Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3565c Report Date: 09-May-96:18:42 Version: ********** Check-in Date: ********** 1.Proposal Title: THE STELLAR DENSITY DISTRIBUTIONS IN THE CENTERS OF GALACTIC GLOBULAR CLUSTERS: CYCLE 2 AUGMENTATION ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR POPULATIONS AUG/OS 1019 Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. John N. Bahcall INSTITUTE FOR ADVANCED STUDY USA (609) 734-8054 DR. JOHN N. BAHCALL ------------------------------------------------------------------------------------ 7. Abstract Short exposures will be made of all galactic globular clusters with distance moduli less than 15.5 mag and galactic latitude above or below 15 degrees. A search will be made for cusps in the stellar density distributions and the colors will be measured for the brightest stars in the cores of the clusters. ST observations are required in order to reach the innermost regions of the clusters with sufficient resolution to separate individual stars. ------------------------------------------------------------------------------------ 8. Scientific Key Words: GLOBULAR CLUSTER, POPULATION II, BLACK HOLE ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0.25 par: 0 10. Num targs pri: 20 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3565c PI: Dr. John N. Bahcall Proposal Title: THE STELLAR DENSITY DISTRIBUTIONS IN THE CENTERS OF GALACTIC GLOBULAR CLUSTERS: CYCLE 2 AUGMENTATION ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ John N. Bahcall INSTITUTE FOR ADVANCED STUDY USA Neta A. Bahcall SPACE TELESCOPE SCIENCE USA INSTITUTE ------------------------------------------------------------------------------------ 3. Description of proposed observations. Two exposures will be taken for each object. They need not be consecutive, but the telescope roll angle should be the same for both exposures. This series of exposures will give both colors (V and I) and number densities for the brightest stars in the central regions of the globular clusters. Cycle 1 (SV: 1-6 months) plus Cycle 2 (7-18 months) = Exposures 1-40. The target position should be placed at the center of one CCD, immaterial which one. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. ST observations are required in order to resolve individual stars in the cores of the globular clusters in sufficient numbers to permit a determination of the stellar density law. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. The telescope roll angle should be the same for both exposures on a given cluster, although the two exposures on a cluster need not be consecutive. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Data reduction and analysis will be performed at both the Institute for Advanced Study and at STScI. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. The target position should be placed at the center of one CCD, immaterial which one. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Computing support and research associates will be available at both IAS and STScI as required by the science. ------------------------------------------------------------------------------------ 13. Short exposures will be made of all galactic globular clusters with distance moduli less than 15.5 mag and galactic latitude above 15 degrees. A search will be made for cusps in the stellar density distributions and the colors will be measured for the brightest stars in the cores of the clusters. Short exposures will be made of all galactic globular clusters with distance moduli less than 15.5 mag, estimated core radii less than 1 arc minute, and galactic latitude above 15 degrees. We will search for a cusp in the stellar density distribution. ------------------------------------------------------------------------------------ 11. Address Information Page 3 Name: JOHN N. BAHCALL Category: PI Institution: INSTITUTE FOR ADVANCED STUDY Address: OLDEN LANE City: PRINCETON State: NJ Zip Code: 08540 Country: USA Telephone: (609) 734-8054 Telex (or e-mail): 837680 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 3565c [ 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 NGC5272 M3 C, 201 RA = 13H 39M 52.94S +/- 1950 1 SURF(V) = 16.31 +/- 0.2 0.1S, DEC = +28D 37' 37.9" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6093 M80 C, 201 RA = 16H 14M 03.37S +/- 1950 1 SURF(V) = 14.40 +/- 0.2 0.1S, DEC = -22D 51' 09.2" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC6171 M107 C, 201 RA = 16H 29M 43.85S +/- 1950 1 SURF(V) = 18.93 +/- 0.2 0.1S, DEC = -12D 56' 54.1" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6254 M10 C, 201 RA = 16H 54M 30.65S +/- 1950 1 SURF(V) = 17.61 +/- 0.2 0.1S, DEC = -04D 01' 20.6" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC7089 M2 C, 201 RA = 21H 30M 54.88S +/- 1950 1 SURF(V) = 15.86 +/- 0.2 0.1S, DEC = -01D 02' 44.2" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3565c [ 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 NGC5272 PC IMAGE P6 F785LP PRE-FLASH=YES 1 100S 1 2 CYCLE 2 / 1-10 PCS MODE F / 1-10 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6093 PC IMAGE P6 F785LP PRE-FLASH=YES 1 200S 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC6171 PC IMAGE P6 F785LP PRE-FLASH=YES 1 300S 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6254 PC IMAGE P6 F785LP PRE-FLASH=YES 1 70S 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC7089 PC IMAGE P6 F785LP PRE-FLASH=YES 1 160S 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC5272 PC IMAGE P6 F555W PRE-FLASH=YES 1 100S 1 2 SEQ 1,6 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC6093 PC IMAGE P6 F555W PRE-FLASH=YES 1 200S 1 2 SEQ 2,7 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC6171 PC IMAGE P6 F555W PRE-FLASH=YES 1 300S 1 2 SEQ 3,8 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC6254 PC IMAGE P6 F555W PRE-FLASH=YES 1 70S 1 2 SEQ 4,9 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC7089 PC IMAGE P6 F555W PRE-FLASH=YES 1 160S 1 2 SEQ 5,10 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3565c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations PC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal for AUG/OS ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 0.25 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR POPULATIONS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 2 / 1-10; PCS MODE F / 1-10 SEQ 1,6 NO GAP; SEQ 2,7 NO GAP ; SEQ 3,8 NO GAP ; SEQ 4,9 NO GAP ; SEQ 5,10 NO GAP ; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F785LP F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC5272 M3 NGC6093 M80 NGC6171 M107 NGC6254 M10 NGC7089 M2 ------------------------------------------------------------------------------------------------------------------------------------