! $Id: 5321,v 7.1 1994/07/27 16:34:08 pepsa Exp $ coverpage: title_1: RECOVERY OF INNER SATELLITES OF URANUS title_2: CYCLE4MEDIUM sci_cat: SOLAR SYSTEM sci_subcat: SATELLITES proposal_for: GO pi_fname: KENNETH pi_lname: SEIDELMANN pi_inst: 3630 pi_country: USA pi_phone: 202-653-1545 hours_pri: 0.09 num_pri: 12 wf_pc: Y funds_amount: 50000 funds_length: 12 off_fname: IRENE off_lname: MANFORD off_title: MANAGER OF CONTRACTS off_inst: COMPUTER SCIENCES CORP. off_addr_1: 4061 POWDER MILL ROAD off_city: CALVERTON off_state: MD off_zip: 20705 off_country: USA off_phone: (301) 572-3636 ! end of coverpage abstract: line_1: Ten inner satellites of Uranus were discovered by Voyager 2 at the line_2: beginning of 1986. Since the observations were taken over only a one- line_3: month period, their orbital positions are currently uncertain by 5 to line_4: 110 degrees. No spectral data were obtained by Voyager, and the line_5: objects have not been observed since. line_7: We propose to recover these satellites with the Planetary Camera of line_8: the WFPC2, in order to determine positions which will provide accurate line_9: mean motions and improved orbital elements. The accurate mean motions line_10: will permit investigations of dynamical resonances which are known to line_11: exist among the satellites and with the rings. Also we will take line_12: images in multiple filters to obtain some information about the line_13: compositions of the satellites. The improved ephemerides resulting line_14: from this work will allow more detailed study of the objects with the line_15: Faint Object Spectrograph in subsequent HST cycles. ! ! end of abstract general_form_proposers: lname: SEIDELMANN fname: KENNETH inst: 3630 country: USA ! lname: PASCU fname: DAN inst: 3630 country: USA ! lname: CURRIE fname: DOUGLAS inst: 2620 country: USA ! lname: KOWAL fname: CHARLES inst: 1780 country: USA ! lname: WELLS fname: EDDIE inst: 1780 country: USA ! lname: ZELLNER fname: BEN inst: 1780 country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: We propose to take paired images of the inner satellites of Uranus in line_2: B, V, R, and I filters in the Planetary Camera during three visits, line_3: each visit taking one HST orbit. The orbital periods of the line_4: satellites are such that the visits should be separated by line_5: approximately six hours or four HST orbits. Eleven short exposures line_6: will be taken on each visit, for three visits. No interactive or line_7: onboard target acquisition will be needed. line_8: The PC frames will also contain well-exposed images of the satellites line_9: Miranda and Ariel, which have accurately known ephemerides and will line_10: independently calibrate the roll angle of each frame and provide a line_11: check on the plate scale. They will also provide the photometric and line_12: colorimetric calibration. Uranus itself will be allowed to saturate line_13: (but not bloom) on the CCDs, and all astrometric reductions will be line_14: done in a satellite-to-satellite mode without reference to the line_15: planet. line_16: Since Uranus will generally be saturated we do not expect to obtain line_17: useful images of the planet, or of its rings. However if any of the line_18: images should show planetary or ring features we will call upon line_19: experts in the appropriate fields for analysis and interpretation. line_20: Wide-band filters are chosen to maximize photon count while keeping line_21: the exposures short enough to avoid motion blur. We will track on line_22: Uranus, and due to their orbital motions the satellites would blur line_23: more than one PC pixel in about 60 seconds, which is the limiting ! question: 3 section: 2 line_1: factor for the B filter. In V and R the image of Uranus would bloom line_2: in exposures longer than about 18 and 26 seconds, respectively. line_3: Finally, exposures in the I filter are limited to about 50 seconds to line_4: avoid blooming of Ariel. line_5: In the baseline exposures Ariel will saturate in V, R, and I, so we line_6: also propose to add a shorter exposure (5 to 10 seconds) in each. In line_7: one HST orbital visibility period it should be possible to do each line_8: baseline exposure twice to facilitate recognition and removal of line_9: cosmic rays, plus each shorter exposure once, for a total of 11 line_10: images per visit. ! question: 4 section: 1 line_1: The inner satellites of Uranus have not been observed from the line_2: ground, and due to the uncertainties of their orbital positions they line_3: cannot presently be observed by small-aperture techniques from space. line_4: Until improved orbits are obtained they can only be observed with line_5: the Hubble Space Telescope in an imaging mode. ! question: 5 section: 1 line_1: Uranus will be at opposition on July 17, 1994, and the optimum line_2: geometry would be obtained within a few weeks of opposition. However line_3: Uranus is so distant that little resolution or signal would be lost line_4: even if pointing constraints of HST should continue to require that line_5: the observations be made several months away from opposition. ! question: 6 section: 1 line_1: Unless there are unexpected problems with the flat-field properties, line_2: noise, or stability of the WFPC2 Planetary Camera, no special line_3: calibrations should be required. ! ! question: 8 section: 1 line_1: None. ! question: 9 section: 1 line_1: Seidelmann and Currie are members of the WF/PC IDT Team. The GTO line_2: programs are not closely related to