This is a simple proposal; no comments therefore. ----- Attempting Submission 1 (Tue May 08 20:58:40 GMT 2007) ----- There are very small overruns on all three orbits. To reduce these requires radical reduction of the exposure times since WFPC2 times are quantized. The schedulability of these observations is very broad; I hope the small overrun is not a problem. Crotts SN 2006X revision of former ACS proposal #613 Assigned ID: 1251 ----- Attempting Submission 1 (Fri Feb 09 14:24:16 GMT 2007) ----- Confirming Light Echoes from SN 2006X in M100 We propose a minimal investment of spacecraft time to discover and confirm a light echo from Supernova 2006X in M100, the closest Type Ia in many years. Our spectroscopic and photometric data indicate that this SN sits behind a large amount of interstellar dust likely to produce a strong echo signal. This is one of very few cases where we will be able to study the three-dimensional environment of a SN Ia in full detail, and begin to understand how environmental effects play into the evolutionary and observational factors which influence the utility of SN Ia as standard candles for probing cosmology. We propose an efficient program to definitively detect (or not) a light echo of reasonable signal strength, to confirm that it is an echo by demonstrating apparent superluminal motion if it exists, to map the three-dimensional geometry of the reflecting interstellar structures, and to detail the reflectance properties of the dust which can be used to constrain its grain size and composition distribution.
These observations recreate as closely as possible those of GO 10991 in 2006, consisting of short ACS exposures in three filters F435W, F555W and F775W. These are recreated by one orbit of F555W, one orbit of F380W and F439W, and one orbit of F702W and F791W. ISM IN EXTERNAL GALAXIES 0 false 0.0 false false false false false false SUPPORTED STAR SUPERNOVA TYPE IA J2000 12 22 53.9600 +15 48 32.20 J2000 WFPC2 Imaging No F791W WFPC2 Imaging No F702W WFPC2 Imaging No F555W WFPC2 Imaging No F439W WFPC2 Imaging No F380W WFPC2 Imaging No F791W WFPC2 Imaging No F555W WFPC2 Imaging No F439W /tmp/OPVisit26694.xml These observations take place with the same setup and filters as Visit 1, but occur 4-8 months later when the supernova is fainter, hence can be longer exposure times. (Tic-Visit :proposal-id 11171 :visit-id "01" :proposal-version -1 :trans-version "20070325" :date "08-May-2007 16:01:28.0" :trans-errors '(:WARNINGS 3 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 537792 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11171 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11171 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2820 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3144 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11171 :visit-id "01" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2820 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3144 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11171 :visit-id "01" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2820 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3144 :pcs-gap 0 ) true 3 3