! $Id: 5216,v 37.1 1994/07/27 15:58:08 pepsa Exp $ coverpage: title_1: IO'S VOLCANIC SURFACE AND ATMOSPHERE sci_cat: SOLAR SYSTEM sci_subcat: SATELLITES proposal_for: GTO/WF2 pi_title: DR. pi_fname: JOHN pi_lname: TRAUGER pi_inst: 2370 pi_country: USA pi_phone: 818-354-9594 keywords_1: SATELLITE hours_pri: 4.14 num_pri: 2 wf_pc: Y time_crit: Y pi_position: PROJECT SCIENTIST off_fname: JOHN off_mi: T. off_lname: TRAUGER off_title: DR. off_inst: JET PROPULSION LABORATORY off_addr_1: 4800 OAK GROVE DRIVE off_addr_2: MAIL STOP 179-225 off_city: PASADENA off_state: CA off_zip: 91109 off_country: USA off_phone: 818-354-9594 ! end of coverpage abstract: line_1: We propose a series of UV images of Io's trailing hemisphere to line_2: determine a) the surface distributions of SO2 frost and SO2 gas line_3: absorption, and b) the spatial distribution of the FUV airglow line_4: emissions of S and O. Our main scientific goals are to observe line_5: Io's atmosphere, both through NUV absorption and FUV emission, line_6: and to determine the process by which 1 ton/sec of material is line_7: released into the plasma torus. Io's atmosphere is believed to line_8: be patchy, with spatial variations of up to 1000 times in surface line_9: density, and the airglow emission region extent has just been line_10: determined for the first time with FOS and GHRS spectra. With line_11: the WFPC2 enhanced UV capabilities, we expect to be able to line_12: image the spatial and altitude distributions of the atmosphere, line_13: and image the airglow process to study the interaction between line_14: Io's atmosphere and the corotating plasma torus. ! ! end of abstract general_form_proposers: lname: TRAUGER fname: JOHN title: DR. mi: T. inst: 2370 country: USA esa: N ! lname: CLARKE fname: JOHN title: PROF. mi: T. inst: 2660 country: USA esa: N ! lname: BURROWS fname: CHRIS inst: STSCI country: USA ! lname: CRISP fname: DAVID inst: JPL country: USA ! lname: HOESSEL fname: JOHN inst: UNIV. OF WISCONSIN country: USA ! lname: GALLAGHER fname: JAY inst: UNIV. OF WISCONSIN country: USA ! lname: GRIFFITHS fname: RICHARD inst: JOHNS HOPKINS UNIV country: USA ! lname: HESTER fname: JEFF inst: ARIZONA STATE UNIV. country: USA ! lname: HOLTZMAN fname: JOHN inst: LOWELL OBSERVATORY country: USA ! lname: MOULD fname: JEREMY inst: CALTECH country: USA ! lname: WESTPHAL fname: JAMES inst: CALTECH country: USA ! ! end of general_form_proposers block general_form_text: ! question: 3 section: 1 line_1: Io's disk is 1 arc sec in diameter, and near-UV and visible images line_2: will be obtained with the PC when Io is near western elongation line_3: (and the apparent motion is small): this will provide roughly 20 line_4: pixels across the diameter of the disk. This is lower resolution line_5: than the Voyager visible images, and we will use the Voyager images line_6: together with the visible images (F380W) to determine the line_7: surface morphology for comparison with the near-UV images. The line_8: near-UV images will be taken with filters F218W, F255W, and F336W. line_9: The wavelength region covered by F218W is very sensitive to SO2 line_10: absorption (2 orders of magnitude more than the 2900 A region line_11: previously