We are proposing for spatially resolved ACS+HRC observations of 11 very low mass binaries spanning late-M, L and T spectral types in order to obtain precise effective temperature measurements for each component. All of our targets are part of a program in which we are measuring dynamical masses of very low-mass binaries to an unprecedented precision of 10% (or better). However, without precise temperature measurements, the full scientific value of these mass measurements cannot be realized. Together, mass and temperature measurements will allow us to distinguish between brown dwarf evolutionary models that make different assumptions about the interior and atmospheric structure of these ultra-cool objects. While dynamical masses can be obtained from the ground in the near-IR, obtaining precise temperatures require access to optical data which, for these sub-arcsecond binaries, can only be obtained from space with Hubble.

Our target list contains 11 brown dwarf binaries with projected separations between 0.05 and 0.2 seconds of arc. Each binary will be observed with ACS/HRC (WFP3 if ACS is not available) and 3 filters: F625W, F775W, and F850LP. For several of our brighter targets, F892N and F658N will also be selected. Exposure times have been determined with the ETC to maximize signal-to-noise while avoiding saturation. For each filter, a 4-position box dither pattern will be used to minimize the impact of bad pixels and cosmic ray events. One of our targets (2MASS0920) should be observed before April, 2009 in insure the binary separation can be resolved with ACS/HRC. Also, target HD130948A, is bright and requires coronagraphic imaging. See target specific comments and coments in visit 11 for more details. COOL STARS 12 false 0.0 0.0 false false false false false SUPPORTED STAR BROWN DWARF J2000 00 27 55.9300 +22 19 32.80 J2000 STAR BROWN DWARF J2000 15 34 49.8000 -29 52 27.00 J2000 STAR BROWN DWARF J2000 18 47 3.4200 +55 22 43.30 J2000 STAR BROWN DWARF J2000 17 50 12.9100 +44 24 4.30 J2000 STAR BROWN DWARF J2000 21 40 29.3200 +16 25 18.30 J2000 STAR BROWN DWARF J2000 22 06 22.8000 -20 47 5.90 J2000 STAR BROWN DWARF J2000 04 21 49.0000 +19 29 10.00 J2000 STAR BROWN DWARF J2000 09 20 12.2000 +35 17 42.00 J2000 STAR BROWN DWARF J2000 10 47 12.6500 +40 26 43.70 J2000 STAR BROWN DWARF J2000 11 21 49.2500 -13 13 8.40 J2000 STAR BROWN DWARF G V-IV B-V=0.5 J2000 14 50 15.8000 +23 54 42.60 J2000 ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP ACS/HRC Imaging No No F625W ACS/HRC Imaging No No F775W ACS/HRC Imaging No No F850LP POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 1 false The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "01" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:14:33.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 91536 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2922 :al-overhead-at-end 40 :internal-dur-at-end 139 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3258 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "02" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:14:36.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2929 :al-overhead-at-end 40 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3267 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11605 :visit-id "02" :orbit-number 2 :pcs-time 195 :si-vis-utilization 3067 :al-overhead-at-end 40 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3267 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "03" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:14:40.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 109840 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3166 :al-overhead-at-end 40 :internal-dur-at-end 159 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3517 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "04" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:14:44.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 91536 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3002 :al-overhead-at-end 40 :internal-dur-at-end 139 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "05" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:14:48.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 91536 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "05" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2922 :al-overhead-at-end 40 :internal-dur-at-end 139 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "06" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:14:52.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 91536 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "06" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2922 :al-overhead-at-end 40 :internal-dur-at-end 139 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3258 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "07" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:14:55.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 91536 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "07" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2922 :al-overhead-at-end 40 :internal-dur-at-end 139 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. In this visit, target 2MASS0920 should be observed in March/April 2010 in order for the binary to be resolved by ACS/HRC. (Tic-Visit :proposal-id 11605 :visit-id "08" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:14:58.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "08" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2967 :al-overhead-at-end 40 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3310 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "09" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:15:02.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 91536 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "09" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3002 :al-overhead-at-end 40 :internal-dur-at-end 139 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "10" :proposal-version -1 :trans-version "20090130" :date "22-Jun-2009 07:15:04.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "10" :obset-id "10" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "10" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2911 :al-overhead-at-end 40 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11605 :visit-id "11" :proposal-version -1 :trans-version "20090130" :date "26-Jun-2009 12:47:51.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 36624 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11605 :visit-id "11" :obset-id "11" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11605 :visit-id "11" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2836 :al-overhead-at-end 38 :internal-dur-at-end 79 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3236 :pcs-gap 0 ) false 1 0