16076( 4) - 16-Apr-2020 22:11:35 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16076 Version: 4 Check-in Time: 16-Apr-2020 22:11:35 STScI Edit Number: 1 Title UV spectroscopy and imaging of the transient Swift J221951-484240 discovered in the follow-up of GW S190930t. ------------------------------------------------------------------------------------ Type Cycle GO 27 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Samantha Oates University of Birmingham Y CoI: Dr. N.P.M Paul Kuin Mullard Space Science Laboratory Y CoI: Dr. Stephen Bradley Cenko NASA Goddard Space Flight Center N CoI: Dr. Matt Nicholl University of Birmingham N CoI: Dr. David Buckley South African Astronomical Observatory N ------------------------------------------------------------------------------------ Abstract Swift/UVOT detected J221951-484240 on the 30th September 2019 as part of the search for an electromagnetic counterpart to the LIGO/VIRGO Gravitational Wave (GW) trigger S190930t; after the cycle 27 proposal deadline. Compared to archival UV images, J221951-484240 is brighter by over 3 magntidues. The nature of this blue-slowly evolving source remains unclear following Swift and ground-based follow-up. It is possible this transient is associated with S190930t or alternatively it may be a new class of UV-bright transient. HST UV data is the only means to constrain the distance to the source and its true nature. Determining this now will allow us to plan additional observations using Swift, HST and other resources to follow its evolution. Observations in the present cycle would also facilitate rapid publication, which is of particular importance as this source was identified during follow-up of a GW alert. Only HST has the UV spectroscopic capability to obtain the key data needed to identify the nature of this 19th magnitude u-band transient before it fades away. Owing to the unique nature of this source, these observations will lead to a timely and high-impact publication whether or not it is connected to the GW emission. ------------------------------------------------------------------------------------ Observations Description ------------------------ UV spectroscopy and imaging of the transient Swift J221951-484240 with COS and ACS ------------------------------------------------------------------------------------ 16076( 4) - 16-Apr-2020 22:11:35 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SWIFTJ221951 UNIDENTIFIED, INFRARED RA=22H19M51.8110S +/- 0.13", J2000 V = 19.6 +/- 0.5 -484240 EMITTER, OPTICAL DEC=-48D42'40.72" +/- 0.16" EMITTER, ULTRAVIOLET EMITTER, UNDESIGNATED Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 2 SWIFTJ221951 UNIDENTIFIED, BLANK RA-OFF=-0.99S, DEC-OFF=-0.233", J2000 V = 19.6 +/- 0.5 -484240-SAFE FIELD FROM 1 -TARGET Extended: NO Comments: This target is a blank piece of sky which is the bright object safe pointing and is 9.839 arcseconds away at a PA of 271.4 degrees U3. ------------------------------------------------------------------------------------------------------------------------------------ 16076( 4) - 16-Apr-2020 22:11:35 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.262 Line_Spacing 0.192 Coordinate_Frame POS-TARG Pattern_Orient 18.39 Angle_Between_Sides 68.14 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16076( 4) - 16-Apr-2020 22:11:35 - [ 4] Visit: 02 (ACS-WFC_image) 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 SWIFTJ22195 ACS/WFC ACCUM WFC1-CTE F475W GAIN=2.0 1 579 S PATTERN 1 1 1-484240 see below (2256 