Changed Observation 1 to Disruptive on advice from Brett Blacker. 480868277 Assigned ID: 224 ----- Attempting Submission 1 (Thu Apr 04 17:18:45 GMT 2019) ----- HST Phase I Proposal 224 (fox_hst27_ibn_v1.apt) successfully submitted. Receipt: # 224-1 ----- Attempting Submission 2 (Fri Apr 05 16:21:59 GMT 2019) ----- HST Phase I Proposal 224 (fox_hst27_ibn_v1.apt) successfully submitted. Receipt: # 224-2 ----- Attempting Submission 3 (Fri Apr 05 22:23:43 GMT 2019) ----- HST Phase I Proposal 224 (fox_hst27_ibn_v1.apt) successfully submitted. Receipt: # 224-3 ----- Attempting Submission 4 (Fri Apr 05 22:47:51 GMT 2019) ----- HST Phase I Proposal 224 (fox_hst27_ibn_v1.apt) successfully submitted. Receipt: # 224-4 ----- Attempting Submission 5 (Fri Apr 05 23:12:04 GMT 2019) ----- HST Phase I Proposal 224 (fox_hst27_ibn_v1.apt) successfully submitted. Receipt: # 224-5 ----- Attempting Submission 6 (Fri Apr 05 23:26:24 GMT 2019) ----- HST Phase I Proposal 224 (fox_hst27_ibn_v1.apt) successfully submitted. Receipt: # 224-6 ----- Attempting Submission 7 (Fri Apr 05 23:50:32 GMT 2019) ----- HST Phase I Proposal 224 (fox_hst27_ibn_v1.apt) successfully submitted. Receipt: # 224-7 ----- Attempting Submission 8 (Sat Apr 06 12:32:16 GMT 2019) ----- This target is not used in this proposal. This pattern is not used in this proposal. Split visit 4 in 3 seperate visits. -1413986194 ----- Attempting Submission 1 (Fri Jul 26 00:14:05 GMT 2019) ----- HST Phase II Proposal 15834 (fox_hst27_ibn_PHASE2_v1.apt) successfully submitted. Receipt: # 15834-1 ----- Attempting Submission 2 (Fri Jul 26 00:26:44 GMT 2019) ----- ----- Attempting Submission 3 (Thu Jul 16 17:17:34 GMT 2020) ----- HST Phase II Proposal 15834 successfully submitted. Receipt: # 15834-3 ----- Attempting Submission 4 (Thu Jul 16 20:14:37 GMT 2020) ----- HST Phase II Proposal 15834 successfully submitted. Receipt: # 15834-4 ----- Attempting Submission 5 (Thu Jul 16 22:18:30 GMT 2020) ----- Not using this pattern since we're not using any dithers. But keeping it in APT just in case. Type Ibn supernovae (SNe Ibn) are a rare (<1%) core-collapse SN subclass that exhibits hydrogen-poor (e.g., stripped-envelope Type Ib) spectra dominated by narrow helium features that arise from a slow-moving, pre-existing, dense circumstellar medium (CSM). Compared to other SN subclasses, the light curves tend to be brighter and rise/decline faster. These unique properties leave a number of outstanding unknowns, such as progenitor system and powering mechanism. Increasing the intrigue, SNe Ibn are now linked to an even lesser well-known set of explosions known as Fast Blue Optical Transients (FBOTs), which have been suggested to harbor tidal disruption events and/or magnetars. The UV offers an opportunity to determine the true nature of the SN Ibn subclass given its sensitivity to spectral line diagnostics that can constrain the progenitor mass-loss history and CNO processing. Yet given the low rates and fast decline of SNe Ibn (and FBOTs), UV spectroscopy is limited to just two SNe Ibn (and zero FBOTs), and these spectra are of limited use because they (a) do not extend into the far-UV and (b) are either low-resolution or low signal-to-noise ratio. Here we propose a disruptive ToO with HST/STIS to obtain 2 epochs of UV spectra of a SN Ibn within 250 Mpc. This program will not only distinguish between the Type Ibn progenitors and powering mechanisms, but will also provide clues about the nature of FBOTs. Coinciding with Cycle 27's UV Initiative, this program opens up new phase space in our study of the progenitor and explosion characteristics of the SN Ibn subclass. We propose to obtain 2 epochs (3 orbits each) of STIS-MAMA spectra of a single Type Ibn supernova. The brightness is really the most important factor, but SNe Ibn can vary in brightness substantially (magnitudes). We offer rough guidelines of a target within 250 Mpc and as close to light-curve maximum as possible (preferably pre-max). The goal is to detect UV signatures that can distinguish between progenitor scenarios. These observations will also trace circumstellar interaction, constrain the progenitor mass loss, and identify late-time heating mechanisms for potential warm dust. The initial spectrum will be