17496( 9) - 20-Mar-2025 19:22:17 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17496 Version: 9 Check-in Time: 20-Mar-2025 19:22:17 STScI Edit Number: 6 Title Expanding shocks and the emergence of the compact object in Supernova 1987A ------------------------------------------------------------------------------------ Type Cycle GO 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Josefin Larsson Royal Institute of Technology Y CoI: Prof. Claes Fransson Stockholm University N CoI: Prof. Robert P. Kirshner Harvard University N CoI: Mr. Peter Challis Harvard University N CoI: Dr. Roger A. Chevalier The University of Virginia N CoI: Prof. Kevin France University of Colorado at Boulder N CoI: Prof. Kevin Heng Ludwig Maximilian Universitat of Munich N CoI: Dr. Stephen S. Lawrence Hofstra University N CoI: Prof. Peter Lundqvist Stockholm University N CoI: Dr. Seppo Mattila University of Turku N CoI: Dr. Bruno Leibundgut European Southern Observatory - Germany N CoI: Dr. Nicholas B. Suntzeff Texas A & M University N CoI: Dr. Jesper Sollerman Stockholm University N CoI: Dr. Mikako Matsuura Cardiff University N CoI: Dr. Sophie ROSU University of Geneva, Department of N Astronomy CoI: Dr. Jason Spyromilio European Southern Observatory - Germany N CoI: Dr. Tea Temim Princeton University N CoI: Dr. Alec S. Hirschauer Morgan State University N CoI: Dr. Patrick Kavanagh National University of Ireland, Maynooth N ------------------------------------------------------------------------------------ Abstract By a fortunate turn of events, SN 1987A, the brightest supernova (SN) since 1604, exploded just a few years before the launch of HST. This has allowed HST to monitor the evolution from the very beginning as the SN evolves into a remnant, proving astronomers with a unique laboratory for SN physics. The most recent observations show major changes in the interaction with the iconic triple-ring nebula of circumstellar material. The dense, inner ejecta are just starting to crash into the equatorial ring, while the shocks further out in the system are gradually revealing the mass-loss history of the progenitor star. Furthermore, JWST has recently detected the first clear electromagnetic signal from the compact object created in the explosion, though its properties are yet to be determined. We request imaging in narrow and broad filters over the next three cycles, as well as a COS spectrum in Cycle 31, to study the shock interaction and compact object. The observations will be used to determine the conditions in the shock region, the properties of the circumstellar medium, and constrain the main competing scenarios for the compact object. Annual observations are needed to track the rapid evolution of the shocks and the emerging emission from the compact object. Taken together, this will allow the properties of the progenitor and compact object to be connected for the first time. The HST observations are also indispensable for interpreting other multiwavelength observations of SN 1987A. ------------------------------------------------------------------------------------ 17496( 9) - 20-Mar-2025 19:22:17 - [ 2] Observations Description ------------------------ The requested observervations include 6 orbits with WFC3/UVIS and 11 orbits with COS. WFC3 Imaging: We request imaging in F625W, F502N, F657N and F763M in cycle 31. The first three filters are needed to measure the propagation of all the shock components and connect to the previous monitoring, while F763M will be used to search for signs of the compact object. To obtain a similar S/N as the previous observations, considering the fading of the system, we require one orbit each for F625W and F657N, and two orbits for F502N. The most interesting line from the compact object in the F763M filter is the [Ar III] 7753 line. Model predictions give a typical luminosity ~0.1* the [Ar II] 6.99 um luminosity, which results in a flux of 9 * 10^-17 erg cm^-2 s^-1. With a FWHM of 200 km s^-1, this results in a S/N ~14 in 6000 s. We therefore