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 | ------------------------------------------------------------------------------------------------------------------------------------ SWIFTJ221951-484240 1 ACS/WFC ACCUM WFC1-CTE F475W 1 none none none 1 564.0 S SWIFTJ221951-484240 1 ACS/WFC ACCUM WFC1-CTE F475W 2 none none none 1 564.0 S SWIFTJ221951-484240 1 ACS/WFC ACCUM WFC1-CTE F475W 3 none none none 1 564.0 S SWIFTJ221951-484240 1 ACS/WFC ACCUM WFC1-CTE F475W 4 none none none 1 564.0 S 16076( 4) - 16-Apr-2020 22:11:35 - [ 5] Visit: 03 (COS_spectrum) Visit Requirements: ORIENT 105D TO 350 D; AFTER 04 BY 3 D TO 10 D; BEFORE 30-JUN-2020:00:00:00 On Hold Comments: Additional Comments: This visit should be scheduled in the evening local time. Flags need to be cleared during the workday. 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 SWIFTJ22195 COS/FUV ACQ/PEA PSA G130M 1291 NUM-POS=3, STEP-SIZE=1.3, 1 300 S (300 USE OFFSET V03SAF 1-484240 KXD CENTER=DEF, SEGMENT=BOTH, S) LIFETIME-POS=LP4 ------------------------------------------------------------------------------------------------------------------------------------ 2 SWIFTJ22195 COS/FUV ACQ/PEA PSA G130M 1291 STEP-SIZE=1.3, NUM-POS=3., 1 300 S (300 USE OFFSET V03SAF 1-484240 KD CENTER=DEF, SEGMENT=BOTH, S) LIFETIME-POS=LP4 ------------------------------------------------------------------------------------------------------------------------------------ 3 SWIFTJ22195 COS/FUV TIME-TA PSA G140L 1280 BUFFER-TIME=16862, FP-POS=ALL, 1 500 S USE OFFSET V03SAF 1-484240 G SEGMENT=BOTH see below (2275 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SWIFTJ22195 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=8544, FP-POS=ALL, 1 500 S USE OFFSET V03SAF 1-484240 G SEGMENT=A see below (3265 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 | ------------------------------------------------------------------------------------------------------------------------------------ SWIFTJ221951-484240 1 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A KXD SWIFTJ221951-484240 2 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A KD SWIFTJ221951-484240 3 COS/FUV TIME-TA PSA G140L 1280 none none none 1 1 607.0 S G SWIFTJ221951-484240 3 COS/FUV TIME-TA PSA G140L 1280 none none none 2 2 556.0 S G SWIFTJ221951-484240 3 COS/FUV TIME-TA PSA G140L 1280 none none none 3 2 556.0 S G SWIFTJ221951-484240 3 COS/FUV TIME-TA PSA G140L 1280 none none none 4 2 556.0 S G SWIFTJ221951-484240 4 COS/FUV TIME-TA PSA G140L 1105 none none none 1 2 556.0 S G SWIFTJ221951-484240 4 COS/FUV TIME-TA PSA G140L 1105 none none none 2 3 903.0 S G SWIFTJ221951-484240 4 COS/FUV TIME-TA PSA G140L 1105 none none none 3 3 903.0 S G 16076( 4) - 16-Apr-2020 22:11:35 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SWIFTJ221951-484240 4 COS/FUV TIME-TA PSA G140L 1105 none none none 4 3 903.0 S G 16076( 4) - 16-Apr-2020 22:11:35 - [ 7] Visit: 04 (S/C VISIT) Visit Requirements: ORIENT 105D TO 350 D On Hold Comments: Additional Comments: This visit allocates and sets up the safe position offset slot for visit 03 which will use that slot. This S/C visit should go earlier in the week while visit 03 will be at least 3 days later. 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 SWIFTJ22195 S/C DATA V1 1 5 S (5 S) POS TARG 229.13280000, 1-484240 -241.05750000; SAVE OFFSET V03SAF; SPEC COM INSTR ECSLOTSET; QESIPARM ANGLE 271.4; QESIPARM DIST 9.839 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SWIFTJ221951-484240 1 S/C DATA V1 none none none none 1 N/A 16076( 4) - 16-Apr-2020 22:11:35 - [ 8] Visit: 05 (SCIENCETARGET-BOP-ONLY) Visit Requirements: ORIENT 105D TO 350 D; BEFORE 30-JUN-2020:00:00:00 On Hold Comments: Additional Comments: This visit is for BOP checking the safe target only and should not execute onboard HST. 