Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5677 Report Date: 18-Jul-95:17:50 Version: ********** Check-in Date: ********** 1.Proposal Title: BLUE STRAGGLERS IN M80 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR POPULATIONS GO/CAR 3872 Sub Category GLOBULAR CLUSTERS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Michael M. Shara SPACE TELESCOPE SCIENCE INST USA 410-338-4743 ------------------------------------------------------------------------------------ 7. Abstract We have discovered an extremely large population of blue stragglers (on HST Science Verification focus frames) at the very center of 47 Tucanae. The extraordinarily high surface density we found is in stark contrast with Hesser et al's almost complete lack of detection of blue stragglers further from the core. We are proposing to use the PC to map the distributions of blue stragglers in seven globular clusters of systematically increasing central density. Our goals are to determine and to compare the numbers, mean masses and distributions of the blue stragglers in globulars of widely differing central density. These observational results will be used to test theoretical predictions and numerical simulations of stellar density distributions and stellar collision rates in globular cluster cores. The proposed observations demand high spatial resolution imaging of moderately bright point sources near 3000 Angstroms...exactly what HST does best. Most of the target clusters are in, or close to, HST's Continuous Viewing Zone. Thus the proposed observations can make high efficiency use of HST time. In the event of a serious PC failure, (e.g. worsening contamination for the F284W filter) these observations can be carried out with the F439W filter of the PC, or with the F220W and F150W filters with FOC by doubling the allocated observing time. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 2.29 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5677 PI: Michael M. Shara Proposal Title: BLUE STRAGGLERS IN M80 ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi Michael M. Shara ST SCI USA Francesco F. Paresce ST SCI USA X Georges C. Meylan ST SCI USA X Ivan R. King UC BERKELEY USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. Eleven fields in 4 globular clusters are to be imaged with the PC. Three images, with each of the F336W and the F439W filters, will be obtained to produce color magnitude diagrams to identify blue stragglers. Several frame centers on the more extended clusters are required to reach out several core radii from the globulars' centers. This is needed to obtain the gradient in numbers of blue stragglers. NO PREFLASH IS REQUIRED, the clusters provide it. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. This project demands high angular resolution to separate the blue stragglers from the myriad of red giants, subgiants and main sequence stars near the cores of globular clusters. ------------------------------------------------------------------------------------ 9. Description of previous HST work. P2472 Shara, P.I. and Paresce Co-I Interacting Binary Stars in the Cores of Globular Clusters Six hours of HST/FOC time to search for large-amplitude variables (>0.3 mag) in the globular NGC 6752. Data successfully taken and being analyzed. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). STScI will supply full salaries of Shara and Paresce. The requested salary is to support a Science Data Analyst to assist with the large bulk of data reductions. Our experience is that 2 weeks is required to carefully sum pairs or triples of images, remove cosmic rays, extract and match up catalogs of stars, perform photometry and generate CMDs for a single field. Allowing for a two month training period,vacation,etc, the image reductions should require about 1 year of SDA time. The comparisons between different fields and between different clusters will require at least 4 man-months effort. Finally, the SDA will work for about 8 months with the co-Is on matching the observed blue straggler frequencies and distributions to calculated and simulated cluster core collision rates and straggler formation rates. ------------------------------------------------------------------------------------ 11. Address Information Name: MICHAEL M. SHARA Category: PI Institution: ST SCI Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: 410-338-4743 Telex (or e-mail): 410-338-5090 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5677 [ 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 NGC6093-CORE C,201,910 RA=16H17M02.4S +/-0.1S, 2000 1 V=17.3 +/-0.5,TYPE=F0V M80-CORE DEC=-22D58'35" +/-1.0" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5677 [ 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 DEFINE # WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 900S 100 1 1 CYCLE 4 / 1-3 PCUB GROUP 1-2.3 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 1.1 DEFINE # WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 900S 100 1 1 PCUB ------------------------------------------------------------------------------------------------------------------------------------ 1.2 DEFINE # WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 900S 100 1 1 PCUB ------------------------------------------------------------------------------------------------------------------------------------ 1.3 DEFINE # WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 900S 100 1 1 PCUB ------------------------------------------------------------------------------------------------------------------------------------ 2 DEFINE # WFPC2 IMAGE PC1 F439W CR-SPLIT=NO 1 300S 100 1 1 PCUB ------------------------------------------------------------------------------------------------------------------------------------ 2.1 DEFINE # WFPC2 IMAGE PC1 F439W CR-SPLIT=NO 1 300S 100 1 1 PCUB ------------------------------------------------------------------------------------------------------------------------------------ 2.2 DEFINE # WFPC2 IMAGE PC1 F439W CR-SPLIT=NO 1 300S 100 1 1 PCUB ------------------------------------------------------------------------------------------------------------------------------------ 2.3 DEFINE # WFPC2 IMAGE PC1 F439W CR-SPLIT=NO 1 300S 100 1 1 PCUB ------------------------------------------------------------------------------------------------------------------------------------ 3 USE NGC6093- PCUB CORE ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5677 [ 5] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO/CAR ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 2.29 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR POPULATIONS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category GLOBULAR CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4 / 1-3; GROUP 1-2.3 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W F439W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC6093-CORE M80-CORE ------------------------------------------------------------------------------------------------------------------------------------