The program has been modified to: (a) fill all of orbits 1 - 4 (I went back to the exposure-orbit numbering in place originally. (b) schedule Visit 01 in the 2007 314 opportunity, and Visit 02 in the 2007 349 slot that offer good phase coverage of the transits. The only error/warning arises from the "restricted" category use. Resubmission 10/01/07 with V02 orbits 2 and 3 restored to standard length, orbit 4 kept trimmed by 3.5 minutes. ----- Attempting Submission 2 (Thu Sep 27 14:42:12 GMT 2007) ----- Phase II Proposal 11306 (11306.apt) successfully submitted. ----- Attempting Submission 3 (Thu Sep 27 18:39:35 GMT 2007) ----- Phase II Proposal 11306 (11306.apt) successfully submitted. ----- Attempting Submission 4 (Mon Oct 01 11:36:53 GMT 2007) ----- This is a test resubmission with Visit 02 orbits 2 and 3 restored to nominal full length, orbit 4 is kept at 3.5 minutes trimmed. Direct radius measurement of the Neptune-size transiting exoplanet GJ436b We propose to measure the radius of the first transiting Neptune-class extrasolar planet, GJ 436b. The transits of this 22-Earth-mass planet around a nearby M dwarf were recently detected by our team. Ground-based photometric observations indicate a planet size compatible with a Neptune-like structure or an "Ocean Planet". A direct radius determination from an HST infrared lightcurve will provide a much more direct measurement of the radius and density of the planet. GJ 436b is the nearest known transiting exoplanet, as well as the smallest and lightest, by a large margin. The high planet-to-star contrast in the infrared make it very favorable for detailed studies. NICMOS 1-2 microns observations, in addition to measuring its size, may reveal water absorption from its outer atmosphere.
We observe GJ 436 during 2 visits of 4 orbits each, attaining redundant coverage of the transit. Since the expected transit duration is 2/3 of an HST orbit and the target star can be seen for a little bit less than half of each orbit, two visits (with appropriate timing constraints) are required to obtain good phase coverage of the transit event. We will center the transit such that ingress or egress at the extreme limits are 1600s into the start of orbit 2, or 1600s before the end of orbit 4 respectively. This leaves at least about 60% of an orbit beyond the transit for establishing trends. We assume that stability will not have been achieved during orbit 1. We will use the NICMOS3 camera and grism G141. For HD 209458 at H = 6.36 we used moderate defocus with the NICMOS focus mechanism to smear the signal across 3-4 pixels instead of undersampling the line spread function. This allowed MULTIACCUM STEP1 NSAMP=4 exposures of 1.993 seconds to reach about half of saturation at peak. At H = 6.32 GJ 436 is nearly identical in brightness. We will adopt NSAMP = 4, again reaching nearly identical (to GO-9832) exposure levels. We will obtain about 250 exposures per HST orbit with a goal of having precisions in co-added 80s intervals of less than 0.0002.. Our observational approach for these observations is basically identical to the one used for the transit of HD 209458 in GO-9832. However, we now adopt the currently preferred means of achieving defocus of NICMOS following CAL/11335 -- see text in Additional Comments below. IMPLEMENTATION NOTES: the new parameter CAMERA-FOCUS=DEFOCUS and aperture NIC3-FIXD is used to place the NIC3 focus mechanism at -0.5mm and adjust the target placement in the aperture for the defocus respectively. Review of all potential scheduling windows has resulted in selection of two at 314:23 and 349:08 that yield best phase coverage of the transit event. The Phase II will contains BETWEENs restricting Visits 1 and 2 to these dates respectively, in the event that one or both of these opportunities cannot be used these would need modification. COOL STARS 3 false 0.0 false false false false false false RESTRICTED EXT-STAR M V-IV H = 6.32 J2000 11 42 11.0940 +26 42 23.65 J2000 NIC3 Spectroscopic No No G141 true /Users/gillil/go11306/OP-cache/11306-v01.xml Phase window made as wide as possible. A small subset of possible schedulings within this wide window would not be good for the science. We request access to the detailed draft schedule one month before execution to review the actual phase obtained, with the possibility of asking that the observations be delayed to a more opportune window. After access to these details Visit 1 is intended for Nov 11, 2007. This is selected with a BETWEEN, and a narrow phase window of +/-20 min is applied to guard against potential 1 orbit scheduling slips. (Tic-Visit :proposal-id 11306 :visit-id "01" :proposal-version -1 :trans-version "20070709" :date "27-Sep-2007 09:48:11.