request two orbits with F763M to search for the compact object. Since 2003, all ACS and WFC3 imaging have used a fixed dither strategy to improve the spatial resolution, which will be repeated for consistency. COS spectrum: We will observe SN 1987A using central wavelength settings of the G130M (1291, 1318) and G160M (1600, 1611, 1623) gratings, which ensures continuous wavelength coverage at relatively constant S/N, and effectively performs a focal plane split to minimize fixed pattern noise. The 1318 setting for G130M is needed to provide continuous wavelength coverage across the full G130M spectral region and to compare with previous epochs of COS data. The limited spatial resolution of COS (about 1" in a 2.5" aperture) leaves some spatialspectral ambiguity in the deep spectral data. However, different emission components can be separated based on different line widths and Doppler shifts. While STIS would provide spatial information, its lower sensitivity makes it unsuitable for our objectives. We require a similar S/N as in the COS spectrum from 2017 (Fig. 7) to model the shocked emission from the ring and search for possible new lines from the compact object. Assuming that the UV flux from the ring has faded by 30% since 2017 (as in the optical), we require 3.5 orbits with G130M and 7 orbits with G160M. Combining these, and including extra time to account for the overheads introduced in Cycle 30 by the extra wavelength calibration at LP6, we require 11 orbits for the COS observations. We have run the Bright Object Tools and no bright object violations are detected. This, combined with the offset acquisition, makes the observations safe to execute. ------------------------------------------------------------------------------------ 17496( 9) - 20-Mar-2025 19:22:17 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN-1987A EXT-MEDIUM, SNR RA=05H35M28.0200S, J2000 V = 22 DEC=-69D16'11.07" Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. 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 ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-1987A-COS EXT-STAR, A0-A3 III-I, RA=05H35M30.5100S +/- 0.1", J2000 V = 16.071 B=15.915, U=15.029 -ACQ B3-B5 III-I DEC=-69D16'18.52" +/- 0.1" Reference Frame: ICRS Extended: NO Comments: V=16.071, B-V=-0.156, U-B=-0.886, V-R=-0.057, V-I=-0.109 B=15.915 U=15.029 COS.A351911, ACQ= MIRROR B + PSA Brightest pixel 18.753 Count rate entire detector 515.776 ives: Time = 11.8457 ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-1987A-COS EXT-MEDIUM, SNR RA-OFF=-2.5S, DEC-OFF=7.6", FROM J2000 V = 23.0 2 Reference Frame: ICRS Extended: YES Comments: This object was generated by the targetselector and retrieved from the NED database. ------------------------------------------------------------------------------------------------------------------------------------ 17496( 9) - 20-Mar-2025 19:22:17 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 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 ------------------------------------------------------------------------------------------------------------------------------------ 17496( 9) - 20-Mar-2025 19:22:17 - [ 5] Visit: 01 Visit Requirements: ORIENT 78D TO 82 D; ORIENT 168D TO 172 D; ORIENT 258D TO 262 D; ORIENT 348D TO 352 D; BETWEEN 10-MAY-2024:00:00:00 AND 15-OCT-2024:00:00:00; SEQ 01, 02 WITHIN 14 D On Hold Comments: Additional Comments: The orienation constraints are set to make sure that the diffraction spikes from "Star 3" (Fig. 1 of the proposal) do not overlap with the emission from the SN. 