Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2693c Report Date: 09-May-96:17:17 Version: ********** Check-in Date: ********** 1.Proposal Title: A SEARCH FOR MASS LOSS FROM TWO RED GIANTS IN NGC 6752 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR ASTROPHYSICS GO Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. A. K. Dupree CFA USA (617) 495-7489 SR. ASTROPHYSICIST ------------------------------------------------------------------------------------ 7. Abstract To reproduce the observed color magnitude diagram of globular clusters with stellar evolution codes, it has been necessary to assume that substantial amounts of mass are lost from metal-poor stars ascending the red giant branch for the first time. Currently however, there is no direct observational detection of mass loss from such stars. We propose to obtain high resolution spectra of the 2795.5 and 2802.7 Mg II (h and k ) lines for two red giants in the globular cluster NGC 6752. The profiles of these well known chromospheric lines can establish the presence of stellar mass loss from and circumstellar material around red giant stars in globular clusters. The High Resolution Spectrograph is the only instrument available that is capable of high resolution ultraviolet spectroscopy of stars as faint as globular cluster red giants. The rate of any mass loss, as well as the outflow velocity, can be derived from fitting the observed Mg II profiles will represent fundamental data necessary for understanding late stages of the evolution of low-mass stars. ------------------------------------------------------------------------------------ 8. Scientific Key Words: GIANT, GLOBULAR CLUSTER, POPULATION II, CHROMOSPHERE, MASS LOSS ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 9.00 par: 0 10. Num targs pri: 2 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2693c PI: Dr. A. K. Dupree Proposal Title: A SEARCH FOR MASS LOSS FROM TWO RED GIANTS IN NGC 6752 ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ P.I. A. K. Dupree CFA USA Lee W. Hartmann CFA USA A. W. Rodgers MT STROMLO & SIDING SPRING AUSTRALIA OBSERVATORIES G. H. Smith STSCI USA Ivan R. King CALIFORNIA, UNIVERSITY OF, USA BERKELEY ------------------------------------------------------------------------------------ 3. Description of proposed observations. With the HRS, we plan to acquire moderate resolution line profiles of the Mg II resonance transition at 2800 angstroms in two red giant stars in the globular cluster NGC 6752. ------------------------------------------------------------------------------------ 11. Address Information Name: A. K. DUPREE Category: PI Institution: SMITHSONIAN INSTITUTION Address: 60 GARDEN STREET City: CAMBRIDGE State: MA Zip Code: 02138 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2693c [ 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| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 A31 STAR; TYPE = K0 III; RA = 19H 11M 11.282S +/- J2000 1 V=10.8 +/-0.2,TYPE=K0 III,E(B- RED GIANT; 0.0075S, 2 V)=0.05 GLOBULAR CLUSTER; LATE DEC = -59D 59' 53.89" +/- B-V = 1.69 TYPE; 0.056", ------------------------------------------------------------------------------------------------------------------------------------ 2 A59 STAR; TYPE = K0 III; RA = 19H 10M 32.312S +/- J2000 1 V=10.9+/-0.2,TYPE=K0 III,E(B- RED GIANT; 0.0075S, 2 V)=0.05 GLOBULAR CLUSTER; LATE DEC = -59D 57' 06.25" +/- B-V = 1.59 TYPE; 0.056", ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2693c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 A31 HRS ACQ 2.0 MIRROR-N2 SEARCH-SIZE=1 1 12.75S 1 CYCLE 1 LOCATE=YES ONBOARD ACQ FOR 2, 3 DARK TIME Comments: STEP-TIME = 12.75 ------------------------------------------------------------------------------------------------------------------------------------ 2 A31 HRS IMAGE 2.0 MIRROR-N2 NX=16 1 1792.S 1 CYCLE 1 NY=16 DARK TIME DELTA-X=4 DELTA-Y=4 Comments: STEP-TIME = 7.0 ------------------------------------------------------------------------------------------------------------------------------------ 3 A31 HRS ACCUM 2.0 G270M 2798.6 STEP-PATT=5 15 15M 1 CYCLE 1 FP-SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ 4 A59 HRS ACQ 2.0 MIRROR-N2 SEARCH-SIZE=1 1 12.75S 1 CYCLE 1 LOCATE=YES ONBOARD ACQ FOR 5, 6 DARK TIME Comments: STEP-TIME = 12.75 ------------------------------------------------------------------------------------------------------------------------------------ 5 A59 HRS IMAGE 2.0 MIRROR-N2 NX=16 1 1792.S 1 CYCLE 1 NY=16 DARK TIME DELTA-X=4 DELTA-Y=4 Comments: STEP-TIME = 7.0 ------------------------------------------------------------------------------------------------------------------------------------ 6 A59 HRS ACCUM 2.0 G270M 2798.6 STEP-PATT=5 16 15M 1 CYCLE 1 FP-SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2693c [ 5] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ IMAGE ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SEARCH-SIZE LOCATE=YES NX NY DELTA-X DELTA-Y STEP-PATT FP-SPLIT ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 9.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR ASTROPHYSICS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 1; ONBOARD ACQ FOR 2,3; DARK TIME CYCLE 1 ONBOARD ACQ FOR 5,6; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G270M ------------------------------------------------------------------------------------------------------------------------------------ Target Names A31 A59 ------------------------------------------------------------------------------------------------------------------------------------