triggered as a *disruptive* ToO, and observations should be scheduled as soon as possible. The second epoch should be obtained again within 10 days (the goal is to maximize the time between the two epochs, so there may be some wiggle room depending on the brightness and evolution timeline of the SN). We will use the data to trace circumstellar interaction, constrain the progenitor mass loss, and measure the CNO processing. Comparisons to other SN and FBOT subclasses will also help distinguish between progenitor systems and central engine powering mechanisms. The first epoch will include observations in both the G140 and G230L bandpasses. The second epoch will include observations in only the G230L bandpass. We choose STIS over COS for several reasons. Most importantly, STIS offers spatially resolved spectra that exploit the intrinsically high resolution of HST over a large spectral range (accommodating both the C III] 1909 Ang and Mg II 2800 Ang lines). The long slit length will allow us to subtract contamination from zodiacal light, earthshine, the host galaxy, and H II regions. STIS also has superior sensitivity to COS in the NUV. While COS is optimized for isolated, faint point sources in the FUV with medium resolution, we would suffer from less wavelength coverage and require more integrations. We would also lose the advantages of the slit described above. Our team consists of experts ranging from theory to observation. We describe each team member's strength below. PI Dr. Ori Fox is an expert in SNe with shock interaction. He was the first author of Fox & Smith (2019), which linked SNe Ibn to FBOTs. He has extensive experience with HST and has previously obtained HST UV spectra. A COS UV spectrum of SN 1993J resulted in Fox et al. (2014), a popular paper that detected the first surviving companion to a SN progenitor. He has also successfully obtained STIS spectra of two SNe IIn (2005ip and 2010jl). This work has resulted in a paper that is very near to submission to ApJ. For observation, data reduction, and analysis: Dr. Jennifer Andrews is an expert observer. With approved time on MMT, she will lead ground-based MMT spectroscopic observations, reduction, and analysis; assessment of spectral features indicative of interstellar extinction. Mr. Tom Brink has much experience obtaining and reducing ground-based spectra, and complementary data of this type will be obtained for the program. Dr. Peter Brown is an expert in Swift UV photometry and spectroscopy of SNe. He will be leading the Swift photometry follow-up portion of this project. Professor Geoffrey Clayton is an expert in modeling SN shock interaction. Professor Alex Filippenko has approved time on Keck and Lick that can provide for any necessary supporting ground-based observations. Dr. Griffin Hosseinzadeh is an expert in SNe Ibn. He wrote the recent compilation paper defining all the properties of the subclass (Hosseinzadeh et al. 2017). Professor Pat Kelly has long studied the properties of host galaxies of SNe. Dr. Jon Mauerhan is an expert on spectropolarimetry (completementary data that we plan to obtain with ground-based telescopes) and has much experience regarding the properties of massive stars. Dr. Adam Miller is a member of the Zwicky Transient Facility, which will help us identify and type SNe Ibn early. Professor Nathan Smith is an expert in the properties and evolution of massive stars, and on spectroscopy of SNe. Dr. Tamas Szalai is an expert in SN dust and infrared observations, which has proven to be an important aspect of some SNe Ibn (like SN 2006jc). Dr. Schuyler Van Dyk is an expert in HST photometry of SNe and in the study of stripped-envelope SNe. Dr. WeiKang Zheng is an expert at CCD imaging and photometry of SNe, both ground-based and HST; he will construct multifilter light curves of the object. For theory, modeling, and interpretation: Professor Roger Chevalier is an expert in modeling SN shock interaction with the circumstellar medium. Professor Claes Fransson is an expert in modeling SN shock interaction. He led papers on STIS spectra of several SNe IIn (Fransson et al., 2002, 2005, 2014). Dr. Jose Groh is an expert at modeling SN shock interaction, particularly with CMFGEN, which we are proposing to use in