15488( 3) - 08-Jun-2018 20:12:57 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15488 Version: 3 Check-in Time: 08-Jun-2018 20:12:57 STScI Edit Number: 1 Title UV Spectroscopy of the Nearby Superluminous Supernova SN2018bsz ------------------------------------------------------------------------------------ Type Cycle GO/DD 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Mr. Peter Blanchard Harvard University Y CoI: Matt Nicholl Harvard University N CoI: Prof. Edo Berger Harvard University N CoI: Prof. Ryan Chornock Ohio University N CoI: Dr. Raffaella Margutti Northwestern University N CoI: Dr. Deanne Coppejans Northwestern University N CoI: Dr. Kate Denham Alexander Northwestern University N CoI: Dr. Dan Milisavljevic Purdue University N CoI: Giacomo Terreran Northwestern University N ------------------------------------------------------------------------------------ Abstract The latest generation of wide-field time-domain surveys has led to the discovery of rare, extreme transients such as superluminous supernovae (SLSNe). Recently, exotic power sources such as a magnetar central engine have gained traction as a plausible explanation for their enormous luminosities. However, due to their low volumetric rates, only a handful of SLSNe have been discovered at z < 0.1 where the effects of the power source can be probed in the greatest detail. A key region of the spectrum for testing the effects of various proposed power sources is the UV, where the spectral energy distributions peak. Fully understanding the UV characteristics and diversity revealed by ground-based observations of high-redshift events and HST observations of low-redshift events requires additional observations. Here we propose to obtain FUV and NUV observations with HST of SN2018bsz at a redshift of z = 0.026, the nearest SLSN discovered to date. In addition to one epoch of FUV+NUV observations, we request two additional epochs of NUV observations to monitor the UV evolution. SN2018bsz provides an exellent opporunity to obtain high signal-to-noise UV spectroscopy that can be compared with other events with UV spectra and with radiative transfer models. Characterizing the UV spectra of low-z SLSNe with HST is critical for understanding the rest-frame UV spectra of future events that will be discovered at z > 1 with upcoming surveys such as LSST. ------------------------------------------------------------------------------------ Observations Description ------------------------ We request a single visit with 2 orbits of COS/FUV and 1 orbit of STIS/NUV. ------------------------------------------------------------------------------------ 15488( 3) - 08-Jun-2018 20:12:57 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2018BSZ EXT-STAR, SUPERNOVA RA=16H09M39.1100S +/- 0.2", J2000 V = 16.03 U = 15.50, UVW1 = 15.51, UVM2 DEC=-32D03'45.63" +/- 0.2" = 16.05, UVW2 = 16.42 Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 15488( 3) - 08-Jun-2018 20:12:57 - [ 3] Visit: 01 Visit Requirements: BEFORE 02-JUL-2018:00:00:00 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 SN2018BSZ COS/NUV ACQ/IMA PSA MIRRORB 1 70 S (70 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2018BSZ COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=6000, FP-POS=ALL, 1 532 S G FLASH=YES (2128 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2018BSZ COS/FUV TIME-TA PSA G140L 1105 BUFFER-TIME=6000, FP-POS=ALL, 1 659 S G FLASH=YES (2636 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2018BSZ STIS/CCD ACQ F28X50LP MIRROR 1 15 S (15 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2018BSZ STIS/NUV ACCUM 52X0.2 G230L 2376 1 2378 S -MAMA (2378 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2018BSZ 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A GE SN2018BSZ 2 COS/FUV TIME-TA PSA G140L 1105 none none none 1 1 N/A G SN2018BSZ 2 COS/FUV TIME-TA PSA G140L 1105 none none none 2 1 N/A G SN2018BSZ 2 COS/FUV TIME-TA PSA G140L 1105 none none none 3 1 N/A G SN2018BSZ 2 COS/FUV TIME-TA PSA G140L 1105 none none none 4 1 N/A G SN2018BSZ 3 COS/FUV TIME-TA PSA G140L 1105 none none none 1 2 N/A G SN2018BSZ 3 COS/FUV TIME-TA PSA G140L 1105 none none none 2 2 N/A G SN2018BSZ 3 COS/FUV TIME-TA PSA G140L 1105 none none none 3 2 N/A G SN2018BSZ 3 COS/FUV TIME-TA PSA G140L 1105 none none none 4 2 N/A G SN2018BSZ 4 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2018BSZ 5 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 3 N/A -MAMA 15488( 3) - 08-Jun-2018 20:12:57 - [ 4] Summary Form for Proposal 15488 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2, F28X50LP, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV, STIS/CCD, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=6000, FLASH=YES, FP-POS=ALL ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 02-JUL-2018:00:00:00 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, G230L, MIRROR, MIRRORB ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN2018BSZ ------------------------------------------------------------------------------------------------------------------------------------