! File: 4664C.PROP ! Database: PEPDB ! Date: 22-FEB-1994:21:41:17 coverpage: title_1: ASTROPHYSICAL STUDY OF BLUE STRAGGLERS IN 47 TUCANAE: CYCLE 3 HIGH proposal_for: GO pi_title: DR. pi_fname: RONALD pi_lname: GILLILAND pi_inst: STSCI pi_country: USA pi_phone: (410)338-4454 hours_pri: 36.00 num_pri: 1 wf_pc: Y ! end of coverpage abstract: line_1: Through time-series, CCD ensemble photometry of the diverse stellar population line_2: in the core of 47 Tucanae, we will detect stellar oscillations of the delta line_3: Scuti and dwarf Cepheid type in the blue stragglers. We will also determine the line_4: presence and orbital period distribution of contact and cataclysmic binaries in line_5: the cluster core. Similar period distributions to those observed in the field line_6: would support the suggestion that most cataclysmics and contact binaries were line_7: formed in, and ejected from globular clusters. A thorough pulsation study of line_8: the about 25 blue stragglers should allow mass determinations in many cases. As line_9: the blue stragglers of 47 Tuc are likely the result of stellar collisions, these line_10: observations will also yield a thorough survey of the central 66x66 arcsec core line_11: region for tightly bound binaries that may serve as precursors to the formation line_12: of blue stragglers. We will observe with the PC line_13: at a sustained data rate of 3 frames per hour. Since 47 Tuc is in a continuous line_14: viewing zone, such observations will be maintained for a 1.5 day period, line_15: necessary for detection of low amplitude delta Scuti stars, and to obtain the line_16: frequency precisions (8 microHz) needed for detailed interpretation. We expect line_17: a total of about 100 frames over 36 hours, each of which will have precision of line_18: 4 mag on brightest stars (differential only) at 15th mag, to 0.3 mag at 21st. line_19: With some 10000 stars from a most interesting stellar population in this line_20: time-series, many serendipitous results may also be expected. ! ! end of abstract general_form_proposers: lname: GILLILAND fname: RONALD mi: L inst: SPACE TELESCOPE SCIENCE INSTITUTE country: USA ! lname: PETRO fname: LARRY inst: SPACE TELESCOPE SCIENCE INSTITUTE country: USA ! lname: SAHA fname: ABHIJIT inst: SPACE TELESCOPE SCIENCE INSTITUTE country: USA ! lname: SHARA fname: MIKE inst: SPACE TELESCOPE SCIENCE INSTITUTE country: USA ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: Not entered for Phase II. ! question: 3 section: 1 line_1: A primary time-series consisting of some 100 PC exposures most of 17 minutes line_2: with F336W. Observations must be obtained when object is well placed in the line_3: continuous viewing zone, allowing for dense coverage in a 1.5 day window. Each line_4: frame will be taken under conditions as identical as possible to the others. line_5: These frames will be used mainly to provide fully differential photometry of line_6: some 10000 stars in the 66X66 arcsec field of view. The about 25 blue line_7: stragglers are primary targets for detection of stellar pulsations. The line_8: frames will also be co-added and analyzed to provide a U magnitude for each line_9: star. Use of F336W suppresses the much brighter red giants sufficiently to line_10: allow good separation of the blue stragglers. Use of a filter in the UV line_11: would not allow sufficiently high count rates for limiting precision work on line_12: 16th mag stars. Use of a filter farther to the red would not sufficiently line_13: isolate the blue stragglers from the more common stellar types. line_15: Astrophysical analysis of any detected pulsating stars is likely to require line_16: estimates of luminosity and temperature. A few short B and V band exposures line_17: of the primary field are included for this purpose. ! question: 4 section: 1 line_1: The spatial density of stars in the core of 47 Tuc (or any intrinsically high line_2: mass density globular) is very high. Most of the primary program stars have line_3: comparably bright neighbors within about 1-2 arcsec in the U band (much worse line_4: in B, or redder). High precision time-series photometry in such a crowded line_5: field is not feasible with variable seeing as would hold for ground based line_6: observations. The primary targets are, however, well separated at the 0.2-0.4 line_7: arcsec level (Paresce, Shara et al. 1991). Thus the PSF cores containing line_8: about 20% of total energy may be easily measured with PC data. line_9: This project makes full use of current WF/PC and HST (as a system) unique line_10: capabilities. line_11: Our primary goal is detection of stellar pulsations likely to have line_12: characteristic frequencies