18206( 4) - 04-Feb-2026 15:18:21 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18206 Version: 4 Check-in Time: 04-Feb-2026 15:18:21 STScI Edit Number: 0 Title Narrowband Imaging of NGC 3372 ------------------------------------------------------------------------------------ Type Cycle GO/DD 32 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Christopher Britt Space Telescope Science Institute Y CoI: Max Mutchler Space Telescope Science Institute Y CoI: John Maple Space Telescope Science Institute Y CoI: Joseph DePasquale Space Telescope Science Institute N CoI: Alyssa Pagan Space Telescope Science Institute N CoI: Varun Bajaj Space Telescope Science Institute N CoI: Christine Pulliam Space Telescope Science Institute N CoI: Ray Villard Space Telescope Science Institute N CoI: Miranda Brugman Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract We propose to image dense pillars within the star forming nebula NGC 3372. Imaging in F502N, F657N, and F673N will identify variations of density and ionization in the atomic gas surrounding this active area of star formation and identify any protostellar outflows emerging from the pillar. Broadband imaging in F475W and F814W will enable accurate measurement of stellar colors in the field. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will obtain high signal-to-noise imaging of Carina nebula Cats Head in narrowband filters F502N, F657N, F673N, as well as broadband filters F475W and F814W. The B and I filters will provide a balanced color profile to the stars in the image, while the [O III], Halpha+[N II], and [SII] narrowband filters will highlight regions of differing density and ionization state through the nebula. We propose a single WFC3 pointing which will adequately cover the entire object at any Position Angle. A likely PA is shown in Figure 2, with ACS parallels that catch a second interesting region. In the event of needing to retake a failed visit, as an exact match of the PA is not possible in Reduced Gyro Mode, we will crop and zero-pad the image background as necessary so that no part of the image is missing one or more colors. Dither strategies are selected to minimize the impact of variation of the PA. We will also employ a dither pattern which fills the chip gaps and enables cosmic ray rejection. We calculate exposure times from archival observations of this object with ACS. Using line ratios from the nearby Mystic Mountain with the same filter set within the ETC, we estimate that we can achieve the high signal-to-noise needed for imaging with 6 orbits, with approximately 1 for F657N, 2 for F502N, and 3 for F673N. The broadband filter exposures can be placed as short bookends to the narrowband observations. The ACS parallel observations on the nearby interesting region will be in F658N. ------------------------------------------------------------------------------------ 18206( 4) - 04-Feb-2026 15:18:21 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-3372 ISM, HERBIG-HARO OBJECT RA=10H46M0.8522S, J2000 V = 18 +/- 8 DEC=-60D06'28.76" Reference Frame: ICRS Extended: YES Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. SIMBAD listed proper motion for this target. When retrieving targets with PM from SIMBAD, APT requests the coordinates be calculated with an epoch of the year 2000. Do not modify this epoch. Always review coordinates using the Target Confirmation tool, which graphically displays the PM. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -8.761952298325078E-4 0.00217 3.8E-4 ------------------------------------------------------------------------------------------------------------------------------------ 18206( 4) - 04-Feb-2026 15:18:21 - [ 3] Visit: 11 Visit Requirements: ORIENT 320D TO 330 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F475W FLASH=15 1 90 S (90 POS TARG -0.2, -30; PAR S ER S) 6 WITH 1-5 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F502N FLASH=15 1 600 S (600 POS TARG -0.2, -30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F657N FLASH=15 1 300 S (300 POS TARG -0.2, -30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F673N FLASH=15 1 900 S (900 POS TARG -0.2, -30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F814W FLASH=15 1 60 S (60 POS TARG -0.2, -30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 6 ANY ACS/WFC ACCUM WFCENTER F658N 2 1000 S (2000 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC-3372 1 WFC3/UVI ACCUM UVIS-CEN F475W none none none none 1 N/A S TER NGC-3372 2 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-3372 3 WFC3/UVI ACCUM UVIS-CEN F657N none none none none 1 N/A S TER NGC-3372 4 WFC3/UVI ACCUM UVIS-CEN F673N none none none none 1 N/A S TER NGC-3372 5 WFC3/UVI ACCUM UVIS-CEN F814W none none none none 1 N/A S TER ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 1 none 1 N/A ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 2 none 1 N/A 18206( 4) - 04-Feb-2026 15:18:21 - [ 4] Visit: 12 Visit Requirements: SAME ORIENT AS 11 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F475W FLASH=15 1 90 S (90 POS TARG -0.2, -30; PAR S ER S) 6 WITH 1-5 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F502N FLASH=15 1 600 S (600 POS TARG -0.2, -30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F657N FLASH=15 1 300 S (300 POS TARG -0.2, -30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F673N