17415( 7) - 15-Aug-2024 19:46:52 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17415 Version: 7 Check-in Time: 15-Aug-2024 19:46:52 STScI Edit Number: 4 Title SN 2019yvr: A Hydrogen-poor Supernova with Late-Time Circumstellar Interaction and a Progenitor Candidate ------------------------------------------------------------------------------------ Type Cycle GO 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Charles Kilpatrick Northwestern University Y CoI: Dr. Katie Auchettl University of Melbourne N CoI: Maria Drout University of Toronto N CoI: Prof. Ashley Villar Harvard University N CoI: Dr. Samaporn Tinyanont National Astronomical Research Institute N of Thailand ------------------------------------------------------------------------------------ Abstract There is now significant evidence that at least 10% of massive stars undergo substantial and impulsive mass loss within a few years of core-collapse. In particular, observations of interacting supernovae suggest that their progenitors undergo extreme episodes of mass-loss shortly before core collapse, creating a dense shell of circumstellar material (CSM). While most of our understanding of this link has come predominantly from hydrogen-rich supernovae, there is a growing population of SN initially classified as hydrogen free but with evidence of CSM interaction at later times. Here we propose to take advantage of HST sensitivity and angular resolution to observe the nearby (d=14.4 Mpc) Type Ib SN2019yvr and constrain the disappearance of its progenitor star and ongoing circumstellar interaction. SN2019yvr is only the second stripped envelope SN with a candidate progenitor detection in pre-explosion HST images, and 150 days post-explosion it began to shown signs of SN2014C-like interaction with a hydrogen-rich medium. We request new imaging in F438W and F555W to confirm the disappearance of its pre-explosion counterpart and determine whether it is interacting with CSM at large separations from the progenitor system, implying its progenitor system was losing mass thousands of years before core collapse. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to observe the site of the Type Ib supernova (SN Ib) 2019yvr with WFC3. This site was previously observed in 2017 with WFC3/UVIS F438W and F555W, which revealed the a point source consistent with being the supernova's counterpart. Our program will observe this same source more than 4 years after the explosion and determine whether it has faded or disappeared, consistent with predictions that it was the progenitor star of 2019yvr and exploded in 2019. To maximize time on-source within each orbit, we split our observations into two orbits of F438W and two of F555W, both using a 3-point line pattern to guarantee a high S/N detection of any potential counterpart as well as nearby sources that will aid in alignment and PSF reconstruction near the site of SN2019yvr. Combined with the requested FLASH in each exposure (FLASH=12 for 17415( 7) - 15-Aug-2024 19:46:52 - [ 2] F438W and no FLASH for F555W), this will also minimize the effects of CTE while maximizing the field observed around the host galaxy NGC4666. ------------------------------------------------------------------------------------ 17415( 7) - 15-Aug-2024 19:46:52 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2022CRV STAR, SUPERNOVA, RA=09H54M25.9100S, J2000 V = 24 SUPERNOVA TYPE IB DEC=-25D42'11.16" Reference Frame: Other: SIMBAD Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 17415( 7) - 15-Aug-2024 19:46:52 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 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 ------------------------------------------------------------------------------------------------------------------------------------ 17415( 7) - 15-Aug-2024 19:46:52 - [ 5] Visit: 02 (SN2022crv - 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 SN2022CRV WFC3/UVI ACCUM UVIS2 F438W FLASH=12 1 800 S PATTERN 1 1 S see below (2310 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2022CRV WFC3/UVI ACCUM UVIS2 F438W FLASH=12 1 800 S PATTERN 1 2 S see below (2361 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2022CRV WFC3/UVI ACCUM UVIS2 F606W 1 800 S PATTERN 1 3 S see below (2376 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2022CRV WFC3/UVI ACCUM UVIS2 F606W 1 800 S PATTERN 1 4 S see below (2376 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2022CRV 1 WFC3/UVI ACCUM UVIS2 F438W 1 none none none 1 770.0 S S SN2022CRV 1 WFC3/UVI ACCUM UVIS2 F438W 2 none none none 1 770.0 S S SN2022CRV 1 WFC3/UVI ACCUM UVIS2 F438W 3 none none none 1 770.0 S S SN2022CRV 2 WFC3/UVI ACCUM UVIS2 F438W 1 none none none 2 787.0 S S SN2022CRV 2 WFC3/UVI ACCUM UVIS2 F438W 2 none none none 2 787.0 S S SN2022CRV 2 WFC3/UVI ACCUM UVIS2 F438W 3 none none none 2 787.0 S S SN2022CRV 3 WFC3/UVI ACCUM UVIS2 F606W 1 none none none 3 792.0 S S SN2022CRV 3 WFC3/UVI ACCUM UVIS2 F606W 2 none none none 3 792.0 S S SN2022CRV 3 WFC3/UVI ACCUM UVIS2 F606W 3 none none none 3 792.0 S S SN2022CRV 4 WFC3/UVI ACCUM UVIS2 F606W 1 none none none 4 792.0 S S 17415( 7) - 15-Aug-2024 19:46:52 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2022CRV 4 WFC3/UVI ACCUM UVIS2 F606W 2 none none none 4 792.0 S S SN2022CRV 4 WFC3/UVI ACCUM UVIS2 F606W 3 none none none 4 792.0 S S 17415( 7) - 15-Aug-2024 19:46:52 - [ 7] Summary Form for Proposal 17415 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=12 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1, PATTERN 1 2, PATTERN 1 3, PATTERN 1 4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F438W, F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN2022CRV ------------------------------------------------------------------------------------------------------------------------------------