! $Id: 25,v 4.1 1994/07/26 20:54:06 pepsa Exp $ coverpage: title_1: THE EXCITATION OF THE ATMOSPHERES OF PLANETARY SATELLITES sci_cat: SOLAR SYSTEM proposal_for: GO pi_title: DR. pi_fname: JOE pi_lname: ASTRONOMER pi_inst: STSCI pi_country: USA pi_phone: (301) 338-4700 keywords_1: PLANETARY SATELLITE, PLASMA TORUS, AURORA hours_pri: 2.00 num_pri: 2 fos: X time_crit: X ! end of coverpage abstract: line_1: We will observe Io at near and far UV wavelengths in a set of line_2: observations designed to study the excitation of the line_3: satellite atmospheres. The distinguishing element of this line_4: program is the design of the observations to separate the line_5: following processes: resonant scattering of solar emission, line_6: charged particle excitation by magnetospheric plasma, and (in line_7: the case of Io) the decay of the atmosphere in the absence of line_8: solar-driven sublimation from the surface. Io will be line_9: observed with the FOS/HST combination in the far-UV over a line_10: period of time centered on the passage of Io into eclipse to line_11: separate the solar emissions (while sunlit) from particle line_12: excited emissions (while in shadow) and the near UV SO2 line_13: aurora will be observed while Io is in shadow. The far UV line_14: lines of atomic sulfur and oxygen emanate from an extended line_15: atmosphere, and are produced by a combination of resonant line_16: scattering of solar emission and plasma impact relatively line_17: high in the atmosphere. The near-UV bands of SO reflect line_18: particle impact on SO2, the parent molecule believed to be line_19: driven by sublimation vapor pressure from the surface, and line_20: may be excited relatively closer to Io's surface (due to the ! ! end of abstract general_form_proposers: lname: ASTRONOMER fname: JOE title: DR. inst: SPACE TELESCOPE SCIENCE INSTITUTE country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: The observations will consist of: i) a series of FOS/blue line_2: 4.3 arc sec aperture 15 min. RAPID spectra of Io beginning line_3: 10-15 minutes before eclipse disappearance of Io for a period line_4: of 40 min. (or as long as possible in one dark orbit), and line_5: ii) a series of FOS G270H 4.3 arc sec aperture 15 min. RAPID line_6: spectra beginning near the time of eclipse disappearance for line_7: one dark orbit. The total is 2 dark orbits with the priority line_8: listed above. Acquisition of Io requires short spectra at line_9: different y-deflections to center in y (IO_TA). Using the 4.3 line_10: arc sec aperture to optimize the sensitivity to diffuse line_11: emission, we request coarse track to avoid any loss of lock. line_12: In both cases, Io is to be observed when it is in the active line_13: sector of Jupiter's magnetic field and also in the Io plasma line_14: torus, i.e. when the sub-Io CML of Jupiter is 240-310 line_15: degrees. ! question: 4 section: 1 line_1: Justification for use of HST goes here. ! question: 5 section: 1 line_1: As discussed above, the efficiency of the HST/FOS to a 1 arc line_2: sec object with G130H is roughly 0.5 cts/sec-kR for diffuse line_3: emission; HST/FOS with G270H and 1 arc sec aperture will line_4: yield roughly 2 cts/sec-kR. The S/N estimates given above line_5: are based on 30-40 min. integrations in a single dark orbit line_6: per observation. The time for acquisition of two guide stars line_7: in coarse track (no fine lock) is estimated to be 5 min. FOS line_8: acquisitions cannot be used while tracking Io with track 51, line_9: so a real-time uplink is needed to center Io in the line_10: Y-direction (1.3 arc sec diode length). We will accept the line_11: blind blind ponting in X. We define a target IO-TA for 5 line_12: spectra of Io in sunlight at different y-deflections: the line_13: real-time uplink will be used to select the optimum line_14: y-deflection for the science data. ! question: 6 section: 1 line_1: The observations of Io must begin 10-15 minutes before Io line_2: eclipse disappearance. To be able to follow Io in the line_3: shadow of Jupiter, the sun-Earth-Jupiter angle must be 90 +/- line_4: 25 degrees. ! question: 7 section: 1 line_1: A description of your data reduction plans go here. ! question: 8 section: 1 line_1: Any additional comments go here. ! question: 9 section: 1 line_1: A description of any previous HST data goes here. ! question: 10 section: 1 line_1: Resources provided by your home institution goes here. ! !end of general form text general_form_address: lname: ASTRONOMER fname: JOE title: DR. category: PI inst: STSCI addr_1: 3700 SAN MARTIN DRIVE city: BALTIMORE state: MD zip: 21218 country: USA phone: (301) 338-4700 ! ! end of general_form_address records ! No fixed target records found solar_system_targets: targnum: 1 name_1: IO descr_1: SATELLITE IO lev1_1: STD = JUPITER lev2_1: STD = IO wind_1: OLG OF JUPITER BETWEEN 54 104, wind_2: ECL U OF IO BY JUPITER, wind_3: CML OF JUPITER FROM IO BETWEEN 240 310, wind_4: SEP OF EUROPA IO FROM EARTH GT 10", wind_5: SEP OF GANYMEDE IO FROM EARTH GT 10", wind_6: SEP OF CALLISTO IO FROM EARTH GT 10" comment_1: OBSERVE IO GOING INTO ECLIPSE comment_2: BEHIND JUPITER; BEGIN G130H SERIES comment_3: 10-20 MIN AND G270H SERIES 0-9 comment_4: MINUTES BEFORE IO ECLIPSE comment_5: DISAPPEARANCE AND SCHEDULE comment_6: WHEN EARTH-SUN-JUPITER ANGLE IS comment_7: 54-104 DEGREES AND CML OF SUB-IO comment_8: POINT ON JUPITER IS 240-310 DEG. comment_9: PLEASE NOTE THAT THE WINDOWS CAN comment_10: BE EXPANDED IF NEEDED TO SCHEDULE. fluxnum_1: 1 fluxval_1: SURF(V) = 5.8 +/- 0.5 fluxnum_2: 2 fluxval_2: SIZE = 1.0 +/- .2 fluxnum_3: 3 fluxval_3: SURF-CONT(2700) = 2 +/- 1 E-13 ! targnum: 2 name_1: IO-TA descr_1: SATELLITE IO lev1_1: STD = JUPITER lev2_1: STD = IO comment_1: IO-TA IS IO IN SUNLIGHT FOR TARGET comment_2: ACQUISITION WITH FOS. THIS WILL BE A comment_3: SET OF 5 SPECTRA AT DIFFERENT comment_4: Y-DEFLECTIONS TO DETERMINE WHERE IO comment_5: IS CENTERED ON THE 1.3 ARC SEC LONG comment_6: FOS DIODES. fluxnum_1: 1 fluxval_1: SURF(V) = 5.8 +/- 0.5 fluxnum_2: 2 fluxval_2: SIZE = 1.0 +/- .2 fluxnum_3: 3 