This phase II proposal has been updated to use ACS/SBC in place of STIS in the original submission. ----- Submission 1 (Sat May 15 18:06:37 GMT 2004) ----- ----- Submission 2 (Fri Oct 29 21:56:50 GMT 2004) ----- Assigned ID: 747 ----- Submission 1 (Fri Jan 23 23:05:39 GMT 2004) ----- Phase I Proposal 747 (hst_satspec13_apt) successfully submitted. Saturn's Auroral Energy Deposition Coordinated with Cassini UVIS An in-depth study of Saturn's magnetosphere and auroral processes has begun in Jan. 2004 with coordinated HST STIS images of Saturn's aurora while the approaching Cassini measures the solar wind. This program is expected to establish the degree of solar wind control of Saturn's aurora. The beginning of the Cassini orbiter tour of the Saturn system in July 2004 will offer new opportunities for collaborative science. The energetics of Saturn's auroral processes can best be studied via low resolution UV spectra of the emissions and the auroral "color ratio". The geometry of the initial Cassini orbits provides the best observing geometry for UVIS measurements of auroral energetics when it is close to Saturn on the night side. At such times, it will be possible to have simultaneous observations of Saturn's southern / dayside aurora with HST STIS and the northern / nightside aurora with Cassini UVIS. Both the distributions of the auroral emissions and the energy of the precipitating particles can be measured simultaneously at conjugate points north and south. This proposal is to conduct one such simultaneous observation, which will demonstrate the potential for future cycles. We request 5 HST orbits to observe a large fraction of one complete Saturn rotation at the same time as Cassini UVIS. The rotational coverage has been shown to be of central importance in recent STIS images of Saturn's auroral activity, which is concentrated in an "active sector" connected with the strongest SKR radio emissions.
This program is tentatively scheduled for 17 Feb. 2005, during a Cassini observing sequence of the night side of Saturn. When the HST orbit is known, we will be able to do the final scheduling. The observations will consist of a 5 orbit sequence starting with an acquisition of a satellite, then a series of STIS UV-MAMA images and spectra of Saturn. All images will be with 25MAMA, and all spectra with G140L. The proposal will need to be scheduled at a specific time to coordinate the observations with Cassini measurements at Saturn. If the 17 Feb. 2005 date does not work out, we can attempt to schedule during another Cassini observing sequence. SOLAR SYSTEM 12 false false false false false SUPPORTED SOLAR SYSTEM PLANET Planet Saturn STD=SATURN STIS/FUV-MAMA Spectroscopic No G140L 1425 STIS/FUV-MAMA Imaging No 25MAMA STIS/FUV-MAMA Imaging No F25SRF2 /private/tmp/OPVisit22715.xml This visit will have to be scheduled in detail after the HST orbital ephemeris is known for 17 Feb. 2005. This date and the listed times are when the Cassini UVIS instrument will be observing Saturn's northern nightside aurora. Please contact PI when the HST orbital ephemeris is known, and we only need an accuracy of tens of minutes in terms of SAA passage, etc. to be able to revise the phase 2 proposal. Orient angle and specification of the location of the aperture on Saturn's disc will be determined once we know the approximate PA_V3 angle for HST observing Saturn. We plan to use POS TARG commands to position the spectrograph aperture properly on Saturn's southern aurora. In orbits where there are two spectra, one will have the slit on the central meridian, and the other will have the slit offset toward the dawn side of the oval. Note that the requested date is approx. one month past Saturn opposition. NOTE: since STIS died, this program has been changed to just imaging with ACS SBC. There is no longer any acquisition, and just imaging. (Tic-Visit :proposal-id 10156 :visit-id "01" :proposal-version -1 :trans-version "20040225" :date "29-Oct-2004 17:52:43.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 647968 :tdrss-contact-duration 0 ) (Tic-Obset :proposal-id 10156 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10156 :visit-id "01" :orbit-number 1 :pcs-time 365 :si-vis-utilization 2804 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10156 :visit-id "01" :orbit-number 2 :pcs-time 300 :si-vis-utilization 2883 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10156 :visit-id "01" :orbit-number 3 :pcs-time 300 :si-vis-utilization 2883 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10156 :visit-id "01" :orbit-number 4 :pcs-time 300 :si-vis-utilization 2883 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10156 :visit-id "01" :orbit-number 5 :pcs-time 300 :si-vis-utilization 2883 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true /private/tmp/OPVisit47066.xml