0 Assigned ID: 2576 ----- Attempting Submission 1 (Wed Sep 29 18:04:47 GMT 2021) ----- Resubmission following failure of Visit 4. Visit 6 is a direct replacement, with relaxation of the timing constraint. Two visiting to be observed (5 + 6) have a window over the next several weeks. These visits will be separated by at least 10 days from each other as we want to measure presence of relatively long-term variability in the source. The failure of visit 4 means the reminaing window (whilst obeying ORIENT constraints) is now quite restricted for these conditions. Please let me know if there are any scheuling issues. Visits 1 and 2 contain two orbits, each of a different filter. These 4-filter observations are to be used to create an SED of a varying sources and would ideally occur within a single visit. However, we have split them to aid scheduling and grouped them so they are still taken close together in time. Visits 3-5 are single orbit visits in a single filter spread over the cycle to monitor the variability. All observations are to be taken with somewhat particular angle constraints to match previous imaging, and to avoid the effects of diffraction spikes from bright sources nearby. NIR observations don't use quite the full orbit but are fixed to match exactly the observing setup of previous observations and improve scheduling. Scheduability of UVIS orbit has been increased to allow for window in early 2022. I would appreciate advice on if the FLASH=10 is a good choice for the UVIS observation. FLASH=20 raised a warning that it would be overkill. 358219843 ----- Attempting Submission 1 (Fri Dec 03 09:56:23 GMT 2021) ----- ----- Attempting Submission 2 (Tue Dec 14 09:45:47 GMT 2021) ----- ----- Attempting Submission 3 (Thu Aug 25 20:13:53 GMT 2022) ----- The origin of NIR emission in the Fast radio burst source SGR 1935+2154 SGR 1935+2154 is a notoriously active magnetar undergoing a period of high energy activity. Similar recent activity in 2020 elicited a series of Fast Radio Burst (FRB) like events from the source and triggered a breakthrough in our understanding of extragalactic FRB progenitors. FRBs are one of the key mysteries of recent astrophysics, and SGR 1935+2154 represents our chance to study the systems that produce them in unprecedented detail. HST has already contributed significantly to this goal - a near-infrared detection of the source has been made and observed to undergo significant variability. Here we propose to capitalise on results from the most recent sighting by HST of the NIR counterpart, which has brightened by a factor of 4, to probe the origin of this emission. The origin of optical and NIR emission from magnetars is poorly known. Models range from fallback of material from a disc and magnetosphere-powered emisson, to surviving binary companions. Each has implications for the formation of magnetars and the nature of the emission is crucial to understand in order to motivate and inform future multi-wavelength follow-up of FRBs. Our proposed observations will obtain a NIR spectral energy distribution for SGR 1935+2154, to be readily compared with models for the emission, in order to uncover its origin. We will also enact a cycle-long monitoring campaign to double the epochs of observations for this object, in order to properly understand the nature of its variability, and its correlation (or lack of) with activity at both higher and lower frequencies. The aim of this proposal is to obtain observations of SGR 1935+2154 to obtain further detections of its counterpart in multiple filters and refine the measurement of its proper motion and determine the level of variability. The source was found to be somewhat brighter in June 2021, and the source is known to vary. This motivates strongly a need to observe the visit to determine its SED as soon as possible (while the source is bright). We have scheduled these as 4xone-orbit visits, with time window between them in order to minimise the variability between these epochs. For further observations, we aim to refine proper motion constraints and pin down the level of variability, and so there is also a significant advantage to matching the orient of the observations with those taken previously, or orientating at 90degree intervals. We will repeat the observational set-up previously used which is a simple 4-point dither pattern using the STEP reads for dynamic range. Lyman has extensive expertise with HST photometry and astrometry, in particular for the study of transients. They have analysed the existing HST data and have the tools ready to rapidly analyse these data. Levan is an expert on the use of HST to study all manner of astrophysical transients. They have published on SGR 1935+2154 using their HST data, along with Kouveliotou and Fruchter. Chrimes is an expert on GRBs and FRBs, as well as a the population synthesis of their progenitor populations. Kouveliotou is a leading expert on neutron stars and magnetars. Wiersema is an expert in the sudy of astrophysical transients and high-energy observations. Fruchter is an expert in the use of HST to explore astrophysical transients and their host galaxies. Stellar Physics and Stellar Types 3 false false false false false true false SUPPORTED STAR NEUTRON STAR This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 F140W = 24.5mag WFC3/IR Imaging No No F105W WFC3/IR Imaging No No F125W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F814W WFC3/IR Imaging No No F140W WFC3/IR Imaging No No F140W WFC3/IR Imaging No No F140W POS-TARG DITHER 0.572 LINE 0.365 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 1 false POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 2 false /home/jdl/research/props/SGR1935_HST29_MC/OP-cache/SGR1935_HST29_MC_phaseII_resubmit_after_4_failed-v01.xml Timing link suitability includes constraints ([Group (01 02) Within 5.0 days]) The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. Visit to obtain part of NIR SED of a varying object. Grouped to other visits that should be completed in a small time-window to minimise impact of variability. 