GJ 436b is the only known Neptune-mass transiting exoplanet. Like Neptune, more than 80% of the mass is ice and rock, surrounded by a thin H/He envelope of only 1-3 earth masses. The similarities end there, however, as GJ 436b orbits a mere 0.03 A.U. from its M dwarf primary and has a toasty 700 K atmosphere. Although it is much warmer than the gas giant planets in the solar system, GJ 436b is the coolest transiting planet discovered to date. As a result, we expect most of the carbon in GJ 436b's atmosphere to exist in the form of methane instead of the carbon monoxide found in the atmospheres of the hotter, more massive transiting planets. We propose to test this prediction by searching for the signature of water and methane absorption in this unusual planet's atmosphere as seen in the wavelength dependence of the transit depth from 1.4-2.5 micron. This wavelength range includes strong absorption bands from both water and methane, and will also allow us to place limits on the presence of clouds and atmospheric hazes if present. Using the technique of transit timing, these observations (which span four transits) will also allow us to search for additional planetary companions with masses as small as that of Mars. A second planet would provide a natural explanation for GJ 436b's ability to maintain a significant orbital eccentricity, despite the fact that the circularization time scale for this system is significantly shorter than its current age. Four transits of GJ 436b will be observing using the G141 grating on WFC3. Each visit will consist of four HST orbits, where the first orbit is discarded due to instrument settling, the second and fourth orbits establish an out-of-transit baseline, and the third orbit is roughly centered on the transit itself. In the first orbit we will obtain an image in F139M for wavelength specification, then switch to G141 for the remainder of the observations. We observe our target in drift scan mode, oriented to increase in the y (vertical) direction. EXTRA-SOLAR PLANETS 12 false 0.0 0.0 false false false false AVAILABLE STAR M V-IV This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 B-V=1.52, H=6.32, K=6.07 NIC3 Spectroscopic No No G206 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. First of four visits with WFC3. It is essential for the four orbits in each visit to be scheduled in a contiguous block. These orbits should be free of the SAA. The total allowed window for the start of each visit is 0.003 in planet orbital phase, corresponding to a 15 minute interval. In order to ensure complete coverage of the phase curve, the visits have been scheduled with two different offsets corresponding to either the first or second 7.5 minutes of this 15 minute window. However, if this poses a significant barrier to scheduling the requirements for individual visits may be relaxed to the full 15 minute range (0.9418-0.9458 in orbital phase). We also include orientation restrictions intended to avoid overlapping spectra with a H=13.1 star located at a distance of 64" (6"S, 63"W) from GJ 436 (H=6.3). We find that we should avoid rotation angles between -10 to +20 degrees and 170 to 200 degrees in order to preserve a minimum separation of 12" in the Y (vertical) direction between the two spectra. We use 2MASS J2000 coordinates for both objects, and take into account GJ 436b's high proper motion of [896.1, -813.5] mas/yr to calculate the J2012 coordinates and corresponding rotation angle constraints. 1335907285000 116.29305933669178 (Tic-Visit :proposal-id 11622 :visit-id "01" :proposal-version -1 :trans-version "20120802" :date "25-Sep-2012 16:16:21.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 436832 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11622 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11622 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2558 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2482 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3022 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3025 :al-overhead-at-end 0 :internal-dur-at-end 160 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3253 :pcs-gap 0 ) false 4 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. Second of four visits with WFC3. It is essential for the four orbits in each visit to be scheduled in a contiguous block. These orbits should be free of the SAA. The total allowed window for the start of each visit is 0.003 in planet orbital phase, corresponding to a 15 minute interval. In order to ensure complete coverage of the phase curve, the visits have been scheduled with two different offsets corresponding to either the first or second 7.5 minutes of this 15 minute window. However, if this poses a significant barrier to scheduling the requirements for individual visits may be relaxed to the full 15 minute range (0.9418-0.9458 in orbital phase). We also include orientation restrictions intended to avoid overlapping spectra with a H=13.1 star located at a distance of 64" (6"S, 63"W) from GJ 436 (H=6.3). We find that we should avoid rotation angles between -10 to +20 degrees and 170 to 200 degrees in order to preserve a minimum separation of 12" in the Y (vertical) direction between the two spectra. We use 2MASS J2000 coordinates for both objects, and take into account GJ 436b's high proper motion of [896.1, -813.5] mas/yr to calculate the J2012 coordinates and corresponding rotation angle constraints. Lastly, we include an additional downward offset of -6.5 arcsec in Y position for the second exposure to accound for the additional 6.5 second delay observed in the start of each exposure for Visit 1. This corresponds to a new Y offset of 1.5 - 6.5 = 5.0 arcsec. (Tic-Visit :proposal-id 11622 :visit-id "02" :proposal-version -1 :trans-version "20120802" :date "25-Sep-2012 16:00:36.