We propose observations with HST/FGS to estimate the astrometric elements (perturbation orbit semi-major axis and inclination) of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information (McArthur et al. 2004), allowing us to determine companion masses. Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

We propose to obtain a group of observations (a group is six data sets = six orbits) at two epochs in Cycle 14 and one epoch in Cycle 15 to space the observations over a time span of about a year. Each group will be secured within two weeks. We have planned for the worst-case scenario, 2-gyro pointing control. Co-I Harrison will obtain classification spectra and BVRI photometry for all reference stars. Co-I Patterson will obtain Washington-DDO photometry to confirm reference star luminosity class. We essentially model a volume of space when carrying out this astrometry. The more prior information we have about our reference frame, the more accurate our final result. 12 false 0.0 false false false false false SUPPORTED STAR K III-I J2000 00 00 0.0000 +00 00 0.00 J2000 STAR F3-F9 J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR K V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 STAR G V-IV J2000 00 00 0.0000 +00 00 0.00 J2000 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 (Tic-Visit :proposal-id 10610 :visit-id "43" :proposal-version -1 :trans-version "20050717" :date "10-Nov-2005 13:07:43.0" :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 10610 :visit-id "43" :obset-id "43" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10610 :visit-id "43" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2689 :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 3169 :pcs-gap 0 ) false 1 0 (Tic-Visit :proposal-id 10610 :visit-id "44" :proposal-version -1 :trans-version "20050717" :date "10-Nov-2005 13:08:06.0" :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 10610 :visit-id "44" :obset-id "44" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10610 :visit-id "44" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2689 :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 3169 :pcs-gap 0 ) false 1 0 (Tic-Visit :proposal-id 10610 :visit-id "45" :proposal-version -1 :trans-version "20050717" :date "10-Nov-2005 13:08:18.0" :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 10610 :visit-id "45" :obset-id "45" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10610 :visit-id "45" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2689 :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 3169 :pcs-gap 0 ) false 1 0 (Tic-Visit :proposal-id 10610 :visit-id "46" :proposal-version -1 :trans-version "20050717" :date "10-Nov-2005 13:08:28.0" :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 10610 :visit-id "46" :obset-id "46" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10610 :visit-id "46" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2689 :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 3169 :pcs-gap 0 ) false 1 0 (Tic-Visit :proposal-id 10610 :visit-id "47" :proposal-version -1 :trans-version "20050717" :date "10-Nov-2005 13:08:37.0" :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 10610 :visit-id "47" :obset-id "47" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10610 :visit-id "47" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2689 :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 3169 :pcs-gap 0 ) false 1 0 (Tic-Visit :proposal-id 10610 :visit-id "48" :proposal-version -1 :trans-version "20050717" :date "10-Nov-2005 13:08:46.0" :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 10610 :visit-id "48" :obset-id "48" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10610 :visit-id "48" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2689 :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 3169 :pcs-gap 0 ) false 1 0 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 false -1 -1 (Tic-Visit :proposal-id 10610 :visit-id "78" :proposal-version -1 :trans-version "20060619" :date "30-Aug-2006 14:40:51.0" :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 10610 :visit-id "78" :obset-id "78" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10610 :visit-id "78" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2521 :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 3283 :pcs-gap 0 ) true 1 0