0 1 orbit visit for E0102 imaging with ACS-WFC through F475W with 3-pt line dither to fill interchip gap and remove CRs. The Orbit and Visit Planners appear to execute as intended. The 2250 secs actual total exptime seems low, so please advise if that can be improved. APT states that 1G mode is the default, but is this proper motion program a candidate for 2G or 3G, since spatial resolution is very important? Thanks! -JM -354818038 ----- Attempting Submission 1 (Mon Jan 27 01:33:54 GMT 2025) ----- ACS WFC [O III] Imaging of the Iconic Young SNR 1E0102.2-7219 in the SMC We propose to obtain a final Advanced Camera for Surveys (ACS) Wide-Field Channel (WFC) image in the light of [O III]4959,5007 emission of the young, oxygen-rich supernova remnant 1E0102.2-7219 (E0102) in the Small Magellanic Cloud (SMC). When combined with prior ACS/WFC images from 2003 and 2013, this will establish a 20+ year baseline of multi-epoch ACS imaging for measuring proper motions of the pristine supernova ejecta and detecting temporal changes in flux and velocity. E0102 has low line-of-sight extinction, represents the core-collapse explosion of a massive star in a low-metallicity environment akin to the high redshift universe, and has copious supporting data from extensive observations across the entire electromagnetic spectrum. This investigation of E0102 requires <0.1 arcsec spatial resolution in order to measure precise proper motions of the ejecta and resolve important physical scales at the distance of the SMC. Even with the multi-decade time baseline, the ejecta motions to be measured are still only one to several 50 mas ACS pixels in magnitude. We thus emphasize the importance for very precise image registration of obtaining a final ACS image epoch so that images obtained through the same optical system -- with the same image scale and geometric distortions -- can be compared. As demonstrated for Cas A using WFPC2, broadband filter imaging is an effective way to reveal structure of enriched ejecta in specific elemental species in young SNRs like E0102.2-7219 (E0102) when the emission-line spectrum is dominated by a few strong features, especially the [O III]4959,5007 doublet. The ACS/WFC F475W filter covering ~400-540 nm captures the total velocity range of the [O III]-emitting ejecta in E0102 without significant contamination by stars. The ACS imaging strategy will follow standard image acquisition and dithering techniques that have been successful on prior programs. There are no special requirements for roll constraints since we expect numerous stars to be available in all image sets for alignment purposes. We use only a single normal orbit in the APT tool for estimating scheduling feasibility, with many observing windows during the remainder of Cycle 32 and beyond. We will obtain three 750 sec WFC images in a single orbit through the F475W filter using a 3-point line dither pattern to fill the interchip gap. Standard pipeline processing for removing cosmic rays and instrumental artifacts suffice for preparing the new image for comparison with the two prior F475W epochs (2003, 2013), as well as the 1995 WFPC2 Planetary Camera image through F502N. Typical [O III]4959,5007 surface brightnesses range from ~10**-14 ergs/s/cm2/arcsec2 in knots and <10**-16 ergs/s/cm2/arcsec2 in fainter filaments. A continuum image through the F550M filter was obtained during HST PID 12001 (2003) and can be aligned to the PID 12858 (2013) and new F475W images to help distinguish emission knots from stars as necessary. There are no critical timing or ORIENT constraints associated with this program. Dr. Jon Morse is an expert on SNRs and has been conducting research on E0102 and similar objects for several decades. He was PI of HST program 6052 that originally imaged E0102 and N132D with HST, and was Co-I on the program to obtain HST/FOS UV-optical spectroscopy, including running the large grid of shock models used for determining physical conditions and abundances in the SNR ejecta and surrounding shocked ISM clouds. He now has a research position at Caltech where he will perform the analysis of the proposed observations. Dr. Nathan Smith has also observed and analyzed SN and SNR data for several decades. His involvement with a large number of SN and LBV observing campaigns provides important expertise for interpreting the measurements of the SNR age and origin. Drs. Morse and Smith have worked together for over 25 years on various projects that involve analysis of nebular emission targets and time domain observations for measuring proper motions. They will involve students and postdocs in this research campaign, have modern computer and data storage capabilities, and have access to ground-based facilities for follow-up observations. Stellar Physics and Stellar Types Stellar Populations and the Interstellar Medium 6 false false false false true false false false false false SUPPORTED ISM SNR YES This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 1.5e-14 ACS/WFC Imaging No No F475W POS-TARG DITHER 3.034 LINE false false 3 85.29 ACS-WFC-DITHER-LINE 1 false The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. Single orbit of F475W imaging of E0102 with LINE dithering to fill interchip gap and reject CR's. 1745443401000 195.0432708347223 (Tic-Visit :proposal-id 17917 :visit-id "01" :proposal-version -1 :trans-version "20241217" :date "26-Jan-2025 17:26:24.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 852672 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17917 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17917 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2794 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3184 :pcs-gap 0 ) true 1 0 Single orbit of F475W imaging of E0102 with LINE dithering to fill interchip gap and reject CR's. 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