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 SN-1987A WFC3/UVI ACCUM UVIS2-C1K F502N CR-SPLIT=NO, FLASH=16 1 576 S PATTERN 1 1-3 S 1C-CTE (2304 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-1987A WFC3/UVI ACCUM UVIS2-C1K F502N CR-SPLIT=NO, FLASH=16 1 576 S S 1C-CTE (2304 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-1987A WFC3/UVI ACCUM UVIS2-C1K F657N CR-SPLIT=NO, FLASH=15 1 576 S S 1C-CTE (2304 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN-1987A 1 WFC3/UVI ACCUM UVIS2-C1 F502N 1 none none none 1 N/A S K1C-CTE SN-1987A 1 WFC3/UVI ACCUM UVIS2-C1 F502N 2 none none none 1 N/A S K1C-CTE SN-1987A 1 WFC3/UVI ACCUM UVIS2-C1 F502N 3 none none none 2 N/A S K1C-CTE SN-1987A 1 WFC3/UVI ACCUM UVIS2-C1 F502N 4 none none none 3 N/A S K1C-CTE SN-1987A 2 WFC3/UVI ACCUM UVIS2-C1 F502N 1 none none none 1 N/A S K1C-CTE SN-1987A 2 WFC3/UVI ACCUM UVIS2-C1 F502N 2 none none none 2 N/A S K1C-CTE SN-1987A 2 WFC3/UVI ACCUM UVIS2-C1 F502N 3 none none none 2 N/A S K1C-CTE SN-1987A 2 WFC3/UVI ACCUM UVIS2-C1 F502N 4 none none none 3 N/A S K1C-CTE SN-1987A 3 WFC3/UVI ACCUM UVIS2-C1 F657N 1 none none none 1 N/A S K1C-CTE SN-1987A 3 WFC3/UVI ACCUM UVIS2-C1 F657N 2 none none none 2 N/A S K1C-CTE SN-1987A 3 WFC3/UVI ACCUM UVIS2-C1 F657N 3 none none none 3 N/A S K1C-CTE SN-1987A 3 WFC3/UVI ACCUM UVIS2-C1 F657N 4 none none none 3 N/A S K1C-CTE 17496( 9) - 20-Mar-2025 19:22:17 - [ 6] Visit: 02 Visit Requirements: ORIENT 78D TO 82 D; ORIENT 168D TO 172 D; ORIENT 258D TO 262 D; ORIENT 348D TO 352 D; SEQ 01, 02 WITHIN 14 D On Hold Comments: Additional Comments: The orienation constraints are set to make sure that the diffraction spikes from "Star 3" (Fig. 1 of the proposal) do not overlap with the emission from the SN. 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 SN-1987A WFC3/UVI ACCUM UVIS2-C1K F625W CR-SPLIT=NO, FLASH=5 1 578 S PATTERN 1 1-3 S 1C-CTE (2312 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-1987A WFC3/UVI ACCUM UVIS2-C1K F763M CR-SPLIT=NO, FLASH=10 1 578 S S 1C-CTE (2312 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-1987A WFC3/UVI ACCUM UVIS2-C1K F763M CR-SPLIT=NO, FLASH=10 1 578 S S 1C-CTE (2312 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN-1987A 1 WFC3/UVI ACCUM UVIS2-C1 F625W 1 none none none 1 N/A S K1C-CTE SN-1987A 1 WFC3/UVI ACCUM UVIS2-C1 F625W 2 none none none 1 N/A S K1C-CTE SN-1987A 1 WFC3/UVI ACCUM UVIS2-C1 F625W 3 none none none 2 N/A S K1C-CTE SN-1987A 1 WFC3/UVI ACCUM UVIS2-C1 F625W 4 none none none 3 N/A S K1C-CTE SN-1987A 2 WFC3/UVI ACCUM UVIS2-C1 F763M 1 none none none 1 N/A S K1C-CTE SN-1987A 2 WFC3/UVI ACCUM UVIS2-C1 F763M 2 none none none 2 N/A S K1C-CTE SN-1987A 2 WFC3/UVI ACCUM UVIS2-C1 F763M 3 none none none 2 N/A S K1C-CTE SN-1987A 2 WFC3/UVI ACCUM UVIS2-C1 F763M 4 none none none 3 N/A S K1C-CTE SN-1987A 3 WFC3/UVI ACCUM UVIS2-C1 F763M 1 none none none 1 N/A S K1C-CTE SN-1987A 3 WFC3/UVI ACCUM UVIS2-C1 F763M 2 none none none 2 N/A S K1C-CTE SN-1987A 3 WFC3/UVI ACCUM UVIS2-C1 F763M 3 none none none 3 N/A S K1C-CTE SN-1987A 3 WFC3/UVI ACCUM UVIS2-C1 F763M 4 none none none 3 N/A S K1C-CTE 17496( 9) - 20-Mar-2025 19:22:17 - [ 7] Visit: 03 Visit Requirements: ORIENT 60.0D TO 90.0 D; SEQ 03, 04 WITHIN 10 D On Hold Comments: Additional Comments: ideal angle is 75. Note that an identical copy of these observations were carried out in Cycle 19. These data will allow us to inspect the relatively temporal variability of the lines and continuum. 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 SN-1987A-CO COS/NUV ACQ/IMA PSA MIRRORB 1 14 S (14 S-ACQ GE S) Comments: COS.A351911 Model ID = 98217 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.03 in magnitudes relative to Vega COS.A351916 Kurucz (B5V): Temp = 15400, I avereage the two.. 12 seconds with B3V, and 16 seconds with B5V ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-1987A-CO COS/NUV TIME-TA PSA MIRRORB BUFFER-TIME=490 1 600 S S G see below (411 S) Comments: star 3: V=15.60 B-V 0.46 U-B -0.89 V = 15.60 B=16.06 U=15.17 B3 star Exposure ID: COS.A331360 If the aperture falls on nearby star 3; COS.A331366 Brightest pixel 16.484 Count rate entire detector 491.586 Exposure time (seconds) = 600.0000 Model ID = 96513 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.17 in magnitudes relative to Vega The distance between star 3 and the edge of the COS aperture is 0.69", figure 7.1 show the throughput is 0.7 ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-1987A-CO COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, BUFFER-TIME=800 1 2072 S S G see below (1883 S) ------------------------------------------------------------------------------------------------------------------------------------ 17496( 9) - 20-Mar-2025 19:22:17 - [ 8] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-1987A-CO COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=800, FP-POS=4 1 3030 S S G see below (2707 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-1987A-CO COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=800, FP-POS=4 1 3030 S S G see below (2707 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN-1987A-CO COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=800, FP-POS=3 1 3030 S S G see below (2707 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN-1987A-COS-ACQ 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE SN-1987A-COS 2 COS/NUV TIME-TA PSA MIRRORB none none none none 1 411.0 S G SN-1987A-COS 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 1883.0 S G SN-1987A-COS 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 2707.0 S G SN-1987A-COS 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 2707.0 S G SN-1987A-COS 6 COS/FUV TIME-TA PSA G130M 1291 none none none none 4 2707.0 S G 17496( 9) - 20-Mar-2025 19:22:17 - [ 9] Visit: 04 Visit Requirements: ORIENT 60.0D TO 90.0 D; SEQ 03, 04 WITHIN 1 D On Hold Comments: Additional Comments: ideal angle is 75. Note that an identical copy of these observations were carried out in Cycle 19. These data will allow us to inspect the relatively temporal variability of the lines and continuum. 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 SN-1987A-CO COS/NUV ACQ/IMA PSA MIRRORB 1 14 S (14 S-ACQ GE S) Comments: COS.A351911 Model ID = 98217 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.03 in magnitudes relative to Vega COS.A351916 Kurucz (B5V): Temp = 15400, I avereage the two.. 12 seconds with B3V, and 16 seconds with B5V ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-1987A-CO COS/NUV TIME-TA PSA MIRRORB BUFFER-TIME=490 1 600 S S G see below (411 S) Comments: star 3: V=15.60 B-V 0.46 U-B -0.89 V = 15.60 B=16.06 U=15.17 B3 star Exposure ID: COS.A331360 If the aperture falls on nearby star 3; COS.A331366 Brightest pixel 16.484 Count rate entire detector 491.586 Exposure time (seconds) = 600.0000 Model ID = 96513 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.17 in magnitudes relative to Vega The distance between star 3 and the edge of the COS aperture is 0.69", figure 7.1 show the throughput is 0.7 ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1577 FP-POS=1, BUFFER-TIME=800 1 1910 S S G see below (1721 S) ------------------------------------------------------------------------------------------------------------------------------------ 17496( 9) - 20-Mar-2025 19:22:17 - [ 10] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=800, FP-POS=2 1 1191 S S G see below (1039 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1600 BUFFER-TIME=800, FP-POS=3 1 1387 S S G see below (1235 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1600 BUFFER-TIME=800, FP-POS=4 1 3034 S S G see below (2711 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1611 BUFFER-TIME=800, FP-POS=3 1 3034 S S G see below (2711 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN-1987A-COS-ACQ 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE SN-1987A-COS 2 COS/NUV TIME-TA PSA MIRRORB none none none none 1 411.0 S G SN-1987A-COS 3 COS/FUV TIME-TA PSA G160M 1577 none none none none 1 1721.0 S G SN-1987A-COS 4 COS/FUV TIME-TA PSA G160M 1577 none none none none 2 1039.0 S G SN-1987A-COS 5 COS/FUV TIME-TA PSA G160M 1600 none none none none 2 1235.0 S G SN-1987A-COS 6 COS/FUV TIME-TA PSA G160M 1600 none none none none 3 2711.0 S G SN-1987A-COS 7 COS/FUV TIME-TA PSA G160M 1611 none none none none 4 2711.0 S G 17496( 9) - 20-Mar-2025 19:22:17 - [ 11] Visit: 05 Visit Requirements: ORIENT 60.0D TO 90.0 D; SEQ 03, 05 WITHIN 1 D On Hold Comments: Additional Comments: ideal angle is 75. Note that an identical copy of these observations were carried out in Cycle 19. These data will allow us to inspect the relatively temporal variability of the lines and continuum. 