imaged with FOC), and we may thus resolve the spatial line_12: distribution of this most important atmospheric component on Io. line_13: Three far-UV images to detect the airglow O and S emissions on Io line_14: will be obtained (and co-added) with F160BW. An image with F160BW line_15: and F165LP will separate the solar light reflected by Io. (F380W line_16: images will identify the limb of the satellite.) The NUV and FUV line_17: image sets should be scheduled in ~succesive west elongations of Io line_18: (43 hr apart), to correlate the airglow emissions with the SO2 line_19: atmospheric distribution, since the airglow may be produced by line_20: direct excitation of O and S but also possibly from dissociation/ line_21: excitation of SO2 as suggested by the decrease in the emissions as line_22: Io goes into eclipse observed with HST. These images should also be line_23: scheduled close to the WFPC2 GTO program on the Io plasma torus. ! question: 4 section: 1 line_1: Io can only be imaged with 20 pixels across the disk and in line_2: the UV with the HST. Galileo will have a UV spectrometer, line_3: but no UV imaging capability, so that we expect our UV images line_4: will complement the high angular resolution spectroscopy line_5: to be performed with the Galileo UVS. These images are also a line_6: follow-up program with high signal-to-noise of a GO program of line_7: FOC imaging over cycles 0-1 and 3: J. Clarke of the WFPC2 line_8: science team is a Co-I on the cycle 3 proposal. line_9: We are requesting single images of Io near W elongation at 3 NUV line_10: wavelengths for discrimination in the SO2 spectrum between line_11: surface frost and gas absorption - the spectral region covered line_12: by the filters chosen (not availiable with the FOC) are the most line_13: sensitive to SO2 gas absorption as recently found with the FOS. line_14: The exposure times are estimated based on IUE and HST spectra line_15: of the whole disk of Io. ! question: 5 section: 1 line_1: Io images must be scheduled near orbital elongation from Jupiter, line_2: as indicated in comments in the Obs. Summ. Form. line_3: We also wish to have the Io images taken close in time to the line_4: Io Torus images listed in that program. ! question: 6 section: 1 line_1: Dark time is requested for the FUV exposures series with F160BW. line_2: We are imaging very weak oxygen and sulfur FUV emissions and line_3: therefore need to minimize background signal from the Earth's line_4: H Lyman alpha and oxygen airglow emissions (at 1304 and 1356 A). line_5: The exposures cannot be interrupted due to Io's rotation and line_6: temporal variability in its atmospheric conditions from its line_7: variable volcanic activity. The exposures have been planned line_8: accordingly. ! ! !end of general form text general_form_address: lname: TRAUGER fname: JOHN mi: T. title: DR. category: PI inst: 2370 addr_1: MS 179-225 addr_2: 4800 Oak Grove Drive city: Pasadena state: CA zip: 91109 country: USA phone: 818-354-9594 ! lname: CLARKE fname: JOHN mi: T. title: DR. inst: 2660 phone: 313-747-3540 ! lname: BALLESTER fname: GILDA mi: E. title: DR. inst: 2660 phone: 313-747-3670 ! ! end of general_form_address records ! No fixed target