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 5387984 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11306 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11306 :visit-id "01" :obset-id "A1" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11306 :visit-id "01" :obset-id "B1" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11306 :visit-id "01" :obset-id "C1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11306 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2721 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11306 :visit-id "01" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2790 :al-overhead-at-end 0 :internal-dur-at-end 124 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11306 :visit-id "01" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2790 :al-overhead-at-end 0 :internal-dur-at-end 127 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11306 :visit-id "01" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 121 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) true 4 0 POS TARG +2.6, -11.6 moves the filter image to the position reached (approx 141,70) in GO-9832 moving the grism spectrum to a rather clean area of NIC3. Note that the new CAMERA-FOCUS=DEFOCUS parameter is used to defocus NIC3 to -0.5mm and the aperture NIC3-FIXD adjusts the target position for the defocus. Without defocus this would saturate slightly, should be fine here. This is the single direct image per visit allowing specification of wavelengths in the grism exposures. Starting with 10 exps at what will become standard exposure. Starting a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Ending orbit number 1 with sequence at standard multiaccum. This yields 1.993 s exposures and expected levels about half of saturation in the defocused G141 spectra. Orbit 2 with sequence at standard multiaccum. This yields 1.993 s exposures and expected levels about half of saturation in the defocused G141 spectra. Orbit 3 with sequence at standard multiaccum. This yields 1.993 s exposures and expected levels about half of saturation in the defocused G141 spectra. Last orbit, 4, with sequence at standard multiaccum. This yields 1.993 s exposures and expected levels about half of saturation in the defocused G141 spectra. true /private/tmp/OPVisit28777.xml Phase window made as wide as possible. A small subset of possible schedulings within this wide window would not be good for the science. We request access to the detailed draft schedule one month before execution to review the actual phase obtained, with the possibility of asking that the observations be delayed to a more opportune window. After inspecting draft schedule Visit 2 has been restricted to execute on the Dec 15, 2007 opportunity. This is forced with use of BETWEENs, and to guard against potential slip of 1 orbit in final scheduling a narrow phase window of +/-20 minutes is used. (Tic-Visit :proposal-id 11306 :visit-id "02" :proposal-version -1 :trans-version "20070709" :date "01-Oct-2007 07:26:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 5288592 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11306 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11306 :visit-id "02" :obset-id "A2" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11306 :visit-id "02" :obset-id "B2" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11306 :visit-id "02" :obset-id "C2" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11306 :visit-id "02" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2721 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11306 :visit-id "02" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2790 :al-overhead-at-end 0 :internal-dur-at-end 124 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11306 :visit-id "02" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2790 :al-overhead-at-end 0 :internal-dur-at-end 127 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11306 :visit-id "02" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2581 :al-overhead-at-end 0 :internal-dur-at-end 127 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) true 4 0 POS TARG +2.6, -11.6 moves the filter image to the position reached (approx 141,70) in GO-9832 moving the grism spectrum to a rather clean area of NIC3. Note that the new CAMERA-FOCUS=DEFOCUS parameter is used to defocus NIC3 to -0.5mm and the aperture NIC3-FIXD adjusts the target position for the defocus. Without defocus this would saturate slightly, should be fine here. This is the single direct image per visit allowing specification of wavelengths in the grism exposures. Starting with 10 exps at what will become standard exposure. Starting a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Continuing a sequence of expsoures during first orbit only that use NSAMP = 7 and 6 to yield exposure times that bracket the 1.993 s of standard STEP1 at NSAMP=4. These will be used for linearity self-consistency checks. Ending orbit number 1 with sequence at standard multiaccum. This yields 1.993 s exposures and expected levels about half of saturation in the defocused G141 spectra. Orbit 2 with sequence at standard multiaccum. This yields 1.993 s exposures and expected levels about half of saturation in the defocused G141 spectra. Orbit 3 with sequence at standard multiaccum. This yields 1.993 s exposures and expected levels about half of saturation in the defocused G141 spectra. Last orbit, 4, with sequence at standard multiaccum. This yields 1.993 s exposures and expected levels about half of saturation in the defocused G141 spectra.