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 SN-1987A-CO COS/NUV ACQ/IMA PSA MIRRORB 1 14 S (14 S-ACQ GE S) Comments: COS.A351911 Model ID = 98217 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.03 in magnitudes relative to Vega COS.A351916 Kurucz (B5V): Temp = 15400, I avereage the two.. 12 seconds with B3V, and 16 seconds with B5V ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-1987A-CO COS/NUV TIME-TA PSA MIRRORB BUFFER-TIME=490 1 600 S S G see below (411 S) Comments: star 3: V=15.60 B-V 0.46 U-B -0.89 V = 15.60 B=16.06 U=15.17 B3 star Exposure ID: COS.A331360 If the aperture falls on nearby star 3; COS.A331366 Brightest pixel 16.484 Count rate entire detector 491.586 Exposure time (seconds) = 600.0000 Model ID = 96513 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.17 in magnitudes relative to Vega The distance between star 3 and the edge of the COS aperture is 0.69", figure 7.1 show the throughput is 0.7 ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1577 FP-POS=1, BUFFER-TIME=800 1 1910 S S G see below (1721 S) ------------------------------------------------------------------------------------------------------------------------------------ 17496( 9) - 20-Mar-2025 19:22:17 - [ 12] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1600 BUFFER-TIME=800, FP-POS=3 1 3034 S S G see below (2711 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1611 BUFFER-TIME=800, FP-POS=4 1 3034 S S G see below (2711 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN-1987A-COS-ACQ 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE SN-1987A-COS 2 COS/NUV TIME-TA PSA MIRRORB none none none none 1 411.0 S G SN-1987A-COS 3 COS/FUV TIME-TA PSA G160M 1577 none none none none 1 1721.0 S G SN-1987A-COS 4 COS/FUV TIME-TA PSA G160M 1600 none none none none 2 2711.0 S G SN-1987A-COS 5 COS/FUV TIME-TA PSA G160M 1611 none none none none 3 2711.0 S G 17496( 9) - 20-Mar-2025 19:22:17 - [ 13] Visit: 14 Visit Requirements: ORIENT 60.0D TO 130 D; BEFORE 06-SEP-2025:00:00:00 On Hold Comments: Additional Comments: ideal angle is 75. Note that an identical copy of these observations were carried out in Cycle 19. These data will allow us to inspect the relatively temporal variability of the lines and continuum. Repeat of failed visit 04. 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 SN-1987A-CO COS/NUV ACQ/IMA PSA MIRRORB 1 14 S (14 S-ACQ GE S) Comments: COS.A351911 Model ID = 98217 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.03 in magnitudes relative to Vega COS.A351916 Kurucz (B5V): Temp = 15400, I avereage the two.. 12 seconds with B3V, and 16 seconds with B5V ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-1987A-CO COS/NUV TIME-TA PSA MIRRORB BUFFER-TIME=490 1 600 S S G see below (411 S) Comments: star 3: V=15.60 B-V 0.46 U-B -0.89 V = 15.60 B=16.06 U=15.17 B3 star Exposure ID: COS.A331360 If the aperture falls on nearby star 3; COS.A331366 Brightest pixel 16.484 Count rate entire detector 491.586 Exposure time (seconds) = 600.0000 Model ID = 96513 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.17 in magnitudes relative to Vega The distance between star 3 and the edge of the COS aperture is 0.69", figure 7.1 show the throughput is 0.7 ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1577 FP-POS=1, BUFFER-TIME=800 1 1910 S S G see below (1721 S) ------------------------------------------------------------------------------------------------------------------------------------ 17496( 9) - 20-Mar-2025 19:22:17 - [ 14] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1577 BUFFER-TIME=800, FP-POS=2 1 1191 S S G see below (1039 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1600 BUFFER-TIME=800, FP-POS=3 1 1387 S S G see below (1235 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1600 BUFFER-TIME=800, FP-POS=4 1 3034 S S G see below (2711 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1611 BUFFER-TIME=800, FP-POS=3 1 3034 S S G see below (2711 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN-1987A-COS-ACQ 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE SN-1987A-COS 2 COS/NUV TIME-TA PSA MIRRORB none none none none 1 411 S G SN-1987A-COS 3 COS/FUV TIME-TA PSA G160M 1577 none none none none 1 1721.0 S G SN-1987A-COS 4 COS/FUV TIME-TA PSA G160M 1577 none none none none 2 1039.0 S G SN-1987A-COS 5 COS/FUV TIME-TA PSA G160M 1600 none none none none 2 1235.0 S G SN-1987A-COS 6 COS/FUV TIME-TA PSA G160M 1600 none none none none 3 2711.0 S G SN-1987A-COS 7 COS/FUV TIME-TA PSA G160M 1611 none none none none 4 2711.0 S G 17496( 9) - 20-Mar-2025 19:22:17 - [ 15] Visit: 15 Visit Requirements: ORIENT 60.0D TO 130 D; BEFORE 06-SEP-2025:00:00:00 On Hold Comments: Additional Comments: ideal angle is 75. Note that an identical copy of these observations were carried out in Cycle 19. These data will allow us to inspect the relatively temporal variability of the lines and continuum. Repeat of failed visit 05. 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 SN-1987A-CO COS/NUV ACQ/IMA PSA MIRRORB 1 14 S (14 S-ACQ GE S) Comments: COS.A351911 Model ID = 98217 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.03 in magnitudes relative to Vega COS.A351916 Kurucz (B5V): Temp = 15400, I avereage the two.. 12 seconds with B3V, and 16 seconds with B5V ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-1987A-CO COS/NUV TIME-TA PSA MIRRORB BUFFER-TIME=490 1 600 S S G see below (411 S) Comments: star 3: V=15.60 B-V 0.46 U-B -0.89 V = 15.60 B=16.06 U=15.17 B3 star Exposure ID: COS.A331360 If the aperture falls on nearby star 3; COS.A331366 Brightest pixel 16.484 Count rate entire detector 491.586 Exposure time (seconds) = 600.0000 Model ID = 96513 + Kurucz (B3V): Temp = 18700, LogZ = 0.0, Logg = 3.9 . Renormalized to Johnson U = 15.17 in magnitudes relative to Vega The distance between star 3 and the edge of the COS aperture is 0.69", figure 7.1 show the throughput is 0.7 ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1577 FP-POS=1, BUFFER-TIME=800 1 1910 S S G see below (1721 S) ------------------------------------------------------------------------------------------------------------------------------------ 17496( 9) - 20-Mar-2025 19:22:17 - [ 16] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1600 BUFFER-TIME=800, FP-POS=3 1 3034 S S G see below (2711 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-1987A-CO COS/FUV TIME-TA PSA G160M 1611 BUFFER-TIME=800, FP-POS=4 1 3034 S S G see below (2711 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN-1987A-COS-ACQ 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE SN-1987A-COS 2 COS/NUV TIME-TA PSA MIRRORB none none none none 1 411.0 S G SN-1987A-COS 3 COS/FUV TIME-TA PSA G160M 1577 none none none none 1 1721.0 S G SN-1987A-COS 4 COS/FUV TIME-TA PSA G160M 1600 none none none none 2 2711.0 S G SN-1987A-COS 5 COS/FUV TIME-TA PSA G160M 1611 none none none none 3 2711.0 S G 17496( 9) - 20-Mar-2025 19:22:17 - [ 17] Summary Form for Proposal 17496 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA, UVIS2-C1K1C-CTE ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=490, BUFFER-TIME=800, CR-SPLIT=NO, FLASH=10, FLASH=15, FLASH=16, FLASH=5, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 06-SEP-2025:00:00:00, BETWEEN 10-MAY-2024:00:00:00 AND 15-OCT-2024:00:00:00, ORIENT 168D TO 172 D, ORIENT 258D TO 262 D, ORIENT 348D TO 352 D, ORIENT 60.0D TO 130 D, ORIENT 60.0D TO 90.0 D, ORIENT 78D TO 82 D, PATTERN 1 1-3, SEQ 01, 02 WITHIN 14 D, SEQ 03, 04 WITHIN 1 D, SEQ 03, 04 WITHIN 10 D, SEQ 03, 05 WITHIN 1 D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F502N, F625W, F657N, F763M, G130M, G160M, MIRRORB ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN-1987A, SN-1987A-COS, SN-1987A-COS-ACQ ------------------------------------------------------------------------------------------------------------------------------------