this proposal. He has done similar work before (Groh et al. 2014, Boian & Groh, 2019), and will now implement the same analysis on SNe Ibn. Stellar Physics 6 false false true false false false false SUPPORTED STAR SUPERNOVA TYPE IB NO J2000 In the case where we may not have swift observations but the Type Ibn apppears very bright in ground-based optical observations (v~15), we may also decide to trigger. Type Ibn within about 250 Mpc and near maximum (preferably 2 days pre-max). We would ideally use Swift to justify a UMVM2 (approximately F218W bandpass) of brighter than -21 (or apparent magnitude around 16). STIS/FUV-MAMA Spectroscopic No No G140L 1425 STIS/NUV-MAMA Spectroscopic No No G230L 2376 STIS/NUV-MAMA Spectroscopic No No G230L 2376 POS-TARG DITHER 0.264 LINE false true 2 90.0 STIS-ALONG-SLIT 1 false 1594931438099 /private/var/folders/yh/kl4y3s1x3_j3ywy3qq67g3vc0001kc/T/OPVisit361636701145659352.xml Timing link suitability includes constraints ([02 After 01 by at most 0.1 days] [04 After 01 by 6.0 to 12.0 days]) The scheduling data was generated by CASM 28.2. CASM was run in Phase II mode. Likely to acquire on bright SN. (Tic-Visit :proposal-id 15834 :visit-id "01" :proposal-version -1 :trans-version "20200518" :date "16-Jul-2020 16:30:38.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 87408 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15834 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15834 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2326 :al-overhead-at-end 0 :internal-dur-at-end 394 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0 Target-of-Opportunity. The initial spectrum will be triggered as a disruptive ToO, and observations should be scheduled as soon as possible (2-5 days as stated in the CfP). Less than 2 days could be possible since PI Fox works at STScI and has worked on ultra-rapid responses with HST planners in the past. The main goal, however, is to make sure the observations are obtained around peak, which typically happens about 3 days post-discovery. Used 10,000K Blackbody normalized to V=16. SN should be bright during initial acquisition. Assuming a 10,000K Blackbody around peak. 1594930256173 /Users/ofox/Work/proposals/hubble/Cycle27/Ibn/OP-cache/2020nxt_FUV_v3-v02.xml Timing link suitability includes constraints ([02 After 01 by at most 0.1 days] [03 After 02 by at most 0.1 days]) The scheduling data was generated by CASM 28.2. CASM was run in Phase II mode. Likely to acquire on bright SN. (Tic-Visit :proposal-id 15834 :visit-id "02" :proposal-version -1 :trans-version "20200518" :date "16-Jul-2020 16:10:56.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 87408 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15834 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15834 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2326 :al-overhead-at-end 0 :internal-dur-at-end 394 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0 Target-of-Opportunity. The initial spectrum will be triggered as a disruptive ToO, and observations should be scheduled as soon as possible (2-5 days as stated in the CfP). Less than 2 days could be possible since PI Fox works at STScI and has worked on ultra-rapid responses with HST planners in the past. The main goal, however, is to make sure the observations are obtained around peak, which typically happens about 3 days post-discovery. Used 10,000K Blackbody normalized to V=16. SN should be bright during initial acquisition. Assuming a 10,000K Blackbody around peak. 1594930256661 /Users/ofox/Work/proposals/hubble/Cycle27/Ibn/OP-cache/2020nxt_FUV_v3-v03.xml Timing link suitability includes constraints ([03 After 02 by at most 0.1 days]) The scheduling data was generated by CASM 28.2. CASM was run in Phase II mode. Likely to acquire on bright SN. (Tic-Visit :proposal-id 15834 :visit-id "03" :proposal-version -1 :trans-version "20200518" :date "16-Jul-2020 16:10:56.