! File: 1110C.PROP ! Database: PEPDB ! Date: 16-FEB-1994:02:06:03 coverpage: title_1: STELLAR POPULATIONS IN DWARF SPHEROIDAL GALAXIES (WF/PC-06): title_2: CYCLE 3 AND FUTURE-CYCLE CONTINUATION sci_cat: STELLAR POPULATIONS proposal_for: GTO/WFC pi_title: PROF. pi_fname: JAMES pi_mi: A. pi_lname: WESTPHAL pi_inst: CALTECH pi_country: USA pi_phone: (818) 356-4900 keywords_1: DWARF GALAXIES, LOCAL GROUP, STELLAR POPULATIONS, HR keywords_2: DIAGRAM hours_pri: 5.00 num_pri: 4 pi_position: PROFESSOR OF PLANETA ! end of coverpage abstract: line_1: HR diagrams to deep levels using the F555W and F785LP filters and the WFC line_2: will be used to study the stellar populations of the dwarf spheroidal galaxies line_3: Carina, Ursa Minor and Fornax. Aspects to be studied include the star line_4: formation histories based on the location and distribution of stars near the line_5: main-sequence turnoff; the luminosities, colors, and metallicities of stars on line_6: the giant branch; the relation of horizontal-branch morphology to stellar ages line_7: and metallicities; distance moduli via main sequence fitting; the absolute line_8: magnitude of the horizontal branch; the main-sequence luminosity function; the line_9: possible incidence of binaries on the main sequence; and an estimate of the line_10: overall mass-to-light ratio and space density of baryonic matter in stars. In line_11: Fornax, the proposed field also contains the metal-poor cluster Fornax 4, whose line_12: HR diagram and radial density gradient will also be measured. ! ! end of abstract general_form_proposers: lname: WESTPHAL fname: JAMES mi: A. inst: CALTECH country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: A single, one-orbit, dark-time exposure with the WFC is desired in each of line_2: filters F555W and F785LP for each field, plus shorter exposures for cosmic ray line_3: removal and calibration of brighter stars. One field per galaxy. line_5: Distribution of targets with observing period: line_7: 1st Year = Carina, Ursa Minor (Cycle 3) line_8: 2nd Year = Fornax (Cycle 4) ! question: 6 section: 1 line_1: Limiting noise source is readout noise; uninterrupted exposures needed for line_2: maximum S/N. line_4: It is also desired that all exposures longer than 1000 sec be taken after the line_5: telescope has passed beyond the limb of the Earth (see note on "dark time" on line_6: exposure logsheets). It is not requested that the telescope actually be within line_7: the Earth's shadow. Dark time is needed to minimize diffuse scattered light line_8: and maximize S/N on faint stars. The above guideline of 1000 sec may need line_9: modification after real experience in orbit. ! question: 13 section: 1 line_1: HR diagrams are proposed of dwarf spheroidal galaxies using the WFC and filters line_2: F555W and F785LP. Studies include the age and stellar metallicity line_3: distributions, distance moduli, luminosity functions, and stellar mass-to-light line_4: ratios. One field in each of Carina, Ursa Minor, and Fornax is planned. ! !end of general form text general_form_address: lname: WESTPHAL fname: JAMES mi: A. title: PROF. category: PI inst: CALTECH addr_1: M/S 170-25 addr_2: DIVISION OF GEOLOGICAL addr_3: & PLANETARY SCIENCES city: PASADENA state: CA zip: 91125 country: USA ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: CARINA-064024-5055 descr_1: E, 308 pos_1: RA= 06H 40M 35.8S +/- 0.3S, pos_2: DEC= -50D 55' 19" +/- 5" equinox: 1950 comment_1: DWARF SPHEROIDAL GALAXY fluxnum_1: 1 fluxval_1: V= 27.0 +/-0.5 ! targnum: 2 name_1: URSA-MINOR-150812+672300 descr_1: E, 308 pos_1: RA= 15H 07M 55.6S +/- 0.3S, pos_2: DEC= +67D 23' 44" +/- 5" equinox: ^ comment_1: DWARF SPHEROIDAL GALAXY fluxnum_1: 1 fluxval_1: ^ ! targnum: 3 name_1: FORNAX-CLUSTER4 descr_1: E, 308, D, 201 pos_1: RA= 02H 38M 03.2S +/-0.3S, pos_2: DEC= -34D 45' 05" +/-5" equinox: ^ comment_1: GLOBULAR CLUSTER IN FORNAX comment_2: DWARF SPHEROIDAL GALAXY fluxnum_1: 1 fluxval_1: ^ ! targnum: 4 name_1: DRACO-171922+5757 descr_1: E, 308 pos_1: RA= 17H 19M 21.8S +/-0.3S, pos_2: DEC= +57D 57' 36" +/-5" equinox: ^ comment_1: DWARF SPHEROIDAL GALAXY fluxnum_1: 1 fluxval_1: ^ ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 7.000 sequence_1: DEFINE sequence_2: DW2 targname: # config: WFC opmode: IMAGE aperture: # sp_element: F785LP num_exp: # time_per_exp: 200S priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: SEQ 7-10 WITHIN 1D; req_2: SEQ 7-8 NO GAP; req_3: NON-INT / 7-10 comment_1: CYCLE 3-9 PROPOSAL VERSION comment_2: 3/24/92 RML ! linenum: 8.000 sequence_1: ^ targname: # config: WFC opmode: IMAGE aperture: # sp_element: F785LP num_exp: # time_per_exp: 1600S fluxnum_1: 1 priority: # param_1: CR-SPLIT=0.5, param_2: PRE-FLASH=NO, param_3: CR-TOLERANCE=0.0 req_1: SAME POS FOR 8-10 AS 7; req_2: SAME ORIENT FOR 8-10 AS 7; ! linenum: 9.000 sequence_1: ^ targname: # config: WFC opmode: IMAGE aperture: # sp_element: F555W num_exp: # time_per_exp: 200S priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: SEQ 9-10 NO GAP ! linenum: 10.000 sequence_1: ^ targname: # config: WFC opmode: IMAGE aperture: # sp_element: F555W num_exp: # time_per_exp: 2000S fluxnum_1: 1 priority: # param_1: CR-SPLIT=0.5, param_2: PRE-FLASH=NO, param_3: CR-TOLERANCE=0.0 comment_1: EACH FILTER SEQUENCE IS INTENDED TO comment_2: FIT WITHIN ONE ORBIT. comment_3: LONG EXPOSURES ON LINES 8 AND 10 MAY comment_4: ADJUSTED SLIGHTLY TO ENSURE THIS. ! linenum: 11.000 sequence_1: USE sequence_2: DW2 targname: CARINA-064024-5055 aperture: WFALL num_exp: 1 time_per_exp: X1 priority: 1 req_1: CYCLE 3 / 11-13; req_2: POS TARG 10,-10 ! linenum: 12.000 sequence_1: USE sequence_2: DW2 targname: FORNAX-CLUSTER4 aperture: WF2 num_exp: 1 time_per_exp: X1 priority: 2 ! linenum: 13.000 sequence_1: USE sequence_2: DW2 targname: URSA-MINOR-150812+672300 aperture: WFALL num_exp: 1 time_per_exp: X1 priority: 2 req_1: POS TARG 10,-10 ! linenum: 14.000 sequence_1: USE sequence_2: DW2 targname: DRACO-171922+5757 aperture: WFALL num_exp: 1 time_per_exp: X1 priority: 9 req_1: CYCLE 4; req_2: COND IF TAC OK; req_3: POS TARG 10,-10 ! ! end of exposure logsheet ! No scan data records found