corrected typo -747345285 Assigned ID: 1249 ----- Attempting Submission 1 (Thu Feb 28 18:18:08 GMT 2013) ----- HST Phase I Proposal 1249 (impostor.apt) successfully submitted. ----- Attempting Submission 2 (Thu Feb 28 22:17:42 GMT 2013) ----- HST Phase I Proposal 1249 (impostor.apt) successfully submitted. 0 ----- Attempting Submission 1 (Tue Jun 11 12:59:22 GMT 2013) ----- Unmasking the Supernova Impostors We propose measuring the optical/near-IR/mid-IR spectral energy distributions of the three nearby ``supernova impostors'' SN1954J, SN1961V and SN1997bs. All three have candidate surviving stars which, in order to explain their faintness, are believed to be shrouded by dusty shells formed during the eruption. If this hypothesis is correct, we will be able to estimate the mass lost in the eruption, a key step towards understanding the physics of eruptions and their role in the evolution of massive stars. In the case of SN~1961V, however, the most likely outcome is to conclusively show that the standard hypothesis is wrong and that the transient was a true supernova. This outcome is less likely for the other two targets, but it would be revolutionary and is not disallowed by the existing fragmentary data. The goal is to obtain two optical (either F475W or F555W plus F814W) and two IR (F110W and F160W) WFC3 images of three "supernova impostors" in order to try to measure the SED of any surviving star on a long enough wavelength baseline to simultaneously estimate the stellar temperature, luminosity and extinction by circumstellar dust. Spitzer observations will be used to measure emission by the circumstellar dust. The blue WFC3/UVIS filter is picked to best match the available archival filters to optimize the ability to detect changes. For UVIS, observing filter 1 at all dither points followed by filter 2 at all dither points produced slightly higher total integration times than interleaving the filters. There are 50 unused seconds in visit 03 WFC3/IR for which there was no efficient filler given the quantization of the WFC3/IR observing modes. However, mixing the optical/IR filters in each orbit (where auto-adjust on the optical would fill the time) seems to consistently produce slightly less total integration time. While no constraints were requested, the archival value of the data would be maximized by shifting between the UVIS1 and UVIS2 pointing centers to put more of the chip real estate on the host galaxy of these sources given the orientation at the time of the observations. This would have no effect on the primary science. HOT STARS Default false false 0.8 false false false SUPPORTED EXT-STAR LUMINOUS BLUE VARIABLE SUPERNOVA This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 EXT-STAR LUMINOUS BLUE VARIABLE SUPERNOVA This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 EXT-STAR LUMINOUS BLUE VARIABLE SUPERNOVA This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W ACS/WFC Imaging No No F435W ACS/WFC Imaging No No F814W ACS/WFC Imaging No No F435W POS-TARG DITHER 0.135 LINE false false 3 46.84 WFC3-UVIS-DITHER-LINE-3PT 1 false POS-TARG DITHER 0.636 LINE false false 2 41.788 WFC3-IR-DITHER-LINE 2 false /tmp/OPVisit4241708394576793989.xml The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13477 :visit-id "01" :proposal-version -1 :trans-version "20130502" :date "11-Jun-2013 08:23:38.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2985936 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13477 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13477 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3248 :al-overhead-at-end 116 :internal-dur-at-end 31 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3582 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13477 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3322 :al-overhead-at-end 0 :internal-dur-at-end 595 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3582 :pcs-gap 0 ) true 2 0 /tmp/OPVisit1256564955055969396.xml The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13477 :visit-id "02" :proposal-version -1 :trans-version "20130502" :date "11-Jun-2013 08:23:42.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2985936 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13477 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13477 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2954 :al-overhead-at-end 116 :internal-dur-at-end 31 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3287 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13477 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3022 :al-overhead-at-end 0 :internal-dur-at-end 633 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3287 :pcs-gap 0 ) true 2 0 /tmp/OPVisit1013148271194941146.xml The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13477 :visit-id "03" :proposal-version -1 :trans-version "20130502" :date "11-Jun-2013 08:32:36.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2707392 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13477 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13477 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2903 :al-overhead-at-end 116 :internal-dur-at-end 31 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3239 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13477 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2962 :al-overhead-at-end 0 :internal-dur-at-end 576 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3239 :pcs-gap 0 ) true 2 0