! File: 5108C.PROP ! Database: PEPDB ! Date: 23-FEB-1994:20:57:22 coverpage: title_1: STELLAR POPULATIONS IN DWARF SPHEROIDAL GALAXIES (WC05): title_2: CYCLE 4 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) 395-4900 keywords_1: DWARF GALAXIES, LOCAL GROUP, STELLAR POPULATIONS, HR keywords_2: DIAGRAM hours_pri: 5.00 num_pri: 4 wf_pc: Y pi_position: PROFESSOR OF PLANETA ! end of coverpage abstract: line_1: HR diagrams to deep levels using the F555W and F814W filters and line_2: the WFC will be used to study the stellar populations of the line_3: dwarf spheroidal galaxies Carina, Ursa Minor and Fornax. Aspects line_4: to be studied include the star formation histories based on the line_5: location and distribution of stars near the main-sequence turnoff; line_6: the luminosities, colors, and metallicities of stars on the giant line_7: branch; the relation of horizontal-branch morphology to stellar line_8: ages and metallicities; distance moduli via main sequence fitting; line_9: the absolute magnitude of the horizontal branch; the main- line_10: sequence luminosity function; the possible incidence of binaries line_11: on the main sequence; and an estimate of the overall mass-to-light line_12: ratio and space density of baryonic matter in stars. In Fornax, line_13: the proposed field also contains the metal-poor cluster Fornax 4, line_14: whose HR diagram and radial density gradient will also be line_15: 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 F814W 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 F814W . 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 phone: 818-395-4900 ! lname: LIGHT fname: ROBERT mi: M. category: CON inst: IPAC addr_1: M/S 100-22 addr_2: CALTECH city: PASADENA state: CA zip: 91125 country: USA phone: 818-397-9522 ! ! 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 ! 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: 1950.0 comment_1: DWARF SPHEROIDAL GALAXY ! 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: 1950.0 comment_1: GLOBULAR CLUSTER IN FORNAX comment_2: DWARF SPHEROIDAL GALAXY ! 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: 1950.0 comment_1: DWARF SPHEROIDAL GALAXY ! ! 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: WFPC2 opmode: IMAGE aperture: # sp_element: F814W num_exp: # time_per_exp: 200S priority: # param_1: CR-SPLIT=NO, param_2: ATD-GAIN=15 req_1: GROUP 7-10 WITHIN 1D; comment_1: CYCLE 4-5 PROPOSAL 6/3/93 RML ! linenum: 8.000 sequence_1: ^ targname: # config: WFPC2 opmode: IMAGE aperture: # sp_element: F814W num_exp: # time_per_exp: 2200S fluxnum_1: 1 priority: # param_1: CR-SPLIT=0.5, param_2: 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: WFPC2 opmode: IMAGE aperture: # sp_element: F555W num_exp: # time_per_exp: 200S priority: # param_1: CR-SPLIT=NO, param_2: ATD-GAIN=15 ! linenum: 10.000 sequence_1: ^ targname: # config: WFPC2 opmode: IMAGE aperture: # sp_element: F555W num_exp: # time_per_exp: 2200S fluxnum_1: 1 priority: # param_1: CR-SPLIT=0.5, param_2: CR-TOLERANCE=0.0 ! 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 4 / 11-12; ! linenum: 12.000 sequence_1: USE sequence_2: DW2 targname: FORNAX-CLUSTER4 aperture: WFALL num_exp: 1 time_per_exp: X1 priority: 1 ! linenum: 13.000 sequence_1: USE sequence_2: DW2 targname: URSA-MINOR-150812+672300 aperture: WFALL num_exp: 1 time_per_exp: X1 priority: 1 req_1: CYCLE 5 / 13-14; ! linenum: 14.000 sequence_1: USE sequence_2: DW2 targname: DRACO-171922+5757 aperture: WFALL num_exp: 1 time_per_exp: X1 priority: 2 ! ! end of exposure logsheet ! No scan data records found