We propose to observe the brightest transiting exoplanet systems, HD 209458b and HD 189733b, during both primary eclipse (transit) and secondary eclipse (when the planet is behind the star). A successful measurement would result in the spectral characterization of both dayside and nightside thermal emission. This, in turn, would result in several important determinations, including (1) the temperature of the dayside, (2) the temperature of the nightside, (3) the probable detection of water, (4) strong constraints on the presence or absence of clouds, and (5) constraints on models of atmospheric transport between the day and night sides. Our selected wavelength region of 1.4 to 2.4 microns includes the two most prominent predicted features (water) in models for hot Jupiter emission. For these observations, we propose to use the NICMOS 3 grism and selected narrow band filters in a carefully designed, differential observation intended to achieve a dynamic range of 10,000:1. Our proposed observations are uniquely enabled by HST, which alone has the combination of stability, sensitivity, wavelength coverage, and dynamic range to make these high-impact observations possible.

Visits: 3 each consisting of either 3 or 4 consecutive HST orbits. In each visit, either the second or or third orbit observing observing interval is phased to start at approximately the onset of the secondary eclipse or transit events. The visits each end with observations using a narrow band filter for wavelength calibration. All remaining time in the orbtis consistes of repeated 2s exopsures using one of the NICMOS 206 and 141 grisms. All observations need to be conducted at the same role angle. Additionally, there should be no role angle moves during a given visit. IMPLEMENTATION NOTES: 1) Manual deletion of some NICMOS HOME alignment is necessary 2) Must force the creation of a final HOME 3) May need to extend the Phase Critical window this schedules in This proposal uses standard NICMOS ALIGN exposures to cause a defocus for the observations. The desire is to defocus, perform all science exposures and then return (HOME) to normal focus at the end. For the defocus the mechanisms are to be placed, in absolute terms, in the same positions as the first ALIGN exposure in the NIC3 visits of the NICMOS Focus Monitor. The Focus Monitor uses special commanding and ALIGN exposures to manage the NIC mechanisms while this proposal uses only ALIGN exposures, no special commanding. It is necessary to translate the ALIGN parameters in the Focus Monitor into a usable set for this proposal because the two proposals reference different zero points for determining the mechanism motions. The ALIGN optional parameter values in the Focus monitor are relative to mechanical zero where as this proposal must use values based on the nominal NIC3 zero points. Mechanical Zero for the Focus and X & Y tilts is (0, 4, 9) respectively and, at the time of this proposal, the nominal NIC3 zero points are (-8636, -10, -5). The "Focus Monitor (-455, -1, -1) from the Mech Zero points" yields an absolute position of (-455, 3, 8) which can be achieved by using "(+8181, +13, +13) from the Nominal NIC3 Zero points" for this proposal. Due to the usage of the PHASE and NEW OBSET special requirements in this proposal, TRANS will create a HOME which occurs immediately after the ALIGN and would cause the observation to execute at nominal focus, not at the desired defocus. Additionally, TRANS will not create a final HOME because it thinks it already HOMEd the mechanisms. These issues are resolved by using an ALIGN exposure at the very end to force TRANS to create a final HOME and then manually deleting any HOME(s) that occurs between the first ALIGN exposure and this forcebly created final HOME. This allows the mechanisms to stay at the defocus position during all science exposures and then returns them to their nominal focus positions at the very end. See the exposure level comments in the last ALIGN exposure of each visit. STAR FORMATION 12 false 0.0 false false false false false false SUPPORTED STAR K III-I This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 20 00 43.7133 +22 42 39.07 J2000 NIC3 Spectroscopic No No G206 NIC3 Imaging No No F190N NIC3 Imaging No No F215N NIC3 Spectroscopic No No G206 NIC3 Imaging No No F190N NIC3 Imaging No No F215N NIC3 Spectroscopic No No G206 NIC3 Imaging No No F190N NIC3 Imaging No No F215N NIC3 Spectroscopic No No G206 NIC3 Imaging No No F190N NIC3 Imaging No No F215N start 189733 day g206 spectra - visit is 5 orbits long with secondary eclipse observed in orbit 3 - constraint: role angle held constant (Tic-Visit :proposal-id 10855 :visit-id "01" :proposal-version -1 :trans-version "20070325" :date "11-Apr-2007 07:30:38.