We propose to complete the spatial velocity measurements of the stars in the central region of the remnant of SN 1572, one of the historical Galactic Type Ia supernovae. A new visit with WFPC2 would allow us to significantly improve the accuracy of the proper motion measurements of the stars in the field, since we would benefit from a long temporal baseline by using the WFPC2 images previously taken. This unique legacy would complement the high-precision ground-based observations made for the stars in the SN 1572 field during the past ten years. The search for the companion star of Galactic Type Ia supernovae, based on their high peculiar velocity as a salient feature, has already pointed to a good candidate for SN 1572. The current uncertainties in the tangential velocity of the candidate star and the other stars in the field can be reduced to less than a half with a visit in Cycle 16. This would lead to a precise determination of the parameters of the binary system that gave rise to the supernova. If not done during Cycle 16, the long temporal baseline for SN 1572 with WFPC2 would be lost.

Reobservation of Cycle 12 images ISM AND CIRCUMSTELLAR MATTER 12 false 0.0 false false false false false false SUPPORTED STAR SUPERNOVA TYPE IA J2000 00 25 18.5000 +64 08 8.60 J2000 STAR SUPERNOVA TYPE IA J2000 00 25 18.5000 +64 08 8.60 J2000 WFPC2 Imaging No F555W POS-TARG DITHER 0.559017 LINE 0.559017 false false 143.130096 4 26.56505 WFPC2-BOX 1 false POS-TARG DITHER 0.3535 LINE false false 2 45 WFPC2-LINE 2 false (Tic-Visit :proposal-id 11114 :visit-id "01" :proposal-version -1 :trans-version "20070326" :date "11-May-2007 00:49:19.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 896320 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11114 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11114 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2720 :al-overhead-at-end 100 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3243 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11114 :visit-id "01" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2700 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3243 :pcs-gap 0 ) false 2 0 (Tic-Visit :proposal-id 11114 :visit-id "01" :proposal-version -1 :trans-version "20070326" :date "11-May-2007 00:49:19.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 896320 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11114 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11114 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2720 :al-overhead-at-end 100 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3243 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11114 :visit-id "01" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2700 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3243 :pcs-gap 0 ) false 2 0