Submitted by Isaac Shivvers, Apr. 10, 2:15 PDT. 982730795 Assigned ID: 260 ----- Attempting Submission 1 (Thu Apr 10 21:18:22 GMT 2014) ----- LONG STIS MAMA SU LIKELY TO INTERSECT THE SAA Updates to exposure times. -472779150 ----- Attempting Submission 1 (Wed Jul 23 19:59:55 GMT 2014) ----- ----- Attempting Submission 2 (Tue Mar 31 20:25:42 GMT 2015) ----- ----- Attempting Submission 3 (Tue Mar 31 22:12:26 GMT 2015) ----- We request a minor exception to the 5-orbit limit for STIS/MAMA visits -- our phase II proposal includes a single visit of 6 orbits. In an email correspondance our support scientist and our program coordinator indicated that this should be possible, contingent on the exact location of our yet-to-be-identified target. Early-Time UV Spectroscopy of Stripped-Envelope Supernovae: A New Window We propose to continue our Cycle 19 and 20 Target-of-Opportunity (ToO) programs to obtain three early-time UV spectra of a stripped-envelope core-collapse supernova (SN Ib or SN Ic), starting well before maximum brightness. The underlying nature of these objects, from the mass-loss process stripping the envelope to the details of the explosion mechanism, remain mysterious. Connections to gamma-ray bursts and X-ray flashes further motivate this study. Many high-redshift SNe are being found in deep transient surveys, but the ability to distinguish between thermonuclear Type Ia SNe and stripped-envelope core-collapse SNe requires thorough knowledge of the latter at UV wavelengths. By comparing the evolution of the spectra as the photosphere recedes to deeper layers of the ejecta with our time series of spectral models, we will gain a better understanding of the explosion, and possibly of the progenitor star. Specifically, we may be able to determine the metal content of the progenitor through comparisons with our spectral models, and we should be able to probe the degree of mixing during the explosion. The heterogeneity seen in stripped-envelope SNe will allow us to choose objects with different characteristics than the ones observed in Cycles 19-20, gaining further insights into this unique class of cosmic explosion. We need to seize this opportunity now, while we still have access to the space UV, and indeed the UV is the Cycle 22 priority of HST. Obtain STIS UV spectra of one bright (Vmax < 15.5 mag), nearby, stripped-envelope SN as soon as possible after discovery (preferably at t < -6 d, relative to maximum brightness), with subsequent spectra just before and just after maximum, for a total of 3 epochs (16 orbits). The cadence of the spectral observations has been determined from the timescale over which significant changes are observed in ground-based optical/near-UV spectra. -------- Realtime Justification -------- This is a disruptive ToO observation of a single bright SN. However, it is not an ultra-rapid (< 2 day turnaround) ToO. We will work with STScI staff to expedite the observations, and we will try to choose an object that minimizes the time between ToO activation and observations. If our object is found 14 days before maximum brightness, and we have a turnaround time of 8 days (i.e., significantly longer than the 2-5 day minimum), the first observation will commence about 6 days before maximum light. We will use both the STIS/CCD and MAMA detectors to provide full wavelength coverage. The CCD observations can be done during the final MAMA orbit of each epoch. The requirement that such observations be split into separate visits presents a substantial problem for our program. The spectra of SNe change rapidly (on a time scale of 1-2 days) at these early phases; temporally separating pieces of the spectrum might seriously compromise our ability to model it. Our program would greatly benefit if the whole spectrum were obtained in a single visit, as was the case in our Cycle 19 and 20 programs. Therefore, we once again request an exception to this rule, a possibility explicitly mentioned in Section 2.6 of the STIS Instrument Handbook. We hope to split our 16 allocated orbits between 3 total visits, which means that we will require a visit of 6 orbits using STIS/MAMA. This is discouraged, due to the interfering effects of the SAA, but in consultation with our Contact Scientist and Program Coordinator (Dr. Hugues Sana, Tony Roman), we were told this is likely to be possible, contingent on the exact position of our chosen target. ------ Calibration Justification ------- Our SN, which is optically bright, will have ground-based astrometry with respect to HST guide stars accurate to better than 0.2''. Using the STIS Acquisition ETC we find acquisition times of less than 1 min for all epochs, for the 0.2'' slit. Previously, we have successfully acquired SNe with STIS in this manner. --------- Additional Comments ---------- This is a ToO proposal. We will update our phase 2 with the supernova coordinates as they become available. In order to make sure there are no bright objects in the target vicinity and to estimate the target