16874( 2) - 01-Dec-2021 17:08:49 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16874 Version: 2 Check-in Time: 01-Dec-2021 17:08:49 STScI Edit Number: 0 Title The Progenitor System and Ongoing Circumstellar Interaction of SN 2021qvr ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Charles Kilpatrick Northwestern University Y CoI: Mr. Wynn Vicente Jacobson-Galan University of California - Berkeley N CoI: Dr. Samaporn Tinyanont University of California - Santa Cruz N ------------------------------------------------------------------------------------ Abstract Ultra-rapid or "flash" spectroscopy of young core-collapse supernovae enables the detection of narrow emission lines that arise from shock ionization of local circumstellar material (CSM). This CSM is a direct tracer of progenitor star surface abundance in the last years before explosion and mass-loss history. A completely independent method for establishing progenitor properties is through direct detection of a source in deep pre-explosion imaging. SN 2021qvr is an extremely rare type II-L supernova with both flash spectra and progenitor candidates in pre-explosion imaging. However, to fully leverage these data, we need high-resolution follow up imaging to isolate the progenitor candidate in pre-explosion HST frames. In addition, ultraviolet follow-up imaging would enable us to understand its late-time bolometric behavior and to constrain the CSM mass ejected decades before core collapse, establishing how the progenitor star evolved and what its mass-loss rate was in the final years before explosion. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will observe the site of supernova (SN) 2021qvr during Cycle 29 with the Wide Field Camera 3 UV/visible detecting CCD in F275W, F336W, and F555W. We expect the SN to be 24-26 mag in the UV bands at the time it is observed and around 20-22 mag in F555W. Our goal is to obtain deep imaging of SN2021qvr and the surrounding field in the two UV filters while maximizing the signal-to-noise. We will therefore use 1 orbit in F275W and 2/3 orbit in F336W. We expect to achieve S/N>10 on SN2021qvr in both frames given our setup and exposure times. The remaining 1/3 orbit in F555W is designed to overlap with pre-explosion UVIS imaging in the same filter in order to perform astrometric alignment between the two images. The technical goal is therefore to detect as many point sources as possible that overlap with the pre-explosion frames. We expect to observe sources down to F555W = 25.5 mag at S/N>10, which should result in hundreds of astrometric calibrators to achieve our goal of <=0.01 arcsec alignment precision. ------------------------------------------------------------------------------------ 16874( 2) - 01-Dec-2021 17:08:49 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2021QVR STAR, SUPERNOVA, RA=23H28M26.6500S, J2000 V = 25 SUPERNOVA TYPE II DEC=+22D25'12.00" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 16874( 2) - 01-Dec-2021 17:08:49 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.145 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16874( 2) - 01-Dec-2021 17:08:49 - [ 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 SN2021QVR WFC3/UVI ACCUM UVIS1-FIX F275W FLASH=15 1 600 S PATTERN 2 1 S see below (2352 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2021QVR WFC3/UVI ACCUM UVIS1-FIX F336W FLASH=18 1 800 S PATTERN 1 2 S see below (1560 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2021QVR WFC3/UVI ACCUM UVIS1-FIX F555W FLASH=10 1 400 S PATTERN 1 3 S see below (760 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2021QVR 1 WFC3/UVI ACCUM UVIS1-FI F275W 1 none none none 1 588.0 S S X SN2021QVR 1 WFC3/UVI ACCUM UVIS1-FI F275W 2 none none none 1 588.0 S S X SN2021QVR 1 WFC3/UVI ACCUM UVIS1-FI F275W 3 none none none 1 588.0 S S X SN2021QVR 1 WFC3/UVI ACCUM UVIS1-FI F275W 4 none none none 1 588.0 S S X SN2021QVR 2 WFC3/UVI ACCUM UVIS1-FI F336W 1 none none none 2 780.0 S S X SN2021QVR 2 WFC3/UVI ACCUM UVIS1-FI F336W 2 none none none 2 780.0 S S X SN2021QVR 3 WFC3/UVI ACCUM UVIS1-FI F555W 1 none none none 2 380.0 S S X SN2021QVR 3 WFC3/UVI ACCUM UVIS1-FI F555W 2 none none none 2 380.0 S S X 16874( 2) - 01-Dec-2021 17:08:49 - [ 5] Summary Form for Proposal 16874 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=10, FLASH=15, FLASH=18 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 2, PATTERN 1 3, PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F275W, F336W, F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN2021QVR ------------------------------------------------------------------------------------------------------------------------------------