Second submission. Revised two phrases during a second proofread for extra caution. 331998966 Assigned ID: 5303 ----- Attempting Submission 1 (Tue Mar 26 02:20:08 GMT 2024) ----- HST Phase I Proposal 5303 successfully submitted. Receipt: # 5303-1 ----- Attempting Submission 2 (Tue Mar 26 09:33:58 GMT 2024) ----- ORBIT PLANNER SERVER INTERNAL ERROR Revised Phase II file submission to be sufficiently in compliance with suggestions from TTRB. -788513213 ----- Attempting Submission 1 (Tue Aug 13 22:28:42 GMT 2024) ----- HST Phase II Proposal 17789 successfully submitted. Receipt: # 17789-1 ----- Attempting Submission 2 (Fri Nov 08 18:46:49 GMT 2024) ----- I ran the tool and confirmed the target is correctly identified in the finder charts. The J2000 coordinates and associated proper motions are correct as well. The atmospheres of white dwarfs that are accreting a tidally disrupted planetesimal are powerful tools for deriving the bulk chemical composition of exoplanets. Ultraviolet (UV) spectroscopy is necessary to extract the most accurate abundances of these polluted white dwarfs, due to the high temperatures of most white dwarfs and the higher density of metal lines in the UV compared to the optical. Recent studies have discovered several metal-rich white dwarfs that show transits from tidally disrupted debris, but only two such systems have been extensively studied in the UV. We propose near-ultraviolet spectroscopy of ZTF J0328-1219, a newly discovered remnant planetary system that shows persistent transits from a planetary debris disk that repeat every 10 hours. Our proposal is designed to obtain the near-UV (NUV) spectra required to most accurately derive the abundances of the disrupted rocky material in orbit around the white dwarf and create a time-tagged NUV light curve to constrain the possible wavelength dependence of the transit depths. Our observations will put ZTF J0328-1219 into the broader context of other transiting debris systems, marking a crucial step in understanding the relationship between the orbital periods and eccentricities and observed properties. The goal of this HST program is to obtain time-resolved STIS near-ultraviolet spectroscopy of the white dwarf ZTFJ0328-1219 to (1) detect the photospheric metal absorption lines in this wavelength range and (2) to probe for color-dependence of the transit depth. The orbital period of the debris is 9.94h. The observations will be done using the G230L grating, TIME-TAG mode, and the 52x0.5 aperture. The target acquisition will be performed via a CCD image taken with the FP28x50LP broad-band filter. We used a Teff=7630K blackbody scaled to SDSS g=16.7 for the acquisition ETC run. For the ETC simulation of the STIS TIME-TAG spectrophotometry, we used a white dwarf model spectrum computed with the parameters from Table 6 of Vanderbosch et al. 2021 (ApJ 917, 41), i.e. Teff=7630K, log g=8.245, log(C/He)=-9.55, and we scaled all other elements to Bulk Earth abundances. As per our Phase I proposal, the observations have to be carried in a single 5-orbit visit, which will cover nearly a full orbital cycle of the debris. Guidry is an expert in using large time-domain surveys to discover and characterize white dwarf variability, both in the optical and mid-infrared. Guidry has been involved in the discovery of every transiting debris system following WD1145+017 and ZTF J0139+5245, the second such system. Hermes is an expert on white dwarf variability, and has been involved in the discovery of all new transiting debris systems since WD1145+017. Hermes is also an expert in the analysis of analyzing time-tagged STIS data. Hermes and Guidry have guaranteed access to the 1.8-meter Perkins Telescope in Flagstaff, AZ, which is 100% owned and operated by Boston University. This will allow maximal scheduling flexibility to guarantee ground- based, optical, time-series photometry of our target regardless of when it is scheduled to be observed by HST. Vanderbosch is an expert on white dwarf variability, and has been involved in the discovery of all new transiting debris systems since WD1145+017, excluding WD1054-226. He has guaranteed access to optical resources as a postdoctoral fellow at Caltech. Gaensicke has been PI of 20 HST programs, carrying out ultraviolet spectroscopy of white dwarfs, including large, medium, small GO programs and several snapshot programs. He has in-depth experience in the analysis and interpretation of the observations of accreting white dwarfs, both in binary systems, and evolved planetary systems. He will assist in implementing the observations and their analysis. Exoplanets and Exoplanet Formation Stellar Physics and Stellar Types 6 false false true false false false false false SUPPORTED STAR DC NO J2000 J2000 Gaia G=16.6, GALEX NUV=18.91, SDSS g=16.7 STIS/NUV-MAMA Spectroscopic No No G230L 2376 1731014085470 The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. /Users/astrojoe/Research/Observing_Proposals/HST/HST_Cycle32_ZTFJ0328/PhaseII/OP-cache/HST_Cycle32_GO17789_Revised-v01.xml (Tic-Visit :proposal-id 17789 :visit-id "01" :proposal-version -1 :trans-version "20240627" :date "07-Nov-2024 16:14:45.0" :trans-errors '(:WARNINGS 0 :ERRORS 1 :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 2105232 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17789 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17789 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2533 :al-overhead-at-end 0 :internal-dur-at-end 178 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2913 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17789 :visit-id "01" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2533 :al-overhead-at-end 0 :internal-dur-at-end 339 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2913 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17789 :visit-id "01" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2533 :al-overhead-at-end 0 :internal-dur-at-end 339 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2913 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17789 :visit-id "01" :orbit-number 4 :pcs-time 380 :si-vis-utilization 2533 :al-overhead-at-end 0 :internal-dur-at-end 339 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2913 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17789 :visit-id "01" :orbit-number 5 :pcs-time 380 :si-vis-utilization 2533 :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 2913 :pcs-gap 0 ) true 5 0 We used a T=7630K blackbody scaled to SDSS g=16.7 for the acquisition ETC run. We computed a white dwarf model spectrum with the parameters in Table 6 of Vanderbosch et al. 2021 (ApJ 917, 41) as input for the ETC calculation.