UV flux, we will obtain rapid-response Swift/UVOT observations, as we have done in the past for this program. HOT STARS 12 Regular false false false false false SUPPORTED EXT-STAR SUPERNOVA J2000 STIS/NUV-MAMA Spectroscopic No No G230L 2376 STIS/CCD Spectroscopic No No G430L 4300 STIS/CCD Spectroscopic No No G750L 7751 POS-TARG DITHER 0.275 LINE false false 3 90.0 STIS-ALONG-SLIT 1 false POS-TARG DITHER 0.275 LINE false false 2 90.0 STIS-ALONG-SLIT 2 false Timing link suitability includes constraints ([02 After 01 by 6.0 to 8.0 days]) The scheduling data was generated by CASM 23.0. CASM was run in Phase II mode. 53.5 /solaris/user1/aroman/work/OP-cache/13797-v01.xml 1428144925000 292.2058492404784 (Tic-Visit :proposal-id 13797 :visit-id "01" :proposal-version -1 :trans-version "20150128" :date "01-Apr-2015 02:09:19.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 6 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 669712 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13797 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13797 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2877 :al-overhead-at-end 198 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 198 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 198 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 0 :internal-dur-at-end 113 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "01" :orbit-number 5 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 85 :internal-dur-at-end 132 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "01" :orbit-number 6 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 0 :internal-dur-at-end 660 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) true 6 0 Initial ToO visit Our SN. though UV-faint, will be optically bright. Using the STIS Acquisition ETC and the spectrum of PTF12gzk obtained in Cycle 20, we find that a 2s exposure yields a S/N > 100. Our SN. though UV-faint, will be optically bright. Using the STIS Acquisition ETC and the spectrum of PTF12gzk obtained in Cycle 20, we find that a 2s exposure yields a S/N > 100. Timing link suitability includes constraints ([02 After 01 by 6.0 to 8.0 days] [03 After 02 by 6.0 to 8.0 days]) The scheduling data was generated by CASM 23.0. CASM was run in Phase II mode. 53.5 /solaris/user1/aroman/work/OP-cache/13797-v02.xml 1428740333000 285.174357825525 (Tic-Visit :proposal-id 13797 :visit-id "02" :proposal-version -1 :trans-version "20150128" :date "01-Apr-2015 02:23:29.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 600128 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13797 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13797 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2877 :al-overhead-at-end 198 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 198 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 198 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 0 :internal-dur-at-end 113 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "02" :orbit-number 5 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 0 :internal-dur-at-end 660 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) true 5 0 2nd ToO visit Our SN. though UV-faint, will be optically bright. Using the STIS Acquisition ETC and the spectrum of PTF12gzk obtained in Cycle 20, we find that a 2s exposure yields a S/N > 100. Our SN. though UV-faint, will be optically bright. Using the STIS Acquisition ETC and the spectrum of PTF12gzk obtained in Cycle 20, we find that a 2s exposure yields a S/N > 100. Timing link suitability includes constraints ([03 After 02 by 6.0 to 8.0 days]) The scheduling data was generated by CASM 23.0. CASM was run in Phase II mode. 53.5 /solaris/user1/aroman/work/OP-cache/13797-v03.xml (Tic-Visit :proposal-id 13797 :visit-id "03" :proposal-version -1 :trans-version "20150128" :date "01-Apr-2015 02:22:51.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 600128 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13797 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13797 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2877 :al-overhead-at-end 198 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 198 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 198 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "03" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 0 :internal-dur-at-end 113 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13797 :visit-id "03" :orbit-number 5 :pcs-time 222 :si-vis-utilization 2988 :al-overhead-at-end 0 :internal-dur-at-end 601 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3210.0 :pcs-gap 0 ) true 5 0 3rd ToO visit Our SN. though UV-faint, will be optically bright. Using the STIS Acquisition ETC and the spectrum of PTF12gzk obtained in Cycle 20, we find that a 2s exposure yields a S/N > 100. Our SN. though UV-faint, will be optically bright. Using the STIS Acquisition ETC and the spectrum of PTF12gzk obtained in Cycle 20, we find that a 2s exposure yields a S/N > 100.