fluxval_3: SURF-CONT(2700) = 2 +/- 1 E-13 fluxnum_4: 4 fluxval_4: SURF-CONT(1600) = 2 +/- 1 E-14 ! ! end of solar system targets ! No generic target records found exposure_logsheet: linenum: 1.000 targname: IO-TA config: FOS/BL opmode: IMAGE aperture: 4.3 sp_element: G270H num_exp: 1 time_per_exp: 300 S fluxnum_1: 2 priority: 1 param_1: Y-SIZE = 5, param_2: Y-SPACE = 128, param_3: COMB = YES, param_4: SUB-STEP = 4 req_1: RT ANALYSIS FOR 2-3.1; req_2: CYCLE 1 /1-6.1; comment_1: FOS SPECTRA OF IO FOR TARGET ACQ. comment_2: BEFORE EA. OF 2 SPECTROSCOPY SESSIONS: comment_3: W/ G130H AND G270H. REQUIRES RT UPLINK comment_4: WILL UPLINK CORRECT POINTING DURING comment_5: EARTH OCC BASED ON 5 SPECTRA IN OSS comment_6: IO WILL BE RE-ACQ'D.TAKE 2-3 POST OCC. ! linenum: 2.000 targname: IO-TA config: FOS/BL opmode: IMAGE aperture: 4.3 sp_element: G270H num_exp: 1 time_per_exp: 4.0S fluxnum_1: 2 priority: 2 param_1: STEP-TIME = 1.0, param_2: SUB-STEP = 1, param_3: Y-SIZE = 4, param_4: Y-SPACE = 64, param_5: COMB = NO req_1: SEQ 2-3.1 NO GAP; comment_1: QUICK MAP OF 4.3 APERTURE,AFTER UPLINK comment_2: CORRECTING POINTING, TO DETERMINE TRUE comment_3: LOCATION OF IO IN APERTURE. ! linenum: 3.000 targname: IO config: FOS/BL opmode: RAPID aperture: 4.3 sp_element: G130H wavelength: 1368. num_exp: 1 time_per_exp: 1590S fluxnum_1: 1 priority: 1 param_1: STEP-PATT = DEF, param_2: READ-TIME = 40 comment_1: BEGIN EXPOSURES AFTER ACQ MAP comment_2: AND 5-10 MINUTES BEFORE IO comment_3: ECLIPSE DISAPPEARANCE. ! linenum: 3.100 targname: IO config: FOS/BL opmode: RAPID aperture: 4.3 sp_element: G130H wavelength: 1368. num_exp: 1 time_per_exp: 170S fluxnum_1: 1 priority: 1 param_1: STEP-PATT = DEF, param_2: READ-TIME = 40 ! linenum: 4.000 targname: IO-TA config: FOS/BL opmode: IMAGE aperture: 4.3 sp_element: G270H num_exp: 1 time_per_exp: 300S fluxnum_1: 2 priority: 1 param_1: Y-SIZE = 5, param_2: Y-SPACE = 128, param_3: COMB = YES, param_4: SUB-STEP = 4 req_2: RT ANALYSIS FOR 5-6.1 comment_1: 5-STEP IMAGE FOR RT POINTING comment_2: CORRECTION BEFORE 5,6. MUST OCCUR comment_3: WITH IO IN SUNLIGHT. ! linenum: 5.000 targname: IO-TA config: FOS/BL opmode: IMAGE aperture: 4.3 sp_element: G270H num_exp: 1 time_per_exp: 4.0S fluxnum_1: 2 priority: 3 param_1: STEP-TIME = 1.0, param_2: SUB-STEP = 1, param_3: Y-SIZE = 4, param_4: Y-SPACE = 64, param_5: COMB = NO req_1: SEQ 5-6.1 NO GAP; comment_1: QUICK MAP OF 4.3 APER FOR comment_2: GROUND TRUTH POINTING INFO. comment_3: MUST OCCUR BEFORE LINE 6. ! linenum: 6.000 targname: IO config: FOS/BL opmode: RAPID aperture: 4.3 sp_element: G270H num_exp: 1 time_per_exp: 1590S fluxnum_1: 1 priority: 1 param_1: STEP-PATT = DEF, param_2: READ-TIME = 40. comment_1: 40 S. SPECTRA OF IO: BEGIN 0-5 comment_2: MIN. BEFORE ECLIPSE OF IO BY comment_3: JUPITER. ! linenum: 6.100 targname: IO config: FOS/BL opmode: RAPID aperture: 4.3 sp_element: G270H num_exp: 1 time_per_exp: 170S fluxnum_1: 1 priority: 1 param_1: STEP-PATT = DEF, param_2: READ-TIME = 40. ! ! end of exposure logsheet ! No scan data records found