of 60 to 300 microHz (4.6 to 0.9 hours). line_13: A frequency resolution of 8 microHz as provided by a 36 hour window should line_14: support mode identification for most delta Scuti stars that show both the line_15: fundamental and first overtone modes. Reaching the desired overall precision line_16: level of a few mmag also requires about 100 frames, consistent with 1.5 days. line_18: It would be permissible for the outer limits of the time-series to fall line_19: outside the CVZ, thus resulting in small gaps. Some gaps will certainly line_20: result from SAA passages. ! question: 5 section: 1 line_1: TIME-CRITICAL -- our target has only one lengthy CVZ passage in 1993 line_2: beginning about 1992.247:22:01. The following information from PIT: line_3: GS ACQ (247:19:29) Initial 2 pair fine lock acquisition - BASE2 line_4: LINE01 (247:20:24) Reacq followed by 4 900 sec exposures line_5: LINE02 (247:22:01) Enter SAA free CVZ period - start taking 1000 sec PC images line_6: and keep taking them until next SAA encounter. We should get approx. 32 images. line_7: LINE03 (248:08:46) Start SAA passage portion - 3 images per visibility period line_8: for 6 orbits. line_9: LINE04 (248:18:49) Take 4 900 sec images. line_10: LINE05 (248:20:28) Take 4 1000 sec images. line_12: Start new obset: line_13: LINE06 (248:22:04) Back into SAA free CVZ period. Starting taking 1000 sec line_14: images again and keep taking until CVZ exit. Bright earth limb should line_15: be set to at least 18 deg for this obset. This time will overlap the SMS line_16: boundary and require that the 242 SMS be extended by at least 12 hours. line_17: I have received SMS honcho and GSFC's (J. Leibee) approval to do this. line_18: Start new obset: line_19: LINE08 (249:09:20) Back to observing with short visibility periods for last line_20: 6 exposures. These may take up to 6 orbits to obtain due to very bad line_21: SAA versus visibility period impact. line_22: LINE09-16: These exposures can be obtained anywhere in the 93.249 SMS. ! question: 6 section: 1 line_1: No special calibrations required. A decontamination as necessary to line_2: maintain relative throughput at 70-80% at F336W would be good. line_3: Dense star cluster will provide a mean exposure level of 125 e/1000s exposure line_4: removing the need for a pre-flash. line_5: Similarly there is no need for CR-SPLIT. ! question: 7 section: 1 line_1: Not given for Phase II. ! question: 8 section: 1 line_1: This proposal will rely on a single guide star acquisition to support 36 hours line_2: of observation. Being centered on 47 Tuc this is a generally crowded field. line_3: We request that special attention be paid to the guide star selection to line_4: include: 1) sending up 2 guide star pairs instead of the default one, 2) line_5: have SPSS generate the guide star candidates ahead of time and have Conrad line_6: Sturch visually examine the plate material for these -- this should be noted line_7: on the initial SPB Order Form. line_8: The CVZ passage straddles an SMS boundary, we request either a special SMS line_9: without this break, or an addition of the lost time to the ends of the time line_10: series. line_11: Priority is to schedule as many exposures, all of same length, as possible line_12: in the roughly 36 hour window. It is not desired to maintain even spacings line_13: across gaps. Loss of part of a CCD frame at reversals of the tape recorder line_14: can be lived with. line_15: Attempts should be made to minimize data taking gaps as much as possible. line_16: Note on Guide Stars: 47 Tuc was previously observed with the PC at nearly line_17: the same roll for the Bahcall program, would a check of what guide stars line_18: worked in that case help here? ! question: 9 section: 1 line_1: Not entered for Phase II. ! question: 10 section: 1 line_1: Not entered for Phase II. ! !end of general form text general_form_address: lname: Gilliland fname: Ronald mi: L category: PI inst: STSCI addr_1: 3700 San Martin Dr city: Baltimore state: MD zip: 21218 country: USA phone: 410 338-4454 ! lname: Petro fname: Larry category: CON inst: STSCI addr_1: 3700 San Martin Dr city: Baltimore state: MD zip: 21218 country: USA phone: 410 338-4501 ! lname: Saha fname: Abhijit category: CON inst: STSCI addr_1: 3700 San Martin Dr city: Baltimore state: MD zip: 21218 country: USA phone: 410 338-4806 ! lname: Shara fname: Mike category: CON inst: STSCI addr_1: 3700 San Martin Dr city: Baltimore state: MD zip: 21218 country: USA phone: 410 516-4543 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC104 name_2: 47TUC descr_1: C,201,A,172,175,149 pos_1: RA=00H 24M 05.90S +/- 0.1S, pos_2: DEC=-72D 04' 51.2" +/- 1.0" equinox: 2000 pm_or_par: