This submission uses an updated strategy to attempt to separate Callisto oxygen emission at 1304, 1356A from airglow lines.
Changes (Visit 04 only):
- 3 exposures instead of 4
- avoiding FP-POS=3 to avoid "y-walk" at the most-used spectral locations
- POS TARG of +0.9" in Y to place callisto slightly off center in cross-dispersion direction, moving up (+Y) on detector----- Attempting Submission 1 (Tue Sep 27 15:25:20 GMT 2011) -----Unresolved warning: proposal requires 6 orbits, only 4 allocated. This is due to failure of Visit 2 (2 orbits), which is re-scheduled as Visit 4.COS-GTO: Deep Search for an Oxygen Atmosphere on CallistoWe plan a deep search for 1304? and 1356? O emission from Callisto, to detect or place strong limits on the presence of a hypothesized O2 atmosphere on this moon (Liang et al. 2005). Tenuous oxygen atmospheres on Europa and Ganymede have been detected by HST using these emission lines, but searches for O emission from Callisto have not been successful (Strobel et al. 2002). The Liang et al. models predict O emission at levels comparable to the Strobel et al. upper limit, so the improved sensitivity of COS may be able to detect the emission, and thus Callisto's O2 atmosphere, for the first time.Four orbits with the G130M grating at 1300?, to achieve >= 8000s.SOLAR SYSTEM12false0.00.0falsefalsefalsefalseSUPPORTEDSOLAR SYSTEMWe want to observe Callisto during each visit when it is impacted by Jupiter's tilted & warped current sheet. The Jupiter system III longitudes where Callisto crosses the current sheet are 296 and 116 degrees; we (arbitrarily) choose to observe the crossing centered on 116 degrees. The sheet should cross Callisto during the 1st half of the 2nd orbit; this allows ~25 minutes of flexibility.
Additionally, as the oxygen lines to be observed are also present in terrestrial airglow, we choose to observe near opposition to maximize time in Earth's shadow. We specify this by requiring that the solar elongation of Callisto be greater than 150 degrees (we would prefer >160 degrees, but the period with >160 degree elongation is excluded from the observing window for some reason).SATELLITECALLISTOSTD=JUPITERSTD=CALLISTOF(1356) = 15 RCML OF JUPITER FROM CALLISTO BETWEEN 42 148,
SEP OF CALLISTO SUN FROM EARTH GT 150DEARTHSOLAR SYSTEMWe want to observe Callisto during each visit when it is impacted by Jupiter's tilted & warped current sheet. The Jupiter system III longitudes where Callisto crosses the current sheet are 296 and 116 degrees; we (arbitrarily) choose to observe the crossing centered on 116 degrees. The sheet should cross Callisto during the 1st half of the 2nd orbit; this allows ~25 minutes of flexibility.
Additionally, as the oxygen lines to be observed are also present in terrestrial airglow, we choose to observe near opposition to maximize time in Earth's shadow. We specify this by requiring that the solar elongation of Callisto be greater than 150 degrees (we would prefer >160 degrees, but the period with >160 degree elongation is excluded from the observing window for some reason).SATELLITECALLISTOSTD=JUPITERSTD=CALLISTOF(1356) = 15 RCML OF JUPITER FROM CALLISTO BETWEEN 42 148,
SEP OF CALLISTO SUN FROM EARTH GT 150DEARTHCOS/FUVSpectroscopicNoNoG130MUsing ephemeris for target 11535-02-CALLISTOephemeris data for target 11535-02-CALLISTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 10.220 to 12.245. ephemeris interval: 11.243 to 13.244The scheduling data was generated by CASM 19.3.CASM was run in Phase II mode./private/var/folders/zz/zzzivhrRnAmviuee+++8LE++0Zo/-Tmp-/OPVisit4992703997435010911.xml1283961325000254.6095911128035(Tic-Visit
:proposal-id 11535
:visit-id "02"
:proposal-version -1
:trans-version "20110509"
:date "27-Sep-2011 10:22:48.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 2
:saa-model "31"
:si-bright-earth-limb-angle 20.0
:data-volume 339328
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 11535
:visit-id "02"
:obset-id "02"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 11535
:visit-id "02"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2772
:al-overhead-at-end 0
:internal-dur-at-end 116
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)
(Tic-Orbit
:proposal-id 11535
:visit-id "02"
:orbit-number 2
:pcs-time 222
:si-vis-utilization 2907
:al-overhead-at-end 0
:internal-dur-at-end 428
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)true20Callisto is 6.2 +/- 0.5 mags over 2009 (based on JPL ephem generator), and is effectively 1.1 mag dimmer in this grating bandpass than in the visible (based on albedo = 0.06 here vs. 0.17 in visible).
So I use mV_effective = 7.3 and get 0.44/0.96 seconds for ACQ-Search/ACQ-PeakXD modes to reach S/N = 40 (ETC IDs COS78131 / COS78132). 5 seconds gives plenty of marginCallisto is 6.2 +/- 0.5 mags over 2009 (based on JPL ephem generator), and is effectively 1.1 mag dimmer in this grating bandpass than in the visible (based on albedo = 0.06 here vs. 0.17 in visible).
