0 Assigned ID: 3044 ----- Attempting Submission 1 (Thu Mar 24 19:32:56 GMT 2022) ----- HST Phase I Proposal 3044 successfully submitted. Receipt: # 3044-1 FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser OK, hopefully done correctly -- looks OK on aladdin for all orients from 210 to 270 pos targ on WFC3/IR moving detector away from the center of M101 and off the bright star north of the center, CTE pointing for WFC3/UVIS 1805554021 ----- Attempting Submission 1 (Tue Jul 05 11:31:41 GMT 2022) ----- HST Phase II Proposal 17144 successfully submitted. Receipt: # 17144-1 ----- Attempting Submission 2 (Tue Jul 05 14:20:24 GMT 2022) ----- HST Phase II Proposal 17144 successfully submitted. Receipt: # 17144-2 ----- Attempting Submission 3 (Wed Sep 28 14:20:36 GMT 2022) ----- HST Phase II Proposal 17144 successfully submitted. Receipt: # 17144-3 ----- Attempting Submission 4 (Mon Oct 03 13:30:18 GMT 2022) ----- HST Phase II Proposal 17144 successfully submitted. Receipt: # 17144-4 ----- Attempting Submission 5 (Wed Oct 05 13:14:46 GMT 2022) ----- observations are on the disk of M101 -- background is much higher than used in the estimate Confirming the Formation of Black Holes There are good observational and theoretical reasons to believe that 10-30% of the core-collapses of massive stars lead to the formation of black holes without a supernova explosion. A survey using the Large Binocular Telescope has identified one good candidate in NGC6946 and new candidate in M101. In N6946, a roughly 300,000 Lsun star vanished in the optical to leave a fading, few 1000 Lsun near-IR (HST F110W/F160W in 2015/2017) source. It is very difficult to reconcile the evolution with a dust enshrouded, but surviving, star. A new epoch of HST near-IR observations to confirm the continued fading will greatly strengthen this argument. The new candidate needs to be characterized to establish a baseline from which to evaluate its future evolution and status. Because of the low fluxes and crowding, good photometry can no longer be obtained from the ground. The goal is WF3/IR F160W and F110W observasions of one target and WF3/IR/F160W and WF3/UVIS/F814W observations of the other. Three dither positions will be used for each observation to control CRs and hot pixels. Experiments to try to get 4 UVIS images for better CR control were not successful due to buffer dumps. The multiaccum read was chosen to leave as close to no left over time as possible. The APT is warning about low background counts for CTE, but the image is on top of the nearby galaxy M101, so the background is much higher than for an extragalactic field (particularly given the filter) Other than scheduling, these observations should not be impacted by the loss of a gyroscope. From the visit planner results, it appears, however, that these observations have a lot of observing windows. This is the team which discovered these sources. We have analyzed and published HST observations of NGC~6946-BH1 that are essentially identical to those proposed here in Adams et al. (2017, MNRAS, 468, 4968) and Basinger et al. (2021, MNRAS, 508, 1156). The PI (Kochanek) has extensive, long term experience with HST observations and analysis (25 successful HST programs as PI). Stellar Physics and Stellar Types 6 false false false false false false false SUPPORTED EXT-STAR UNDESIGNATED NO J2000 J2000 EXT-STAR UNDESIGNATED NO J2000 J2000 WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F814W WFC3/IR Imaging No No F160W POS-TARG DITHER 0.605 LINE false false 3 41.788 WFC3-IR-DITHER-LINE-3PT 1 false POS-TARG DITHER 0.135 LINE false false 3 46.84 WFC3-UVIS-DITHER-LINE-3PT 2 false The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. /tmp/OPVisit11024464406449329342.xml (Tic-Visit :proposal-id 17144 :visit-id "01" :proposal-version -1 :trans-version "20220630" :date "05-Oct-2022 09:14:02.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1566800 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17144 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17144 :visit-id "01" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2953 :al-overhead-at-end 0 :internal-dur-at-end 500 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3411 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. /tmp/OPVisit14756215728333039309.xml (Tic-Visit :proposal-id 17144 :visit-id "02" :proposal-version -1 :trans-version "20220630" :date "05-Oct-2022 09:10:53.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1649648 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17144 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17144 :visit-id "02" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2949 :al-overhead-at-end 116 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3333 :pcs-gap 0 ) true 1 0