0 Assigned ID: 2010 ----- Attempting Submission 1 (Fri Apr 09 16:36:01 GMT 2021) ----- HST Phase I Proposal 2010 successfully submitted. Receipt: # 2010-1 ----- Attempting Submission 2 (Fri Apr 09 16:55:14 GMT 2021) ----- HST Phase I Proposal 2010 successfully submitted. Receipt: # 2010-2 ----- Attempting Submission 3 (Fri Apr 09 22:45:27 GMT 2021) ----- HST Phase I Proposal 2010 successfully submitted. Receipt: # 2010-3 ----- Attempting Submission 4 (Fri Apr 09 23:54:49 GMT 2021) ----- SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE SAME POS MAY NOT BE APPROPRIATE 0 ----- Attempting Submission 1 (Mon Jul 26 15:25:07 GMT 2021) ----- We use the option "SAME POS" to ensure that the pair-wise imaging and spectroscopy observations have no offsets. What powers the longest-rising superluminous supernova 2020abjc? Super-luminous supernovae (SLSNe) are rare stellar explosions whose explosion mechanism and source of immense luminosity are not well established. SN2020abjc is the longest-lasting SLSN known. Its properties are extreme, even for slow-evolving SLSNe. Its spectrum shows no sign of interaction of the SN ejecta with a circumstellar medium and its light curve (shape and colour) rejects a central engine such as a magnetar. We are thus left with the conclusion that a long-lasting light curve equals a long diffusion time, which again requires a very high total mass. The pair-instability-supernova (PISN) mechanism naturally provides both the energy source (a lot of Ni) and the long diffusion time (large mass). Could SN2020abjc be a PISN? We propose to obtain slitless near-IR spectroscopy with WFC3/IR and the G102 and G141 grisms to measure the amount of iron, sulphur, silicon and helium in the ashes of the SN progenitor. This will enable us to unveil the explosion mechanism and the progenitor of this unusual SLSN. Our goal is to obtain grism spectroscopy of a superluminous supernova with WFC3/IR using both the G102 and G141 grisms. Our proposal consists of: -2 visits of WFC3/IR spectroscopy comprising of one orbit in G102 and G141 each. The zeroth-order image are obtained with F105W and F140W. -Each orbit is divided as follows [image, grism] ..dither.. [image, grism] ..dither.. [grism, image] ..dither.. [grism, image]. -Each observations is labelled as GRISM-[102|141]-OR[1|2|3|4]-V[1|2][a|b|c|d]-[PREIM|SPEC]: [102|141] specifies the grism ID OR[1|2|3|4] specifies the orbit number V[1|2][a|b|c|d] specifies the whether this is the first or second visit and the position in the 4-point dither sequence [PREIM|SPEC] specifies whether this the zeroth-order or spectroscopic observation -We wish the second orientation to be offset from the first, but still within these original constraints. This is to avoid contamination of the spectrum by fainter sources we have not detected yet. We have set this offset from orbit 1 to 30 to 150 degree. -We have no further scheduling constraints on the two visits, i.e., visit 1 and 2 can be weeks or even months apart. Our team consists of early-carrer and senior postdocs and well-established professors in the field of core-collapse supernovae. In the past 5 years, our team has published over 30 papers (as first authors) on supernovae, extragalactic transients and galaxies in refereed journals (including 1 article in Nature), i.e., the overwhelming majority of papers on SLSNe. The topics of our research on SLSNe include but are not limited to observational properties of SLSN light curves and spectra, polarisation measurements, the theoretical modelling of SLSNe, as well as SLSN host galaxies. The scientific questions we addressed in these papers focus on: i) identifying the progenitors of SLSNe, ii) identifying which sources of energy power the explosions, iii) the physical processes that give rise to these brilliant explosions, iv) using SLSNe for cosmology, and v) SLSNe as probes of cosmic star-forming beyond the limits of classical galaxy surveys. A cornerstone of our team's success is to acquire observing time at premiere class observatories. This also includes UV, optical and NIR imaging and spectroscopy with HST. Specifically, the individual team members will contribute to: -Proposal preparation: All -Planning the observations: S. Schulze, L. Yan, Y. Yang. T. Kangas -Reducing the data: T. Kangas, R. Lunnan, D. Perley, L. Yan, O. Yaron -Interpreting the spectra and light curves: A. Gal-Yam, C. Fransson, T. Kangas, R. Lunnan, D. Perley, S. Schulze, J. Sollerman, L. Yan, O. Yaron Stellar Physics and Stellar Types 6 false false false false false false false false SUPPORTED EXT-STAR SUPERNOVA NO SN2020ABJC J2000 J2000 WFC3/IR Spectroscopic No No G102 WFC3/IR Spectroscopic No No G141 WFC3/IR Imaging No No F105W WFC3/IR Imaging No No F140W The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. /Volumes/Home/steve/Downloads/OP-cache/SN2020abjc - HST 16766 - NIR spec - Phase 2 - 20210720-v01.xml Grism and pre-imaging visit 1 4 x (100s preimaging + 500s grism) in G102 and G141 each order: preim, grism, preim, grism, grism, preim, grism, preim (to minimise HeI at end of orbit) 4 position dither pattern plus -1", -1" offset (Tic-Visit :proposal-id 16766 :visit-id "01" :proposal-version -1 :trans-version "20210514" :date "26-Jul-2021 16:52:25.0" :trans-errors '(:WARNINGS 8 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2472064 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16766 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16766 :visit-id "01" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2720 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16766 :visit-id "01" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2742 :al-overhead-at-end 0 :internal-dur-at-end 671 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. /Volumes/Home/steve/Downloads/OP-cache/SN2020abjc - HST 16766 - NIR spec - Phase 2 - 20210720-v02.xml Grism and pre-imaging visit 2 4 x (100s preimaging + 500s grism) in G102 and G141 each order: preim, grism, preim, grism, grism, preim, grism, preim (to minimise HeI at end of orbit) 4 position dither pattern plus -1", -1" offset (Tic-Visit :proposal-id 16766 :visit-id "02" :proposal-version -1 :trans-version "20210514" :date "26-Jul-2021 16:52:28.0" :trans-errors '(:WARNINGS 8 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2472064 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16766 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16766 :visit-id "02" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2720 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16766 :visit-id "02" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2742 :al-overhead-at-end 0 :internal-dur-at-end 671 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) true 2 0 Updated preimaging after results of V1