When it comes to fundamental properties of an astronomical object, it is difficult to think of a more fundamental physical property than its size. Because of their distance, objects in the Kuiper Belt are generally too small for their disks to be resolved. The heterogeneous albedo and color of the Kuiper Belt population makes size estimates from observed absolute magnitude highly uncertain. And the long-awaited data from the Spitzer Space Telescope suffers from our ignorance of crucial macro- and micro-physical properties such as spin period, pole orientation, surface roughness, and thermal inertia. We propose to add a new dimension to the measurement of KBO diameters by employing two techniques that will directly measure the diameters of three large KBOs. We expect to obtain diameter measurements with uncertainties of 10% or better and utilize these to validate and cross calibrate the growing web of diameter measurements for KBOs.

KBO diameter measurements SOLAR SYSTEM 12 false 0.0 false false false false false false SUPPORTED SOLAR SYSTEM ASTEROID Target RA and Dec are computed position of asteriod on 2007.073:15:00:00 UT. J2000 00 00 0.0000 +00 00 0.00 J2000 SOLAR SYSTEM ASTEROID scatnear TYPE=ASTEROID,A=45.569999523,E=0.15767069,I=28.9977173,O=79.6076492,W=295.547773,M=149.6158021,EQUINOX=J2000,EPOCH=19-JUL-2007:00:00:00 A_VEL KBO2005FY9 FROM EARTH GT 0.00005 SOLAR SYSTEM ASTEROID 3:2E TYPE=ASTEROID,A=39.275462007,E=0.22324539,I=20.5961319,O=268.7354534,W=72.3682649,M=162.9071722,EQUINOX=J2000,EPOCH=19-JUL-2007:00:00:00 SOLAR SYSTEM ASTEROID scatnear TYPE=ASTEROID,A=43.186994889,E=0.12455967,I=25.8451701,O=324.540242,W=339.2972565,M=62.4617255,EQUINOX=J2000,EPOCH=19-JUL-2007:00:00:00 SOLAR SYSTEM ASTEROID scatnear TYPE=ASTEROID,A=45.569999523,E=0.15767069,I=28.9977173,O=79.6076492,W=295.547773,M=149.6158021,EQUINOX=J2000,EPOCH=19-JUL-2007:00:00:00 A_VEL KBO2005FY9 FROM EARTH GT 0.00005 FGS TRANS No F605W ACS/HRC Imaging No No F555W ACS/HRC Imaging No No F555W ACS/HRC Imaging No No F555W (Tic-Visit :proposal-id 10801 :visit-id "01" :proposal-version -1 :trans-version "20060322" :date "16-May-2006 17:01:52.0" :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 331232 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10801 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10801 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2719 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 1 0 (Tic-Visit :proposal-id 10801 :visit-id "02" :proposal-version -1 :trans-version "20060322" :date "16-May-2006 17:02:05.0" :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 331232 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10801 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10801 :visit-id "02" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2719 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 1 0 (Tic-Visit :proposal-id 10801 :visit-id "03" :proposal-version -1 :trans-version "20060322" :date "16-May-2006 17:02:15.0" :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 331232 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10801 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10801 :visit-id "03" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2719 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 1 0 (Tic-Visit :proposal-id 10801 :visit-id "04" :proposal-version -1 :trans-version "20061210" :date "19-Jan-2007 14:34:43.0" :trans-errors '(:WARNINGS 4 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "05" :si-bright-earth-limb-angle 15.5 :data-volume 0 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10801 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10801 :visit-id "04" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2748 :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 3132 :pcs-gap 0 ) false 1 0 Visit added by PC to see when visit 4 could schedule, and find the coord of the asteroid on the day that visit is executed. This visit will be withdrawn after visit 4 executes. (Tic-Visit :proposal-id 10801 :visit-id "05" :proposal-version -1 :trans-version "20060322" :date "01-Jun-2006 07:18:52.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "05" :si-bright-earth-limb-angle 15.5 :data-volume 0 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10801 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10801 :visit-id "05" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2763 :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 3132 :pcs-gap 0 ) false 1 0