17144( 5) - 05-Oct-2022 13:47:15 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17144 Version: 5 Check-in Time: 05-Oct-2022 13:47:15 STScI Edit Number: 0 Title Confirming the Formation of Black Holes ------------------------------------------------------------------------------------ Type Cycle GO 30 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Chris S. Kochanek The Ohio State University Y CoI: Jack Neustadt The Ohio State University N CoI: Dr. Krzysztof Z. Stanek The Ohio State University N ------------------------------------------------------------------------------------ Abstract 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. ------------------------------------------------------------------------------------ Observations Description ------------------------ 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. ------------------------------------------------------------------------------------ 17144( 5) - 05-Oct-2022 13:47:15 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6946-BH1 EXT-STAR, UNDESIGNATED RA=20H35M27.5600S, J2000 V = 25 DEC=+60D08'8.29" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 3 M101-OC1 EXT-STAR, UNDESIGNATED RA=14H03M17.2400S, J2000 V = 25 DEC=+54D22'7.60" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 17144( 5) - 05-Oct-2022 13:47:15 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.605 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 41.788 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.135 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 17144( 5) - 05-Oct-2022 13:47:15 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6946-BH1 WFC3/IR MULTIAC IR F110W NSAMP=14, SAMP-SEQ=STEP50 1 DEF PATTERN 1 1-2 CUM (1347.702 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6946-BH1 WFC3/IR MULTIAC IR F160W NSAMP=14, SAMP-SEQ=STEP50 1 DEF CUM (1347.702 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC6946-BH1 1 WFC3/IR MULTIAC IR F110W 1 none none none 1 N/A CUM NGC6946-BH1 1 WFC3/IR MULTIAC IR F110W 2 none none none 1 N/A CUM NGC6946-BH1 1 WFC3/IR MULTIAC IR F110W 3 none none none 1 N/A CUM NGC6946-BH1 2 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A CUM NGC6946-BH1 2 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A CUM NGC6946-BH1 2 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A CUM 17144( 5) - 05-Oct-2022 13:47:15 - [ 5] Visit: 02 Visit Requirements: ORIENT 210D TO 270 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 M101-OC1 WFC3/IR MULTIAC IR F160W NSAMP=14, SAMP-SEQ=STEP50 1 DEF POS TARG -35, -45; CUM (1347.702 PATTERN 1 1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 M101-OC1 WFC3/UVI ACCUM UVIS2-C51 F814W 1 350 S PATTERN 2 2 S 2C-CTE see below (1071 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ M101-OC1 1 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A CUM M101-OC1 1 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A CUM M101-OC1 1 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A CUM M101-OC1 2 WFC3/UVI ACCUM UVIS2-C5 F814W 1 none none none 1 357.0 S S 12C-CTE M101-OC1 2 WFC3/UVI ACCUM UVIS2-C5 F814W 2 none none none 1 357.0 S S 12C-CTE M101-OC1 2 WFC3/UVI ACCUM UVIS2-C5 F814W 3 none none none 1 357.0 S S 12C-CTE 17144( 5) - 05-Oct-2022 13:47:15 - [ 6] Summary Form for Proposal 17144 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, UVIS2-C512C-CTE ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=14, SAMP-SEQ=STEP50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 210D TO 270 D, PATTERN 1 1, PATTERN 1 1-2, PATTERN 2 2, POS TARG -35, -45 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W, F160W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names M101-OC1, NGC6946-BH1 ------------------------------------------------------------------------------------------------------------------------------------