Edited #1 142942117 Assigned ID: 856 ----- Attempting Submission 1 (Fri Apr 10 21:22:28 GMT 2015) ----- HST Phase I Proposal 856 (indivmass-no0926.apt) successfully submitted. Receipt: # 856-1 ----- Attempting Submission 2 (Fri Apr 10 23:38:06 GMT 2015) ----- Corrected aperture from UVIS-CENTER to UVIS for Visits 01-07. Changed exposure times in Visit 08 to avoid saturation and correspondingly switched to subarray C512C. -260733667 ----- Attempting Submission 1 (Sun Jul 19 09:00:02 GMT 2015) ----- HST Phase II Proposal 14220 (go14220.apt) successfully submitted. Receipt: # 14220-1 ----- Attempting Submission 2 (Mon Jul 20 00:07:24 GMT 2015) ----- ----- Attempting Submission 3 (Wed Oct 07 20:25:43 GMT 2015) ----- Mapping the Substellar Mass-Luminosity Relation Down to the L/T Transition Substellar models underpin our theoretical understanding of brown dwarfs and gas-giant exoplanets, so assessing their accuracy is paramount. The past several years have seen progress in testing models thanks to a growing number of dynamical (total) masses for brown dwarf binaries determined via (relative) orbit monitoring from ground-based AO. However, the strongest tests of models require individual masses, particularly for calibrating the mass-luminosity relation. This is poorly constrained over the range of spectral types most influenced by clouds (mid-L to early-T). Given the observed prevalence of clouds in the atmospheres of directly imaged planets, testing models at such temperatures is crucial. We propose a 3-year program to obtain individual masses for a sample of 11 substellar binaries. Our proposal builds on nearly a decade of orbital monitoring from the ground to measure dynamical total masses. Our goal is thus to measure precise mass ratios, utilizing HST's unique wide-field, high-angular resolution astrometric capabilities. We will obtain WFC3-UVIS images capturing our targets and numerous reference stars so that we can measure the relative amount of orbital motion in each component to determine mass ratios. Three of our targets have I-band photocenter orbits measured at USNO and VLT and thus only require one epoch of resolved I-band imaging to unlock individual masses. We will use this first large sample of substellar individual masses to map out the mass-luminosity relation over a wide range of temperatures (1000-2000 K) including the L/T transition. This will become a touchstone sample for tests of ultracool atmospheric models in the era of JWST. Our program consists of two distinct observing modes and accompanying goals. The primary one is to obtain absolute astrometry of the individual components of seven tight (<~0.1 arcsec) brown dwarf binaries that already have known relative orbits (and thereby total dynamical masses). Obtaining absolute astrometry at multiple epochs over 3 years will allow us to disentangle proper motion from the orbital motion of each component, and by measuring the ratio of component orbital motion will allow a precise measurement of the mass ratio and thus individual masses. The key observational goal is to obtain as high of precision absolute position measurements for as many reference stars as possible across all epochs. This motivates us to place our targets near the center of the full UVIS FOV, using the UVIS-CENTER aperture, so that data taken at different roll angles will share the maximum number of reference stars in common. We expect the dominant source of our astrometric errors will be set by how well we can deblend our tightest (~50 mas) binaries with flux ratios of ~1-2 mag. We expect positional errors on 4 mas in the most unfavorable cases. The second observing mode/goal is to image three astrometric binaries at a single epoch each in order to measure their optical flux ratios. Coincidentally, the optimal times to observe this sample result in one of these binaries being observed in each of Cycles 23, 24, and 25. Their photocenter orbits have previously been determined in seeing-limited optical imaging, so a single HST epoch will break the degeneracy between mass ratio and flux ratio, enabling individual mass measurements of both components. Thus our goal is high-precision relative photometry of these tight (50-100 mas) binaries, and we will use the UVIS2-C512C-CTE aperture to minimize image degradation caused by CTE losses. COOL STARS 12 false false false false SUPPORTED STAR L J2000 J2000 J=14.1 STAR L J2000 J2000 J=14.6 STAR L J2000 J2000 J=15.8 STAR L J2000 J2000 J=15.6 STAR L J2000 J2000 J=16.0 STAR T J2000 J2000 J=16.3 STAR L J2000 J2000 J=14.3 STAR M V-IV J2000 J2000 I=15.7 WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F814W POS-TARG DITHER 0.135 LINE false false 3 46.84 WFC3-UVIS-DITHER-LINE-3PT 1 false POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 2 false The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. /private/var/folders/7y/03gjt35n26316c2dtwnxll_w0000gn/T/OPVisit5947138439428819412.xml (Tic-Visit :proposal-id 14220 :visit-id "01" :proposal-version -1 :trans-version "20150609" :date "07-Oct-2015 10:24:52.0" :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 1732496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14220 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14220 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2885 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. /private/var/folders/7y/03gjt35n26316c2dtwnxll_w0000gn/T/OPVisit2163611868313135370.xml (Tic-Visit :proposal-id 14220 :visit-id "02" :proposal-version -1 :trans-version "20150609" :date "07-Oct-2015 10:24:54.0" :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 1732496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14220 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14220 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2933 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3267 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. /private/var/folders/7y/03gjt35n26316c2dtwnxll_w0000gn/T/OPVisit3186651793700492367.xml (Tic-Visit :proposal-id 14220 :visit-id "03" :proposal-version -1 :trans-version "20150609" :date "07-Oct-2015 10:24:56.0" :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 1732496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14220 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14220 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2885 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. /private/var/folders/7y/03gjt35n26316c2dtwnxll_w0000gn/T/OPVisit8207761852567374785.xml (Tic-Visit :proposal-id 14220 :visit-id "04" :proposal-version -1 :trans-version "20150609" :date "07-Oct-2015 10:24:57.0" :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 1732496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14220 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14220 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2933 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3267 :pcs-gap 0 ) true 1 0 /Users/tdupuy/prop/hst23/OP-cache/go14220-edit-v05.xml The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 14220 :visit-id "05" :proposal-version -1 :trans-version "20150609" :date "04-Oct-2015 13:07:49.0" :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 1732496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14220 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14220 :visit-id "05" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2933 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3267 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. /private/var/folders/7y/03gjt35n26316c2dtwnxll_w0000gn/T/OPVisit2667715897232323826.xml (Tic-Visit :proposal-id 14220 :visit-id "06" :proposal-version -1 :trans-version "20150609" :date "07-Oct-2015 10:24:59.0" :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 1732496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14220 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14220 :visit-id "06" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2885 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3221 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. /private/var/folders/7y/03gjt35n26316c2dtwnxll_w0000gn/T/OPVisit1317874687337159266.xml (Tic-Visit :proposal-id 14220 :visit-id "07" :proposal-version -1 :trans-version "20150609" :date "07-Oct-2015 10:25:01.0" :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 1732496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14220 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14220 :visit-id "07" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2885 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3221 :pcs-gap 0 ) true 1 0 /Users/tdupuy/prop/hst23/OP-cache/go14220-edit-v08.xml The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. 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