NO fluxnum_1: 1 fluxval_1: V = 16.0 +/- 0.1 fluxnum_2: 2 fluxval_2: B-V = 0.3 +/- 0.1 fluxnum_3: 3 fluxval_3: E(B-V) = 0.04 +/- 0.03 ! targnum: 2 name_1: NGC104-OFF1 descr_1: C,201,A,172,175,149 pos_1: RA=00H 27M +/- 1S, pos_2: DEC=-72D 35M +/- 1" equinox: 2000 pm_or_par: NO ! targnum: 3 name_1: NGC104-OFF2 descr_1: C,201,A,172,175,149 pos_1: RA=00H 21M +/- 1S, pos_2: DEC=-71D 35M +/- 1" equinox: 2000 pm_or_par: NO ! targnum: 4 name_1: NGC104-OFF3 descr_1: C,201,A,172,175,149 pos_1: RA=00H 30M +/- 1S, pos_2: DEC=-73D 05M +/- 1" equinox: 2000 pm_or_par: NO ! targnum: 5 name_1: NGC104-OFF4 descr_1: C,201,A,172,175,149 pos_1: RA=00H 18M +/- 1S, pos_2: DEC=-71D 05M +/- 1" equinox: 2000 pm_or_par: NO ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F336W num_exp: 4 time_per_exp: 900S s_to_n: 200 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: AT 6-SEP-93 +/- 4D; req_2: SAME POS FOR 2.0-16.0 AS 1.0; req_3: PCS MODE F / 1.0-16; req_4: CYCLE 3 / 1.0-16; req_5: SEQ 1-8 NO GAP; comment_1: SCHEDULE PER COMMENTS IN GF 5. ! linenum: 2.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F336W num_exp: 32 time_per_exp: 1000S s_to_n: 200 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO comment_1: ASSUME CVZ VIS. ! linenum: 3.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F336W num_exp: 18 time_per_exp: 1000S s_to_n: 200 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO comment_1: ASSUME 72 MIN VIS. ! linenum: 4.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F336W num_exp: 4 time_per_exp: 900S s_to_n: 200 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO comment_1: ASSUME 81 MIN VIS. ! linenum: 5.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F336W num_exp: 4 time_per_exp: 1000S s_to_n: 200 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO comment_1: ASSUME 86 MIN VIS. ! linenum: 6.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F336W num_exp: 29 time_per_exp: 1000S s_to_n: 200 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO comment_2: ASSUME CVZ VIS. NEW OBSET HERE. SET comment_3: EARTH LIMB TO 18. ! linenum: 8.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F336W num_exp: 6 time_per_exp: 1000S s_to_n: 200 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO comment_1: ASSUME 47 MIN VIS. RESET EARTH LIMB. ! linenum: 9.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F439W num_exp: 1 time_per_exp: 20S s_to_n: 50 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: AFTER 8; req_2: SEQ 9-16 NO GAP; ! linenum: 10.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F555W num_exp: 1 time_per_exp: 8S s_to_n: 50 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO comment_1: (LINES 3.0-10.0) THESE ARE INDEPENDENT comment_2: OF THE PRIMARY TIME_SERIES IN 1.0-2.0 ! linenum: 11.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F439W num_exp: 1 time_per_exp: 35S s_to_n: 70 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO ! linenum: 12.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F555W num_exp: 1 time_per_exp: 16S s_to_n: 70 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO ! linenum: 13.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F439W num_exp: 1 time_per_exp: 70S s_to_n: 100 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO ! linenum: 14.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F555W num_exp: 1 time_per_exp: 30S s_to_n: 100 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO ! linenum: 15.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F439W num_exp: 1 time_per_exp: 160S s_to_n: 200 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO ! linenum: 16.000 targname: NGC104 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F555W num_exp: 1 time_per_exp: 60S s_to_n: 200 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO, param_3: PURGE=YES ! linenum: 100.000 targname: NGC104-OFF1 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F555W num_exp: 1 time_per_exp: 40S fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO, req_1: SELECT 1 OF 100 OR 101 OR req_2: 102 OR 103; COND IF GS AVAIL; req_3: CYCLE 3/100-103; ! linenum: 101.000 targname: NGC104-OFF2 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F555W num_exp: 1 time_per_exp: 40S fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO, ! linenum: 102.000 targname: NGC104-OFF3 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F555W num_exp: 1 time_per_exp: 40S fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO, ! linenum: 103.000 targname: NGC104-OFF4 config: PC opmode: IMAGE aperture: PCALL-FIX sp_element: F555W num_exp: 1 time_per_exp: 40S fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO, ! ! end of exposure logsheet ! No scan data records found