So I use mV_effective = 7.3 and get 0.44/0.96 seconds for ACQ-Search/ACQ-PeakXD modes to reach S/N = 40 (ETC IDs COS78131 / COS78132)estimates are same as for exposure 1, ACQ/SEARCHCOS76584 for calculation of buffer time. Assumes effective mV = 6.8 and 15 Rayleigh (8.2e-16 ergs/cm^2/s) 1356? line. Gives buffer time = 2/3 * 5939s.Using ephemeris for target 11535-04-CALLISTO-COPYephemeris data for target 11535-04-CALLISTO-COPY does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 10.220 to 12.245. ephemeris interval: 11.243 to 13.244The scheduling data was generated by CASM 19.3.CASM was run in Phase II mode./home/faculty/ncunning/Documents/cos/apt/OP-cache/11535_callisto_njc110927-v04.xml(Tic-Visit
:proposal-id 11535
:visit-id "04"
:proposal-version -1
:trans-version "20110509"
:date "27-Sep-2011 10:14:40.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 2
:saa-model "31"
:si-bright-earth-limb-angle 20.0
:data-volume 243632
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 11535
:visit-id "04"
:obset-id "04"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 11535
:visit-id "04"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2901
:al-overhead-at-end 0
:internal-dur-at-end 116
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)
(Tic-Orbit
:proposal-id 11535
:visit-id "04"
:orbit-number 2
:pcs-time 222
:si-vis-utilization 3012
:al-overhead-at-end 0
:internal-dur-at-end 428
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)true20Callisto is 6.2 +/- 0.5 mags over 2009 (based on JPL ephem generator), and is effectively 1.1 mag dimmer in this grating bandpass than in the visible (based on albedo = 0.06 here vs. 0.17 in visible).
So I use mV_effective = 7.3 and get 0.44/0.96 seconds for ACQ-Search/ACQ-PeakXD modes to reach S/N = 40 (ETC IDs COS78131 / COS78132). 5 seconds gives plenty of marginCallisto is 6.2 +/- 0.5 mags over 2009 (based on JPL ephem generator), and is effectively 1.1 mag dimmer in this grating bandpass than in the visible (based on albedo = 0.06 here vs. 0.17 in visible).
So I use mV_effective = 7.3 and get 0.44/0.96 seconds for ACQ-Search/ACQ-PeakXD modes to reach S/N = 40 (ETC IDs COS78131 / COS78132)estimates are same as for exposure 1, ACQ/SEARCHCOS76584 for calculation of buffer time. Assumes effective mV = 6.8 and 15 Rayleigh (8.2e-16 ergs/cm^2/s) 1356? line. Gives buffer time = 2/3 * 5939s.
POS TARG is designed to place Callisto 0.9" in the cross-dispersion (+Y) direction. This is intended to allow a portion of the the aperture, and therefore a portion of the spectrum, to contain purely airglow, while the upper part of the aperture contains Callisto's spectrum in addition to oxygen airglow. The cross-dispersion variation in oxygen emission line intensity will help indicate whether Callisto has a significant additional oxygen signal.Using ephemeris for target 11535-03-CALLISTOephemeris data for target 11535-03-CALLISTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 10.220 to 12.245. ephemeris interval: 11.243 to 13.244The scheduling data was generated by CASM 19.3.CASM was run in Phase II mode./private/var/folders/zz/zzzivhrRnAmviuee+++8LE++0Zo/-Tmp-/OPVisit8784493125358525671.xml128564647200076.91044921272152(Tic-Visit
:proposal-id 11535
:visit-id "03"
:proposal-version -1
:trans-version "20110509"
:date "27-Sep-2011 10:22:50.0"
:trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0
:FATAL-ERRORS 0 :CONTINUABLE-FATALS 0)
:number-of-orbits 2
:saa-model "31"
:si-bright-earth-limb-angle 20.0
:data-volume 339328
:tdrss-contact-duration 0
:coron NIL
)
(Tic-Obset
:proposal-id 11535
:visit-id "03"
:obset-id "03"
:pcs-mode "FGS"
)
(Tic-Orbit
:proposal-id 11535
:visit-id "03"
:orbit-number 1
:pcs-time 333
:si-vis-utilization 2772
:al-overhead-at-end 0
:internal-dur-at-end 116
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)
(Tic-Orbit
:proposal-id 11535
:visit-id "03"
:orbit-number 2
:pcs-time 222
:si-vis-utilization 2907
:al-overhead-at-end 0
:internal-dur-at-end 428
:dark-offset NIL
:dark-utilization 0
:max-dark-utilization 1920
:low-sky "N"
:pcs-visibility 3234
:pcs-gap 0
)true20Callisto is 6.2 +/- 0.5 mags over 2009 (based on JPL ephem generator), and is effectively 1.1 mag dimmer in this grating bandpass than in the visible (based on albedo = 0.06 here vs. 0.17 in visible).
So I use mV_effective = 7.3 and get 0.44/0.96 seconds for ACQ-Search/ACQ-PeakXD modes to reach S/N = 40 (ETC IDs COS78131 / COS78132)Callisto is 6.2 +/- 0.5 mags over 2009 (based on JPL ephem generator), and is effectively 1.1 mag dimmer in this grating bandpass than in the visible (based on albedo = 0.06 here vs. 0.17 in visible).
So I use mV_effective = 7.3 and get 0.44/0.96 seconds for ACQ-Search/ACQ-PeakXD modes to reach S/N = 40 (ETC IDs COS78131 / COS78132)estimates are same as for exposure 1, ACQ/SEARCH