T dwarfs are excellent laboratories to study the evolution and the atmospheric physics of both brown dwarfs and extrasolar planets. To date, only a single T dwarf binary has a dynamical mass determination, and more are sorely needed. The prospects of measuring more dynamical masses over the next decade are limited to 6 known short-period T dwarf binaries. We propose here to obtain Long-Term HST/ACS monitoring for the 3 of the 6 binaries which cannot be resolved with AO from the ground. Upon completion, our program will substantially increase the number of T dwarf dynamical mass measurements and thereby provide key benchmarks for testing theoretical models of ultracool objects. Orbital monitoring of 3 methane brown dwarf (T dwarf) binaries. This is a long-term program with 6 epochs of imaging per target over 3 years. Cycle 19 is the final year of this program, and the BETWEEN requirements are set by the need to have each binary's observation epochs be separated by at least ~4 months as justified in the original Phase 1 proposal. According to the latest scheduling information available for our Cycle 18 visits as of this Phase 2 submission, all 3 of our targets will be observed between August and October of 2011. Thus, we will obtain new data in the spring and fall of 2012. COOL STARS 12 false 0.0 0.0 false false false false SUPPORTED STAR BROWN DWARF This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 J=14.5, H=13.5, K=12.9 STAR BROWN DWARF This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 J=16.0, H=14.8, K=14.2 STAR BROWN DWARF This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 J=15.9, H=15.3, K=15.5 ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W ACS/HRC Imaging No No F814W POS-TARG DITHER 3.011 LINE false false 2 85.28 ACS-WFC-DITHER-LINE 1 false POS-TARG DITHER 0.364 LINE false true 2 47.23 ACS-WFC-DITHER-LINE 8 false POS-TARG DITHER 0.265 LINE 0.187 false false 69.05 4 20.67 ACS-WFC-DITHER-BOX 7 false The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. 1329452041000 77.2681345305241 (Tic-Visit :proposal-id 12661 :visit-id "01" :proposal-version -1 :trans-version "20110509" :date "07-Jul-2011 17:44:42.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 106672 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12661 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12661 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2898 :al-overhead-at-end 0 :internal-dur-at-end 155 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) false 1 0 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. 1346300201000 261.2785494361129 (Tic-Visit :proposal-id 12661 :visit-id "02" :proposal-version -1 :trans-version "20110509" :date "07-Jul-2011 17:44:50.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 106672 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12661 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12661 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2898 :al-overhead-at-end 0 :internal-dur-at-end 155 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) false 1 0 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. 1329021536000 65.28855804756881 (Tic-Visit :proposal-id 12661 :visit-id "03" :proposal-version -1 :trans-version "20110509" :date "07-Jul-2011 17:04:29.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 568448 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12661 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12661 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2924 :al-overhead-at-end 0 :internal-dur-at-end 349 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) false 1 0 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. 1345944458000 253.72275419754232 (Tic-Visit :proposal-id 12661 :visit-id "04" :proposal-version -1 :trans-version "20110509" :date "07-Jul-2011 17:04:30.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 568448 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12661 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12661 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2924 :al-overhead-at-end 0 :internal-dur-at-end 349 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) false 1 0 (Tic-Visit :proposal-id 12661 :visit-id "54" :proposal-version -1 :trans-version "20120802" :date "25-Sep-2012 10:24:06.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 568448 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12661 :visit-id "54" :obset-id "54" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12661 :visit-id "54" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2924 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3253 :pcs-gap 0 ) true 1 1 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. 1333773195000 102.19579705290562 (Tic-Visit :proposal-id 12661 :visit-id "05" :proposal-version -1 :trans-version "20110509" :date "07-Jul-2011 17:04:30.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 568448 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12661 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12661 :visit-id "05" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3178 :al-overhead-at-end 0 :internal-dur-at-end 349 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3511 :pcs-gap 0 ) false 1 0 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12661 :visit-id "06" :proposal-version -1 :trans-version "20110509" :date "07-Jul-2011 17:04:31.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 568448 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12661 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12661 :visit-id "06" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3178 :al-overhead-at-end 0 :internal-dur-at-end 349 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3511 :pcs-gap 0 ) false 1 0