1645953683000 293.7 (Tic-Visit :proposal-id 16883 :visit-id "01" :proposal-version -1 :trans-version "20220516" :date "25-Aug-2022 12:09:15.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2060256 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16883 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16883 :visit-id "01" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2697 :al-overhead-at-end 123 :internal-dur-at-end 31 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3146 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16883 :visit-id "01" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2624 :al-overhead-at-end 0 :internal-dur-at-end 443 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3146 :pcs-gap 0 ) true 2 0 /home/jdl/research/props/SGR1935_HST29_MC/OP-cache/SGR1935_HST29_MC_phaseII_resubmit_after_4_failed-v02.xml Timing link suitability includes constraints ([Group (01 02) Within 5.0 days]) The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. Visit to obtain part of NIR SED of a varying object. Grouped to other visits that should be completed in a small time-window to minimise impact of variability. 1645965116000 293.7 (Tic-Visit :proposal-id 16883 :visit-id "02" :proposal-version -1 :trans-version "20220516" :date "25-Aug-2022 12:09:13.0" :trans-errors '(:WARNINGS 0 :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 1810496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16883 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16883 :visit-id "02" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2624 :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 3157 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16883 :visit-id "02" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2624 :al-overhead-at-end 0 :internal-dur-at-end 690 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3157 :pcs-gap 0 ) true 2 0 /tmp/OPVisit917499875667370573.xml The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. Visit for single observation in F140W at 90deg angle to previous observations for variability and proper motion study 1654528266000 205.218 (Tic-Visit :proposal-id 16883 :visit-id "03" :proposal-version -1 :trans-version "20220516" :date "25-Aug-2022 12:09:11.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 905248 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16883 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16883 :visit-id "03" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2624 :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 3157 :pcs-gap 0 ) true 1 0 /tmp/OPVisit6706134033589956925.xml The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. Visit for single observation in F140W at 90deg angle to previous observations for variability and proper motion study 1660728968000 115.21800000000002 (Tic-Visit :proposal-id 16883 :visit-id "04" :proposal-version -1 :trans-version "20220516" :date "25-Aug-2022 12:21:49.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 905248 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16883 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16883 :visit-id "04" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2624 :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 3157 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([06 After 05 by 10.0 to 40.0 days]) The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. /home/jdl/research/props/SGR1935_HST29_MC/OP-cache/SGR1935_HST29_MC_phaseII_resubmit_after_4_failed-v06.xml Replacement for failed visit 4. Visit for single observation in F140W at 90deg angle to previous observations for variability and proper motion study (Tic-Visit :proposal-id 16883 :visit-id "06" :proposal-version -1 :trans-version "20220516" :date "25-Aug-2022 12:14:30.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 905248 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16883 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16883 :visit-id "06" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2624 :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 3157 :pcs-gap 0 ) true 1 0 /home/jdl/research/props/SGR1935_HST29_MC/OP-cache/SGR1935_HST29_MC_phaseII_resubmit_after_4_failed-v05.xml Timing link suitability includes constraints ([06 After 05 by 10.0 to 40.0 days]) The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. Visit for single observation in F140W at 90deg angle to previous observations for variability and proper motion study (Tic-Visit :proposal-id 16883 :visit-id "05" :proposal-version -1 :trans-version "20220516" :date "25-Aug-2022 12:20:38.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 905248 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16883 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16883 :visit-id "05" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2624 :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 3157 :pcs-gap 0 ) true 1 0