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 87408 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15834 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15834 :visit-id "03" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2326 :al-overhead-at-end 0 :internal-dur-at-end 394 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0 Target-of-Opportunity. The initial spectrum will be triggered as a disruptive ToO, and observations should be scheduled as soon as possible (2-5 days as stated in the CfP). Less than 2 days could be possible since PI Fox works at STScI and has worked on ultra-rapid responses with HST planners in the past. The main goal, however, is to make sure the observations are obtained around peak, which typically happens about 3 days post-discovery. Used 10,000K Blackbody normalized to V=16. SN should be bright during initial acquisition. Assuming a 10,000K Blackbody around peak. 1594931496322 /private/var/folders/yh/kl4y3s1x3_j3ywy3qq67g3vc0001kc/T/OPVisit17101411326193893352.xml Timing link suitability includes constraints ([04 After 01 by 6.0 to 12.0 days] [05 After 04 by at most 0.1 days]) The scheduling data was generated by CASM 28.2. CASM was run in Phase II mode. Likely to acquire on bright SN. (Tic-Visit :proposal-id 15834 :visit-id "04" :proposal-version -1 :trans-version "20200518" :date "16-Jul-2020 16:31:36.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 87408 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15834 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15834 :visit-id "04" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2729 :al-overhead-at-end 0 :internal-dur-at-end 394 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0 Target-of-Opportunity. This visit will be scheduled for 6-12 days following the first visit (as specified in the Timing Requirements), ideally aiming for 10 days. But we'd like to have some flexibility with our final submission to account for the brightness and light-curve evolution. Used 10,000K Blackbody normalized to V=16. SN should be bright during initial acquisition. Assuming a 7,000K Blackbody around 10 days post-max. 1594931497369 /private/var/folders/yh/kl4y3s1x3_j3ywy3qq67g3vc0001kc/T/OPVisit3006192153343566157.xml Timing link suitability includes constraints ([05 After 04 by at most 0.1 days] [06 After 05 by at most 0.1 days]) The scheduling data was generated by CASM 28.2. CASM was run in Phase II mode. Likely to acquire on bright SN. (Tic-Visit :proposal-id 15834 :visit-id "05" :proposal-version -1 :trans-version "20200518" :date "16-Jul-2020 16:31:37.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 87408 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15834 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15834 :visit-id "05" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2729 :al-overhead-at-end 0 :internal-dur-at-end 394 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0 Target-of-Opportunity. This visit will be scheduled for 6-12 days following the first visit (as specified in the Timing Requirements), ideally aiming for 10 days. But we'd like to have some flexibility with our final submission to account for the brightness and light-curve evolution. Used 10,000K Blackbody normalized to V=16. SN should be bright during initial acquisition. Assuming a 7,000K Blackbody around 10 days post-max. 1594931498416 /private/var/folders/yh/kl4y3s1x3_j3ywy3qq67g3vc0001kc/T/OPVisit3204474778235105396.xml Timing link suitability includes constraints ([06 After 05 by at most 0.1 days]) The scheduling data was generated by CASM 28.2. CASM was run in Phase II mode. Likely to acquire on bright SN. (Tic-Visit :proposal-id 15834 :visit-id "06" :proposal-version -1 :trans-version "20200518" :date "16-Jul-2020 16:31:38.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 87408 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15834 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15834 :visit-id "06" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2729 :al-overhead-at-end 0 :internal-dur-at-end 394 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3200 :pcs-gap 0 ) true 1 0 Target-of-Opportunity. This visit will be scheduled for 6-12 days following the first visit (as specified in the Timing Requirements), ideally aiming for 10 days. But we'd like to have some flexibility with our final submission to account for the brightness and light-curve evolution. Used 10,000K Blackbody normalized to V=16. SN should be bright during initial acquisition. Assuming a 7,000K Blackbody around 10 days post-max.