records found solar_system_targets: targnum: 1 name_1: IO-WEST descr_1: SATELLITE IO lev1_1: STD = JUPITER lev2_1: STD = IO wind_1: OLG OF IO BETWEEN 245 295, wind_2: OLG OF JUPITER BETWEEN 300 60, wind_3: SEP OF EUROPA IO FROM EARTH GT 10", wind_4: SEP OF GANYMEDE IO FROM EARTH GT 10", wind_5: SEP OF CALLISTO IO FROM EARTH GT 10" comment_1: THREE SEQUENTIAL NEAR-UV PC IMAGES OF comment_2: IO'S TRAILING HEMISPHERE, ONE PER comment_3: FILTER, TO STUDY DISTRIBUTION OF comment_4: ATMOSPHERIC AND SURFACE SO2. comment_5: SCHEDULE MIDPOINT OF SERIES WHEN IO comment_6: IS NEAR OR AT WESTERN ELONGATION. comment_7: WINDOWS CAN BE EXPANDED SOMEWHAT IF comment_8: NEEDED FOR SCHEDULING. fluxnum_1: 1 fluxval_1: V = 5.2 +/- 0.5 fluxnum_2: 2 fluxval_2: SURF-CONT(2180) = 2 +/- 1 E-14 fluxnum_3: 3 fluxval_3: SURF-CONT(2550) = 4 +/- 1 E-12 fluxnum_4: 4 fluxval_4: SURF-CONT(3360) = 1.3 +/- 1 E-12 fluxnum_5: 5 fluxval_5: SURF-CONT(3800) = 4.5 +/- 1 E-12 ! targnum: 2 name_1: IO-W-FUV descr_1: SATELLITE IO lev1_1: STD = JUPITER lev2_1: STD = IO wind_1: OLG OF IO BETWEEN 245 295, wind_2: OLG OF JUPITER BETWEEN 300 60, wind_3: SEP OF EUROPA IO FROM EARTH GT 10", wind_4: SEP OF GANYMEDE IO FROM EARTH GT 10", wind_5: SEP OF CALLISTO IO FROM EARTH GT 10" comment_1: LONG WFC FAR-UV EXPOSURES OF IO'S comment_2: TRAILING HEMISPHERE (PLUS TWO SHORT comment_3: BACKGROUND EXPOSURES) TO DETECT comment_4: AIRGLOW EMISSIONS. comment_5: SCHEDULE MIDPOINT OF SERIES WHEN IO IS comment_6: NEAR OR AT WESTERN ELONGATION. comment_7: WINDOWS CAN BE EXPANDED SOMEWHAT IF comment_8: NEEDED FOR SCHEDULING. FLUXNUM 2 AND 4 comment_9: INCLUDE TWO EMISSION MULTIPLETS. comment_10: SCHEDULE ON DARK TIME. fluxnum_1: 1 fluxval_1: V = 5.2 +/- 0.5 fluxnum_2: 2 fluxval_2: F-LINE(1304)=2+/-10E-14,W-LINE(1304)=10 fluxnum_3: 3 fluxval_3: F-LINE(1479)=8+/-50E-15,W-LINE(1479)=10 fluxnum_4: 4 fluxval_4: F-LINE(1814)=2+/-10E-14,W-LINE(1814)=10 fluxnum_5: 5 fluxval_5: SIZE = 1.7 +/- 1.5 fluxnum_6: 6 fluxval_6: SURF-CONT-BKG(1900) = 1.5 +/- 1 E-15 fluxnum_7: 7 fluxval_7: SURF-CONT(3800) = 4.5 +/- 1 E-12 ! ! end of solar system targets ! No generic target records found exposure_logsheet: linenum: 1.100 targname: IO-WEST config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F380W num_exp: 1 time_per_exp: 3.3 S s_to_n: 60 fluxnum_1: 5 priority: 1 param_1: ATD-GAIN = 7 param_2: CR-SPLIT=NO req_1: CYCLE 4; req_2: SEQ 1.1 - 1.5 NO GAP; req_3: GUID TOL 0.2"/ 1.1-2.4; comment_1: TAKE VIOLET IMAGE OF IO'S TRAILING comment_2: HEMISPHERE WITH SAME GUIDE STARS AS comment_3: LINENUM 1.2-1.5 TO IDENTIFY LIMB OF comment_4: SATELLITE AND DEFINE VISIBLE SURFACE. ! linenum: 1.200 targname: IO-WEST config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F336W num_exp: 2 time_per_exp: 25.0 S s_to_n: 60 fluxnum_1: 4 priority: 1 param_1: ATD-GAIN = 7 param_2: CR-SPLIT=NO param_3: CR-TOLERANCE=0.1 req_1: CYCLE 4; comment_1: TWO F336W IMAGES OF IO'S TRAILING comment_2: HEMISPHERE (TWO IMAGES FOR CR-SPLIT, comment_3: WILL BE ADDED TO IMPROVE S/N). comment_4: TAKE IMAGES DURING THE SAME HST ORBIT comment_5: TO AVOID BLURRING FROM IO'S ROTATION. ! linenum: 1.300 targname: IO-WEST config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F255W num_exp: 2 