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 436832 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11622 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11622 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2559 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2482 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3022 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3025 :al-overhead-at-end 0 :internal-dur-at-end 160 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3253 :pcs-gap 0 ) false 4 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. Third of four visits with WFC3. It is essential for the four orbits in each visit to be scheduled in a contiguous block. These orbits should be free of the SAA. The total allowed window for the start of each visit is 0.003 in planet orbital phase, corresponding to a 15 minute interval. In order to ensure complete coverage of the phase curve, the visits have been scheduled with two different offsets corresponding to either the first or second 7.5 minutes of this 15 minute window. However, if this poses a significant barrier to scheduling the requirements for individual visits may be relaxed to the full 15 minute range (0.9418-0.9458 in orbital phase). We also include orientation restrictions intended to avoid overlapping spectra with a H=13.1 star located at a distance of 64" (6"S, 63"W) from GJ 436 (H=6.3). We find that we should avoid rotation angles between -10 to +20 degrees and 170 to 200 degrees in order to preserve a minimum separation of 12" in the Y (vertical) direction between the two spectra. We use 2MASS J2000 coordinates for both objects, and take into account GJ 436b's high proper motion of [896.1, -813.5] mas/yr to calculate the J2012 coordinates and corresponding rotation angle constraints. Lastly, we include an additional downward offset of -6.5 arcsec in Y position for the second exposure to accound for the additional 6.5 second delay observed in the start of each exposure for Visit 1. This corresponds to a new Y offset of 1.5 - 6.5 = 5.0 arcsec. (Tic-Visit :proposal-id 11622 :visit-id "03" :proposal-version -1 :trans-version "20120802" :date "25-Sep-2012 16:01:25.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 436832 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11622 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11622 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2559 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2482 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3022 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "03" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3025 :al-overhead-at-end 0 :internal-dur-at-end 160 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3253 :pcs-gap 0 ) false 4 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. Fourth of four visits with WFC3. It is essential for the four orbits in each visit to be scheduled in a contiguous block. These orbits should be free of the SAA. The total allowed window for the start of each visit is 0.003 in planet orbital phase, corresponding to a 15 minute interval. In order to ensure complete coverage of the phase curve, the visits have been scheduled with two different offsets corresponding to either the first or second 7.5 minutes of this 15 minute window. However, if this poses a significant barrier to scheduling the requirements for individual visits may be relaxed to the full 15 minute range (0.9418-0.9458 in orbital phase). We also include orientation restrictions intended to avoid overlapping spectra with a H=13.1 star located at a distance of 64" (6"S, 63"W) from GJ 436 (H=6.3). We find that we should avoid rotation angles between -10 to +20 degrees and 170 to 200 degrees in order to preserve a minimum separation of 12" in the Y (vertical) direction between the two spectra. We use 2MASS J2000 coordinates for both objects, and take into account GJ 436b's high proper motion of [896.1, -813.5] mas/yr to calculate the J2012 coordinates and corresponding rotation angle constraints. Lastly, we include an additional downward offset of -6.5 arcsec in Y position for the second exposure to accound for the additional 6.5 second delay observed in the start of each exposure for Visit 1. This corresponds to a new Y offset of 1.5 - 6.5 = 5.0 arcsec. (Tic-Visit :proposal-id 11622 :visit-id "04" :proposal-version -1 :trans-version "20120802" :date "25-Sep-2012 16:14:57.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 436832 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11622 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11622 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2559 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "04" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2482 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "04" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3022 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "04" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3025 :al-overhead-at-end 0 :internal-dur-at-end 160 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3253 :pcs-gap 0 ) false 4 0 First of four visits with WFC3. It is essential for the four orbits in each visit to be scheduled in a contiguous block. These orbits should be free of the SAA. The total allowed window for the start of each visit is 0.003 in planet orbital phase, corresponding to a 15 minute interval. In order to ensure complete coverage of the phase curve, the visits have been scheduled with two different offsets corresponding to either the first or second 7.5 minutes of this 15 minute window. However, if this poses a significant barrier to scheduling the requirements for individual visits may be relaxed to the full 15 minute range (0.9418-0.9458 in orbital phase). We also include orientation restrictions intended to avoid overlapping spectra with a H=13.1 star located at a distance of 64" (6"S, 63"W) from GJ 436 (H=6.3). We find that we should avoid rotation angles between -10 to +20 degrees and 170 to 200 degrees in order to preserve a minimum separation of 12" in the Y (vertical) direction between the two spectra. We use 2MASS J2000 coordinates for both objects, and take into account GJ 436b's high proper motion of [896.1, -813.5] mas/yr to calculate the J2012 coordinates and corresponding rotation angle constraints. (Tic-Visit :proposal-id 11622 :visit-id "01" :proposal-version -1 :trans-version "20120802" :date "25-Sep-2012 16:16:21.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 436832 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11622 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11622 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2558 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2482 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3022 :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 3253 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11622 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3025 :al-overhead-at-end 0 :internal-dur-at-end 160 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3253 :pcs-gap 0 ) false 4 0