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 6357328 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10855 :visit-id "01" :obset-id "01" :pcs-mode "GYRO" ) (Tic-Obset :proposal-id 10855 :visit-id "01" :obset-id "A1" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 10855 :visit-id "01" :obset-id "B1" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 10855 :visit-id "01" :obset-id "C1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10855 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2650 :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 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10855 :visit-id "01" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2788 :al-overhead-at-end 0 :internal-dur-at-end 105 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10855 :visit-id "01" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2697 :al-overhead-at-end 0 :internal-dur-at-end 148 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10855 :visit-id "01" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2726 :al-overhead-at-end 0 :internal-dur-at-end 148 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10855 :visit-id "01" :orbit-number 5 :pcs-time 355 :si-vis-utilization 2697 :al-overhead-at-end 0 :internal-dur-at-end 148 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) true 5 0 The FOCUS and XTILT, YTILT parameters defines the PAM focus setting for camera NIC3 at -0.5mm relative to mechanical zero. The use of these parameters assume that the PAM is at the nominal NIC3 position of -9.5mm, with FOCUS=-8636, XTILT=-10, YTILT=-5. The tilt moves as 1.4 steps/mm and the focus as 909.05 steps/mm. See special implementation notes in proposal level Additional Comments. This exposure is used to fake the system. It forces the creation of a final HOME alignment. Any HOME that occurs between the first ALIGN exposure and this created final HOME must be manually deleted. The focus value is purposely small to keep the duration of this exposure as short as possible and to let the HOME perform the job of returning the mechanisms to their nominal positions. NOTE: That while this exposure says to move the focus -1 step from the nominal zero point (-8636 - 1), the actual execution will, due to deleting the HOME(s), be -1 step from the current position (-455 - 1). Meaning the absolute position after this move will be far different than the absolute position this exposure seems to request. You must verify that this move will not violate limits and/or damage the mechanisms. start 189733 night g206 spectra - visit is 5 orbits long with secondary transit observed in orbit 3 - constraint: role angle held constant (Tic-Visit :proposal-id 554 :visit-id "03" :proposal-version -1 :trans-version "20070325" :date "09-Apr-2007 12:28:04.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 6357328 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 554 :visit-id "03" :obset-id "03" :pcs-mode "GYRO" ) (Tic-Obset :proposal-id 554 :visit-id "03" :obset-id "A3" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 554 :visit-id "03" :obset-id "B3" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 554 :visit-id "03" :obset-id "C3" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 554 :visit-id "03" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2650 :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 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 554 :visit-id "03" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2788 :al-overhead-at-end 0 :internal-dur-at-end 105 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 554 :visit-id "03" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2697 :al-overhead-at-end 0 :internal-dur-at-end 148 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 554 :visit-id "03" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2726 :al-overhead-at-end 0 :internal-dur-at-end 148 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) (Tic-Orbit :proposal-id 554 :visit-id "03" :orbit-number 5 :pcs-time 355 :si-vis-utilization 2697 :al-overhead-at-end 0 :internal-dur-at-end 148 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3147 :pcs-gap 0 ) false 5 0 The FOCUS and XTILT, YTILT parameters defines the PAM focus setting for camera NIC3 at -0.5mm relative to mechanical zero. The use of these parameters assume that the PAM is at the nominal NIC3 position of -9.5mm, with FOCUS=-8636, XTILT=-10, YTILT=-5. The tilt moves as 1.4 steps/mm and the focus as 909.05 steps/mm. See special implementation notes in proposal level Additional Comments. This exposure is used to fake the system. It forces the creation of a final HOME alignment. Any HOME that occurs between the first ALIGN exposure and this created final HOME must be manually deleted. The focus value is purposely small to keep the duration of this exposure as short as possible and to let the HOME perform the job of returning the mechanisms to their nominal positions. NOTE: That while this exposure says to move the focus -1 step from the nominal zero point (-8636 - 1), the actual execution will, due to deleting the HOME(s), be -1 step from the current position (-455 - 1). Meaning the absolute position after this move will be far different than the absolute position this exposure seems to request. You must verify that this move will not violate limits and/or damage the mechanisms.