17889( 4) - 29-Nov-2024 18:16:06 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17889 Version: 4 Check-in Time: 29-Nov-2024 18:16:06 STScI Edit Number: 0 Title Tracking the Emergence of an Accretion Disk in an LFBOT ------------------------------------------------------------------------------------ Type Cycle GO/DD 32 ------------------------------------------------------------------------------------ Investigators Contact? PI: Anna Yen Qin Ho Cornell University Y CoI: Mr. Wynn Vicente Jacobson-Galan California Institute of Technology N CoI: Dr. Daniel Perley Liverpool John Moores University N CoI: Dr. Lin Yan California Institute of Technology N CoI: Igor Andreoni NASA Goddard Space Flight Center N CoI: Dr. Ping Chen Weizmann Institute of Science N CoI: Genevieve Schroeder Northwestern University N CoI: Gokul Prem Srinivasaragavan University of Maryland N CoI: Dr. Yu-jing Qin California Institute of Technology N CoI: Jada Vail Cornell University N CoI: Harlan Phillips University of California - Berkeley N CoI: Marquice Sanchez-Fleming Cornell University N CoI: Jacob Wise Liverpool John Moores University N CoI: Dr. Jesper Sollerman Stockholm University N CoI: Ola Bochenek Liverpool John Moores University N CoI: Jamie Wright Liverpool John Moores University N ------------------------------------------------------------------------------------ Abstract In recent years, high-cadence wide-field surveys have revealed unexpected new classes of phenomena, including luminous fast blue optical transients (LFBOTs) such as AT2018cow. The progenitor of LFBOTs is unknown, but they likely involve the formation of an accretion disk that transitions from super-Eddington to ~sub-Eddington accretion rates on a timescale of ~100 days. One of the major clues was HST's detection of luminous UV emission at the position of AT2018cow 2-4 after the original transient. Unfortunately, in AT2018cow the lack of observations between 2 months post-transient and 2 years post-transient meant that the emergence of this luminous UV source was not observed. In this proposal we request HST UV observations of AT2024wpp, the first LFBOT that is both nearby enough and discovered early enough to obtain a detailed UV light curve on timescales spanning days to years. The goal of our DD request is to monitor the UV light curve of AT2024wpp from 2 months to 2 years post-outburs. Multi-frequency HST observations will teach us both about the progenitor of LFBOTs and about the accretion physics operating in these systems; observational constraints on disk physics in this phase would have broad astrophysical applications. In addition, detecting the transient with HST will enable precise astrometry for comparison to a later host-galaxy image, another important clue to the progenitor system. ------------------------------------------------------------------------------------ Observations Description ------------------------ As per our Phase I proposal we request two non-disruptive ToO activations. The first will consist of 2 orbits, 4 filters total, and should take place in the 17889( 4) - 29-Nov-2024 18:16:06 - [ 2] window Dec 10-19 (but all 4 filters should be observed close together in time). The second is 4 orbits, 4 filters total, and should take place in the window June 18 - July 22 (but again, all 4 filters should be observed close together in time). ------------------------------------------------------------------------------------ 17889( 4) - 29-Nov-2024 18:16:06 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 AT2024WPP UNIDENTIFIED, ACCRETION RA=02H42M5.4833S, J2000 Z = V = 23 DISK, EJECTA, OPTICAL DEC=-16D57'23.07" 0.0868 EMITTER, RADIO EMITTER, X-RAY EMITTER Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 17889( 4) - 29-Nov-2024 18:16:06 - [ 4] 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 ------------------------------------------------------------------------------------------------------------------------------------ 17889( 4) - 29-Nov-2024 18:16:06 - [ 5] Visit: 01 (Epoch1) Visit Requirements: BETWEEN 10-DEC-2024:00:00:00 AND 20-DEC-2024:00:00:00; TOO RESPONSE TIME 21.0D 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 AT2024WPP WFC3/UVI ACCUM UVIS F225W FLASH=19 1 548 S PATTERN 1 1 S (1096 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2024WPP WFC3/UVI ACCUM UVIS F336W FLASH=19 1 548 S PATTERN 1 2 S (1096 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 AT2024WPP WFC3/UVI ACCUM UVIS F555W FLASH=6 1 553 S PATTERN 1 3 S see below (1098 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 AT2024WPP WFC3/UVI ACCUM UVIS F814W FLASH=6 1 550 S PATTERN 1 4 S see below (1098 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2024WPP 1 WFC3/UVI ACCUM UVIS F225W 1 none none none 1 N/A S AT2024WPP 1 WFC3/UVI ACCUM UVIS F225W 2 none none none 1 N/A S AT2024WPP 2 WFC3/UVI ACCUM UVIS F336W 1 none none none 1 N/A S AT2024WPP 2 WFC3/UVI ACCUM UVIS F336W 2 none none none 1 N/A S AT2024WPP 3 WFC3/UVI ACCUM UVIS F555W 1 none none none 2 549.0 S S AT2024WPP 3 WFC3/UVI ACCUM UVIS F555W 2 none none none 2 549.0 S S AT2024WPP 4 WFC3/UVI ACCUM UVIS F814W 1 none none none 2 549.0 S S AT2024WPP 4 WFC3/UVI ACCUM UVIS F814W 2 none none none 2 549.0 S S 17889( 4) - 29-Nov-2024 18:16:06 - [ 6] Visit: 02 (Epoch2) Visit Requirements: BETWEEN 18-JUN-2025 AND 23-JUL-2025; TOO RESPONSE TIME 211.0D 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 AT2024WPP WFC3/UVI ACCUM UVIS F225W FLASH=18 1 555 S PATTERN 2 1 S (2220 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2024WPP WFC3/UVI ACCUM UVIS F336W FLASH=18 1 550 S PATTERN 2 2 S (2200 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 AT2024WPP WFC3/UVI ACCUM UVIS F555W FLASH=5 1 554 S PATTERN 2 3 S (2216 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 AT2024WPP WFC3/UVI ACCUM UVIS F814W FLASH=7 1 557 S PATTERN 2 4 S see below (2216 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2024WPP 1 WFC3/UVI ACCUM UVIS F225W 1 none none none 1 N/A S AT2024WPP 1 WFC3/UVI ACCUM UVIS F225W 2 none none none 1 N/A S AT2024WPP 1 WFC3/UVI ACCUM UVIS F225W 3 none none none 1 N/A S AT2024WPP 1 WFC3/UVI ACCUM UVIS F225W 4 none none none 1 N/A S AT2024WPP 2 WFC3/UVI ACCUM UVIS F336W 1 none none none 2 N/A S AT2024WPP 2 WFC3/UVI ACCUM UVIS F336W 2 none none none 2 N/A S AT2024WPP 2 WFC3/UVI ACCUM UVIS F336W 3 none none none 2 N/A S AT2024WPP 2 WFC3/UVI ACCUM UVIS F336W 4 none none none 2 N/A S AT2024WPP 3 WFC3/UVI ACCUM UVIS F555W 1 none none none 3 N/A S AT2024WPP 3 WFC3/UVI ACCUM UVIS F555W 2 none none none 3 N/A S AT2024WPP 3 WFC3/UVI ACCUM UVIS F555W 3 none none none 3 N/A S 17889( 4) - 29-Nov-2024 18:16:06 - [ 7] 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2024WPP 3 WFC3/UVI ACCUM UVIS F555W 4 none none none 3 N/A S AT2024WPP 4 WFC3/UVI ACCUM UVIS F814W 1 none none none 4 554.0 S S AT2024WPP 4 WFC3/UVI ACCUM UVIS F814W 2 none none none 4 554.0 S S AT2024WPP 4 WFC3/UVI ACCUM UVIS F814W 3 none none none 4 554.0 S S AT2024WPP 4 WFC3/UVI ACCUM UVIS F814W 4 none none none 4 554.0 S S 17889( 4) - 29-Nov-2024 18:16:06 - [ 8] Summary Form for Proposal 17889 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=18, FLASH=19, FLASH=5, FLASH=6, FLASH=7 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 10-DEC-2024:00:00:00 AND 20-DEC-2024:00:00:00, BETWEEN 18-JUN-2025 AND 23-JUL-2025, PATTERN 1 1, PATTERN 1 2, PATTERN 1 3, PATTERN 1 4, PATTERN 2 1, PATTERN 2 2, PATTERN 2 3, PATTERN 2 4, TOO RESPONSE TIME 21.0D, TOO RESPONSE TIME 211.0D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F225W, F336W, F555W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names AT2024WPP ------------------------------------------------------------------------------------------------------------------------------------