this proposal. line_3: Zellner is PI of the following programs, none of which are closely line_4: related to this proposal: line_5: - A solar-system Target of Opportunity proposal was submitted for HST line_6: Cycle 1 with Co-Investigators including Seidelmann, Pascu, and Kowal. line_7: It was approved as program 2432 and was activated in April 1992 for line_8: PC images of newly discovered object 1992AD = 5145 Pholus. line_9: - A Target of Opportunity proposal essentially identical to 2432 was line_10: submitted for Cycle 3 and approved as program 4527. It will be line_11: activated if a sufficiently interesting target should appear. line_12: - Program 3744, "Spectrophotometry of Phobos and Deimos" was line_13: initially approved but not executed for Cycle 1, then re-submitted line_14: and approved for Cycle 2. Observations were taken in late 1992 and line_15: early 1993. line_16: - Program 4521, "Asteroid Shape and Duplicity", has been approved for line_17: Cycle 3. We expect that the first observations will be taken in July line_18: 1993. line_19: Zellner and Wells were associated with HST DD program 4748 for images line_20: of the earth-approaching object 4179 Toutatis in December 1992. line_21: Zellner is also co-investigator on a DD program, approved but not yet line_22: numbered at this writing, for images and spectrophotometry of comet line_23: 1993e in mid-1993. ! question: 10 section: 1 line_1: Kowal, Wells, and Zellner will be chiefly responsible for Phase II line_2: proposal submission, for actual implementation of the program, and line_3: for reduction and deconvolution of the raw data. Mainframe computers line_4: and peripherals and STSDAS software for reduction of the raw images line_5: are available at STScI. A VaxStation 4000 Model 60 is budgeted in line_6: Cycle 3 program 4521 for analysis of PC images of asteroids and will line_7: also be used for this program. A cpu upgrade to Model 90 is budgeted line_8: here. CSC also provides a pool of research assistants and data line_9: technicians as well as administrative and secretarial support for line_10: research programs. line_11: The U. S. Naval Observatory will provide the necessary computer line_12: facilities, readily available software, and personnel time of the PI line_13: and Co-I for scientific analysis, interpretation, and communication line_14: of the results. Only support for temporary help for data analysis is line_15: being requested here. line_16: The University of Maryland will provide, as a contribution to this line_17: project, one man month of effort by Professor Currie. It will also line_18: contribute the use of two University of Maryland computing systems, line_19: DEC 3100 computers, to be used as needed to perform the image analysis line_20: required for this project. ! !end of general form text general_form_address: lname: Seidelmann fname: Kenneth category: PI inst: 3630 addr_1: U S Naval Observatory addr_2: Orbital Mechanics Dept addr_3: 3450 Massachusetts Ave., N.W. city: Washington, DC zip: 203925420 country: USA phone: 202-653-1545 telex: omd@ariel.usno.navy.mil ! lname: KOWAL fname: CHARLES mi: T. category: CON inst: 1780 addr_1: SPACE TELESCOPE SCIENCE INSTITUTE addr_2: 3700 SAN MARTIN DRIVE city: BALTIMORE state: MD zip: 21218 country: USA phone: (410) 338-4535 telex: kowal@stsci ! ! end of general_form_address records ! No fixed target records found solar_system_targets: targnum: 1 name_1: URANUS descr_1: PLANET URANUS lev1_1: STD = URANUS fluxnum_1: 1 fluxval_1: V=5.5 +/- 1.0 ! ! end of solar system targets ! No generic target records found exposure_logsheet: linenum: 1.000 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F439W num_exp: 1 time_per_exp: 60S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; req_2: GROUP 1.000-1.061 NO GAP ! linenum: 1.001 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F439W num_exp: 1 time_per_exp: 120S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! linenum: 1.010 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F569W num_exp: 1 time_per_exp: 10S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! linenum: 1.020 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F569W num_exp: 1 time_per_exp: 18S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! linenum: 1.021 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F569W num_exp: 1 time_per_exp: 35S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! ! linenum: 1.030 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F675W num_exp: 1 time_per_exp: 8S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! linenum: 1.040 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F675W num_exp: 1 time_per_exp: 26S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! linenum: 1.041 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F675W num_exp: 1 time_per_exp: 50S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! linenum: 1.050 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F791W num_exp: 1 time_per_exp: 12S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! linenum: 1.060 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F791W num_exp: 1 time_per_exp: 50S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! linenum: 1.061 targname: URANUS config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F791W num_exp: 1 time_per_exp: 100S s_to_n: 1 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; req_2: REPEAT 1.000-1.061 EVERY 6H +/- 3H req_3: FOR 2 MORE TIMES ! ! end of exposure logsheet ! No scan data records found