITY OF WASHINGTON USA Dr. J. Roger P Angel UNIVERSITY OF ARIZONA USA Dr. Holland C Ford JOHNS HOPKINS UNIVERSITY USA Dr. Frank Bartko MARTIN MARIETTA CORPORATION USA Dr. Arthur F Davidsen JOHNS HOPKINS UNIVERSITY USA Dr. Richard J Harms APPLIED RESEARCH CORPORATION USA Dr. Ralph Bohlin SPACE TELESCOPE SCIENCE USA INSTITUTE ------------------------------------------------------------------------------------ 3. Description of proposed observations. Three stars will be observed spectrophotometrically with the FOS. Targets stars should all be bright enough to be in the Guide Star Catalog. Catalog position will need to be adjusted to epoch of observation because of significant proper motion. The proper motions on the forms were taken from LHS Catalogue-Second Edition by William J. Layten, Univ. of Minn., 1979. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Ultraviolet spectrophotometry is required below 3000A. IUE is not sensitive enough. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. The SV prerequisite programs for all FOS observations in this program are: Prop ID 2195 FOS Target Acquisition Tests All observations Prop ID 1317 Int./Ext. Wavelength Offsets 1st target Prop ID 1318 Spectral Flat Fields 1st target Prop ID 1320 Absolute Spectrophotometry 1st visit of bright targets ------------------------------------------------------------------------------------ 13. Ultraviolet spectrophotometry will be used to determine whether the ultraviolet blanketing of the coolest DA, DC and DK degenerate stars differ due to the presence of molecular hydrogen and/or heavy metallic elements and/or carbon and whether the coolest DC-DK stars have hydrogen-rich atmospheres. Three objects are to be studied, LP 658-2, LHS 1126 and BPM 4729. ------------------------------------------------------------------------------------ 11. Address Information Name: RICHARD ALLEN Category: Institution: STEWARD OBSERVATORY Address: UNIVERSITY OF ARIZONA City: TUCSON State: AZ Zip Code: 85721 Country: USA Telephone: 602-621-7661 Telex (or e-mail): 467175 ------------------------------------------------------------------------------------ Page 3 Name: J. ROGER P ANGEL Category: PI Institution: STEWARD OBSERVATORY Address: UNIVERSITY OF ARIZONA City: TUCSON State: AZ Zip Code: 85721 Country: USA Telephone: 602-621-6541 Telex (or e-mail): 467175 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 3897c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 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| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 BPM4729 WHITE DWARF RA=7H 53M 06.08S +/- 1", 2000 1 V=14.09 +/- 0.20 DEC=-67D 47'18.9" +/- 1", PLATE-ID=01YR ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3897c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 BPM4729 FOS/BL ACQ/ 4.3 MIRROR BRIGHT=720000 1 11S 3 CYCLE 1 / 1-4 BINARY SEQ 1-4 NO GAP ONBOARD ACQ FOR 2- 4 ------------------------------------------------------------------------------------------------------------------------------------ 2 ^ ^ ACCUM ^ G400H 3250- ^ 300S ^ 4831 ------------------------------------------------------------------------------------------------------------------------------------ 3 ^ ^ ^ ^ G270H 2230- ^ 1200S ^ 3309 ------------------------------------------------------------------------------------------------------------------------------------ 4 ^ ^ ^ ^ G190H 1600- STEP-TIME=0.05 ^ 1500S ^ 2300 Comments: REJLIM=10 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3897c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ^ ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/BINARY ACCUM ^ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BRIGHT STEP-TIME=0.05 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for RPT/FOS ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 3.80 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR ASTROPHYSICS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 1 / 1-4; SEQ 1-4 NO GAP; ONBOARD ACQ FOR 2-4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G400H G270H G190H ------------------------------------------------------------------------------------------------------------------------------------ Target Names BPM4729 ------------------------------------------------------------------------------------------------------------------------------------