time_per_exp: 500.0 S s_to_n: 15 fluxnum_1: 3 priority: 1 param_1: ATD-GAIN = 7 param_2: CR-SPLIT=NO param_3: CR-TOLERANCE=0.1 req_1: CYCLE 4; comment_1: TWO F255W IMAGES OF IO'S TRAILING comment_2: HEMISPHERE (TWO IMAGES FOR CR-SPLIT, comment_3: WILL BE ADDED TO IMPROVE S/N). comment_4: TAKE IMAGES DURING THE SAME HST ORBIT comment_5: TO AVOID BLURRING FROM IO'S ROTATION. ! linenum: 1.400 targname: IO-WEST config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F218W num_exp: 3 time_per_exp: 1020.0 S s_to_n: 16 fluxnum_1: 2 priority: 1 param_1: ATD-GAIN = 7 param_2: CR-SPLIT=NO param_3: CR-TOLERANCE=0.1 req_1: CYCLE 4; comment_1: THREE F218W IMAGES OF IO'S TRAILING comment_2: HEMISPHERE (FOR CR-SPLIT, AND ADDI- comment_3: TION TO IMPROVE S/N). TAKE FIRST comment_4: TWO IMAGES DURING THE SAME HST ORBIT, comment_5: AND THIRD ONE IN NEXT HST ORBIT comment_6: (WITH LINENUM 1.5) TO AVOID BLURRING ! linenum: 1.500 targname: IO-WEST config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F380W num_exp: 1 time_per_exp: 3.3 S s_to_n: 60 fluxnum_1: 5 priority: 1 param_1: ATD-GAIN = 7 param_2: CR-SPLIT=NO req_1: CYCLE 4; comment_1: TAKE VIOLET IMAGE OF IO'S TRAILING comment_2: HEMISPHERE WITH SAME GUIDE STARS AS comment_3: LINENUM 1.1-1.3 TO IDENTIFY LIMB OF comment_4: SATELLITE AND DEFINE VISIBLE SURFACE. ! linenum: 2.100 targname: IO-W-FUV config: WFPC2 opmode: IMAGE aperture: WF4-FIX sp_element: F380W num_exp: 1 time_per_exp: 0.7 S s_to_n: 60 fluxnum_1: 7 priority: 1 param_1: ATD-GAIN = 7 param_2: CR-SPLIT=NO req_1: CYCLE 4; req_2: POS TARG -17.3, +2.5 comment_1: VIOLET IMAGE OF IO'S TRAILING comment_2: HEMISPHERE WITH SAME GUIDE STARS AS comment_3: IN LINENUM 2.1-2.2 TO IDENTIFY comment_4: LIMB OF SATELLITE. ! linenum: 2.200 targname: IO-W-FUV config: WFPC2 opmode: IMAGE aperture: WF4-FIX sp_element: F160BW num_exp: 1 time_per_exp: 1500.0 S s_to_n: 4 fluxnum_1: 6 priority: 1 param_1: ATD-GAIN = 7 param_2: CR-SPLIT = NO param_3: CR-TOLERANCE=0.1 req_1: CYCLE 4; req_2: POS TARG -17.3, +2.5 comment_1: UV IMAGE OF IO'S TRAILING HEMISPHERE comment_2: TO MEASURE FUV BACKGROUND SCATTERED comment_3: LIGHT FROM THE DISK. ! linenum: 2.300 targname: IO-W-FUV config: WFPC2 opmode: IMAGE aperture: WF4-FIX sp_element: F160BW num_exp: 4 time_per_exp: 1000.0 S s_to_n: 4 fluxnum_1: 2 fluxnum_2: 3 fluxnum_3: 4 fluxnum_4: 5 priority: 1 param_1: ATD-GAIN = 7 param_2: CR-SPLIT = NO param_3: CR-TOLERANCE=0.1 req_1: CYCLE 4; req_2: SEQ 2.1 - 2.3 NO GAP; ! req_3: DARK TIME / 2.3; req_4: POS TARG -17.3, +2.5 comment_1: THREE LONG FUV EXPOSURES OF IO'S comment_2: TRAILING HEMISPHERE TO IMAGE AIRGLOW comment_3: EMISSIONS. THREE IMAGES FOR CR-SPLIT, comment_4: TO BE ADDED TO IMPROVE S/N. comment_5: SCHEDULE EXPOSURES CLOSE IN TIME TO comment_6: SEQUENCE 1.1-1.4 TO CORRELATE DATA. ! linenum: 2.400 targname: IO-W-FUV config: WFPC2 opmode: IMAGE aperture: WF4-FIX sp_element: F380W num_exp: 1 time_per_exp: 0.7 S s_to_n: 60 fluxnum_1: 7 priority: 1 param_1: ATD-GAIN = 7 param_2: CR-SPLIT=NO req_1: CYCLE 4; req_2: POS TARG -17.3, +2.5 comment_1: EXECUTE EXPOSURE 2.4 BEFORE OR AFTER comment_2: THE LAST EXPOSURE IN LINENUM 2.3 comment_3: TO CHECK THE POINTING. ! ! end of exposure logsheet ! No scan data records found