Binaries are the key to learning many crucial bulk properties of transneptunian objects (TNOs) including their masses. Perhaps the most interesting mass-dependent property of a TNO is its bulk density, which provides unique information about its bulk composition and interior structure. Densities have so far only been measured for a handful of binary TNO systems. This proposal seeks to determine orbits and thus masses of two more binary TNOs, both of which are also to be observed at thermal infrared wavelengths by the Herschel spacecraft. Combining the masses from Hubble with the sizes from Herschel will enable us to compute their densities. We will also obtain multi-wavelength photometric colors of the individual components of each binary system. It is imperative to link colors to the physical properties measurable in binary systems in order to use the remnant planetesimals in today's Kuiper belt to learn more about the early history of our own solar system, and more generally about how planetesimals form in nebular disks and subsequently evolve.

Strategically timed HST observations of binary TNOs which are also being observed by Herschel. The job of HST is to obtain relative astrometry, from which we determine the mutual orbits of the binary bodies, giving us their masses. Meanwhile, Herschel deterines their surface areas. When we put these pieces of information together, we get the bulk densities. Since we don't know the orbital periods a priori, we start with an initial pair of observations, then use Monte Carlo routines to work out optimal times for follow up observations. The visits to be scheduled this way start off being "on hold" until we give the go-ahead (in consultation with Tony Roman to ensure that they have a low impact on the scheduling team). SOLAR SYSTEM 12 false 0.0 0.0 false false false false SUPPORTED SOLAR SYSTEM ASTEROID SCATEXTD TYPE=ASTEROID,A=45.942227059000,E=0.143111631330,I=21.5221639250,O=184.180524020000,W=181.348001590000,M=261.218649180000,EQUINOX=J2000,EPOCH=18-JUN-2009:00:00:00 EARTH SOLAR SYSTEM ASTEROID COLD_CLASSICAL TYPE=ASTEROID,A=43.870431820000,E=0.087743329425,I=2.87015162560,O=118.070765340000,W=77.911465136000,M=325.997912140000,EQUINOX=J2000,EPOCH=18-JUN-2009:00:00:00 EARTH WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F438W WFC3/UVIS Imaging No No F606W WFC3/IR Imaging No No F110W WFC3/UVIS Imaging No No F606W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F438W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F438W WFC3/UVIS Imaging No No F606W WFC3/IR Imaging No No F110W WFC3/UVIS Imaging No No F606W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F438W POS-TARG DITHER 0.145 LINE false false 2 46.84 WFC3-UVIS-DITHER-LINE 1 false POS-TARG DITHER 0.636 LINE false false 2 41.788 WFC3-IR-DITHER-LINE 2 false Using ephemeris for target 12237-01-174567 Timing link suitability includes constraints ([02 After 01 by 1.2 to 1.8 days]) The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. It's good to do the first visit to a particular target early in the observability window, in order to leave as much time as possible for follow-ups (this is because we don't yet know the period, so we don't yet know the optimal times for the follow-ups). Hence the timing requirement for visit 01. If this turns out to be too restrictive, we can absolutely relax it. If you forsee any problems with this, let's iterate. 1283229362000 96.62095268260742 (Tic-Visit :proposal-id 12237 :visit-id "01" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 13:00:42.0" :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 12237 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 79 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 0 Using ephemeris for target 12237-02-174567 Timing link suitability includes constraints ([02 After 01 by 1.2 to 1.8 days]) The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1283344218000 96.62086880592051 (Tic-Visit :proposal-id 12237 :visit-id "02" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 13:01:15.0" :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 12237 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 79 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 0 Using ephemeris for target 12237-03-174567 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1285590012000 88.44556462465363 (Tic-Visit :proposal-id 12237 :visit-id "03" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 12:59:18.0" :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 309136 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12237 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 376 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) false 1 0 Pending observer input Using ephemeris for target 12237-04-174567 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1310237100000 105.0 (Tic-Visit :proposal-id 12237 :visit-id "04" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 13:00:04.0" :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 309136 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12237 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 376 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 0 Pending observer input Using ephemeris for target 12237-05-174567 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12237 :visit-id "05" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 13:02:58.0" :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 36624 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12237 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "05" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 79 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) false 1 0 Pending observer input Using ephemeris for target 12237-06-2005EF298 Timing link suitability includes constraints ([07 After 06 by 6.5 to 8.5 days]) The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. It's good to do the first visit to a particular target early in the observability window, in order to leave as much time as possible for follow-ups (this is because we don't yet know the period, so we don't yet know the optimal times for the follow-ups). Hence the timing requirement for visit 06. If this turns out to be too restrictive, we can absolutely relax it. If you forsee any problems with this, let's iterate. 1300581957000 115.91695997724958 (Tic-Visit :proposal-id 12237 :visit-id "06" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 13:03:00.0" :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 12237 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "06" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 79 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 0 Using ephemeris for target 12237-07-2005EF298 Timing link suitability includes constraints ([07 After 06 by 6.5 to 8.5 days]) The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1301253532000 114.74850631952239 (Tic-Visit :proposal-id 12237 :visit-id "07" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 13:03:02.0" :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 36624 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12237 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "07" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 79 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 0 Using ephemeris for target 12237-08-2005EF298 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1303472207000 96.85018895334412 (Tic-Visit :proposal-id 12237 :visit-id "08" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 13:04:13.0" :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 309136 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12237 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "08" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 376 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) false 1 0 Pending observer input Using ephemeris for target 12237-09-2005EF298 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1310151194000 110.48967419017958 (Tic-Visit :proposal-id 12237 :visit-id "09" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 13:04:19.0" :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 309136 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12237 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "09" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 376 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 0 Pending observer input Using ephemeris for target 12237-10-2005EF298 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1305044185000 112.48984709980527 (Tic-Visit :proposal-id 12237 :visit-id "10" :proposal-version -1 :trans-version "20100505" :date "08-Jul-2010 13:03:07.0" :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 12237 :visit-id "10" :obset-id "10" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12237 :visit-id "10" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2892 :al-overhead-at-end 0 :internal-dur-at-end 79 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) false 1 0 Pending observer input