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 SWIFTJ22195 COS/FUV ACQ/PEA PSA G130M 1291 NUM-POS=3, STEP-SIZE=1.3, 1 300 S (300 1-484240-SA KXD CENTER=DEF, SEGMENT=BOTH, S) FE-TARGET LIFETIME-POS=LP4 ------------------------------------------------------------------------------------------------------------------------------------ 2 SWIFTJ22195 COS/FUV ACQ/PEA PSA G130M 1291 STEP-SIZE=1.3, NUM-POS=3., 1 300 S (300 1-484240-SA KD CENTER=DEF, SEGMENT=BOTH, S) FE-TARGET LIFETIME-POS=LP4 ------------------------------------------------------------------------------------------------------------------------------------ 3 SWIFTJ22195 COS/FUV TIME-TA PSA G140L 1280 BUFFER-TIME=16862, FP-POS=ALL, 1 500 S 1-484240-SA G SEGMENT=BOTH see below FE-TARGET (2275 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SWIFTJ22195 COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=8544, FP-POS=ALL, 1 500 S 1-484240-SA G SEGMENT=A see below FE-TARGET (3265 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 | ------------------------------------------------------------------------------------------------------------------------------------ SWIFTJ221951-484240 1 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A -SAFE-TARGET KXD SWIFTJ221951-484240 2 COS/FUV ACQ/PEA PSA G130M 1291 none none none none 1 N/A -SAFE-TARGET KD SWIFTJ221951-484240 3 COS/FUV TIME-TA PSA G140L 1280 none none none 1 1 607.0 S -SAFE-TARGET G SWIFTJ221951-484240 3 COS/FUV TIME-TA PSA G140L 1280 none none none 2 2 556.0 S -SAFE-TARGET G SWIFTJ221951-484240 3 COS/FUV TIME-TA PSA G140L 1280 none none none 3 2 556.0 S -SAFE-TARGET G SWIFTJ221951-484240 3 COS/FUV TIME-TA PSA G140L 1280 none none none 4 2 556.0 S -SAFE-TARGET G SWIFTJ221951-484240 4 COS/FUV TIME-TA PSA G140L 1105 none none none 1 2 556.0 S -SAFE-TARGET G SWIFTJ221951-484240 4 COS/FUV TIME-TA PSA G140L 1105 none none none 2 3 903.0 S -SAFE-TARGET G SWIFTJ221951-484240 4 COS/FUV TIME-TA PSA G140L 1105 none none none 3 3 903.0 S -SAFE-TARGET G SWIFTJ221951-484240 4 COS/FUV TIME-TA PSA G140L 1105 none none none 4 3 903.0 S -SAFE-TARGET G 16076( 4) - 16-Apr-2020 22:11:35 - [ 9] Summary Form for Proposal 16076 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA, V1, WFC1-CTE ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, COS/FUV, S/C ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ/PEAKD, ACQ/PEAKXD, DATA, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=16862, BUFFER-TIME=8544, CENTER=DEF, FP-POS=ALL, GAIN=2.0, LIFETIME-POS=LP4, NUM-POS=3, NUM-POS=3., SEGMENT=A, SEGMENT=BOTH, STEP-SIZE=1.3 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 04 BY 3 D TO 10 D, BEFORE 30-JUN-2020:00:00:00, ORIENT 105D TO 350 D, PATTERN 1 1, POS TARG 229.13280000, -241.05750000, QESIPARM ANGLE 271.4, QESIPARM DIST 9.839, SAVE OFFSET V03SAF, SPEC COM INSTR ECSLOTSET, USE OFFSET V03SAF ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F475W, G130M, G140L ------------------------------------------------------------------------------------------------------------------------------------ Target Names SWIFTJ221951-484240, SWIFTJ221951-484240-SAFE-TARGET ------------------------------------------------------------------------------------------------------------------------------------