15311( 2) - 18-Jul-2017 19:55:11 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15311 Version: 2 Check-in Time: 18-Jul-2017 19:55:11 STScI Edit Number: 0 Title Confirming the Formation of a Black Hole ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Chris S. Kochanek The Ohio State University Y CoI: Dr. Krzysztof Z. Stanek The Ohio State University N CoI: Dr. Scott Adams California Institute of Technology N CoI: Mr. Samson Johnson 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. We have been carrying out the first observational search for such failed supernovae using the Large Binocular Telescope. From seven years of LBT survey data we have one good candidate, NGC6946-BH1. HST observations in 2015 found a possible near-IR counterpart to the candidate that is significantly less luminous than the progenitor. If the source is related to BH1, this could be either emission from late time accretion luminosity or obscuration of a surviving star by an expanding shell of dust too cool to be detected in our warm SST observations. New HST WFC3/IR observations of the source should find that the source is either fainter (late-time accretion) or brighter (obscured by an expanding shell). This is critical information to inform proposals for JWST observations to search for colder dust. ------------------------------------------------------------------------------------ Observations Description ------------------------ The goal is to obtain two IR (F110W and F160W) WFC3 images of a candidate failed supernova, where a massive star has undergone core collapse to form a black hole without an external supernova explosion. The filters and exposure times are chosen to match our previous observations. ------------------------------------------------------------------------------------ 15311( 2) - 18-Jul-2017 19:55:11 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6946-BH1 STAR, ACCRETION DISK RA=20H35M27.5600S, J2000 V = 28.4 F110W 23.8 F160W 22.4 in cycle DEC=+60D08'8.29" 23 Reference Frame: Other: J2000 ------------------------------------------------------------------------------------------------------------------------------------ 15311( 2) - 18-Jul-2017 19:55:11 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 15311( 2) - 18-Jul-2017 19:55:11 - [ 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 F160W NSAMP=11, SAMP-SEQ=STEP100 1 DEF PATTERN 1 1-2 CUM (1497.696 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6946-BH1 WFC3/IR MULTIAC IR F110W 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 F160W 1 none none none 1 N/A CUM NGC6946-BH1 1 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A CUM NGC6946-BH1 1 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A CUM NGC6946-BH1 2 WFC3/IR MULTIAC IR F110W 1 none none none 1 N/A CUM NGC6946-BH1 2 WFC3/IR MULTIAC IR F110W 2 none none none 1 N/A CUM NGC6946-BH1 2 WFC3/IR MULTIAC IR F110W 3 none none none 1 N/A CUM 15311( 2) - 18-Jul-2017 19:55:11 - [ 5] Summary Form for Proposal 15311 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=11, NSAMP=14, SAMP-SEQ=STEP100, SAMP-SEQ=STEP50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1-2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W, F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC6946-BH1 ------------------------------------------------------------------------------------------------------------------------------------