FLASH=15 1 900 S (900 POS TARG -0.2, -30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F814W FLASH=15 1 60 S (60 POS TARG -0.2, -30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 6 ANY ACS/WFC ACCUM WFCENTER F658N 2 1000 S (2000 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC-3372 1 WFC3/UVI ACCUM UVIS-CEN F475W none none none none 1 N/A S TER NGC-3372 2 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-3372 3 WFC3/UVI ACCUM UVIS-CEN F657N none none none none 1 N/A S TER NGC-3372 4 WFC3/UVI ACCUM UVIS-CEN F673N none none none none 1 N/A S TER NGC-3372 5 WFC3/UVI ACCUM UVIS-CEN F814W none none none none 1 N/A S TER ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 1 none 1 N/A ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 2 none 1 N/A 18206( 4) - 04-Feb-2026 15:18:21 - [ 5] Visit: 13 Visit Requirements: ORIENT 337D TO 339 D; BEFORE 31-MAR-2026:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F475W FLASH=15 1 90 S (90 PAR 6 WITH 1-5 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F502N FLASH=15 1 600 S (600 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F657N FLASH=15 1 300 S (300 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F673N FLASH=15 1 900 S (900 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F814W FLASH=15 1 60 S (60 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 6 ANY ACS/WFC ACCUM WFCENTER F658N 2 1000 S (2000 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC-3372 1 WFC3/UVI ACCUM UVIS-CEN F475W none none none none 1 N/A S TER NGC-3372 2 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-3372 3 WFC3/UVI ACCUM UVIS-CEN F657N none none none none 1 N/A S TER NGC-3372 4 WFC3/UVI ACCUM UVIS-CEN F673N none none none none 1 N/A S TER NGC-3372 5 WFC3/UVI ACCUM UVIS-CEN F814W none none none none 1 N/A S TER ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 1 none 1 N/A ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 2 none 1 N/A 18206( 4) - 04-Feb-2026 15:18:21 - [ 6] Visit: 14 Visit Requirements: SAME ORIENT AS 11 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F475W FLASH=15 1 90 S (90 PAR 6 WITH 1-5 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F502N FLASH=15 1 600 S (600 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F657N FLASH=15 1 300 S (300 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F673N FLASH=15 1 900 S (900 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F814W FLASH=15 1 60 S (60 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 6 ANY ACS/WFC ACCUM WFCENTER F658N 2 1000 S (2000 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC-3372 1 WFC3/UVI ACCUM UVIS-CEN F475W none none none none 1 N/A S TER NGC-3372 2 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-3372 3 WFC3/UVI ACCUM UVIS-CEN F657N none none none none 1 N/A S TER NGC-3372 4 WFC3/UVI ACCUM UVIS-CEN F673N none none none none 1 N/A S TER NGC-3372 5 WFC3/UVI ACCUM UVIS-CEN F814W none none none none 1 N/A S TER ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 1 none 1 N/A ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 2 none 1 N/A 18206( 4) - 04-Feb-2026 15:18:21 - [ 7] Visit: 15 Visit Requirements: SAME ORIENT AS 11 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F475W FLASH=15 1 90 S (90 POS TARG 0.2, 30; PAR 6 S ER S) WITH 1-5 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F502N FLASH=15 1 600 S (600 POS TARG 0.2, 30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F657N FLASH=15 1 300 S (300 POS TARG 0.2, 30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F673N FLASH=15 1 900 S (900 POS TARG 0.2, 30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F814W FLASH=15 1 60 S (60 POS TARG 0.2, 30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 6 ANY ACS/WFC ACCUM WFCENTER F658N 2 1000 S (2000 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC-3372 1 WFC3/UVI ACCUM UVIS-CEN F475W none none none none 1 N/A S TER NGC-3372 2 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-3372 3 WFC3/UVI ACCUM UVIS-CEN F657N none none none none 1 N/A S TER NGC-3372 4 WFC3/UVI ACCUM UVIS-CEN F673N none none none none 1 N/A S TER NGC-3372 5 WFC3/UVI ACCUM UVIS-CEN F814W none none none none 1 N/A S TER ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 1 none 1 N/A ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 2 none 1 N/A 18206( 4) - 04-Feb-2026 15:18:21 - [ 8] Visit: 16 Visit Requirements: SAME ORIENT AS 11 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F475W FLASH=15 1 90 S (90 POS TARG 0.2, 30; PAR 6 S ER S) WITH 1-5 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F502N FLASH=15 1 600 S (600 POS TARG 0.2, 30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F657N FLASH=15 1 300 S (300 POS TARG 0.2, 30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F673N FLASH=15 1 900 S (900 POS TARG 0.2, 30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC-3372 WFC3/UVI ACCUM UVIS-CENT F814W FLASH=15 1 60 S (60 POS TARG 0.2, 30 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 6 ANY ACS/WFC ACCUM WFCENTER F658N 2 1000 S (2000 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC-3372 1 WFC3/UVI ACCUM UVIS-CEN F475W none none none none 1 N/A S TER NGC-3372 2 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-3372 3 WFC3/UVI ACCUM UVIS-CEN F657N none none none none 1 N/A S TER NGC-3372 4 WFC3/UVI ACCUM UVIS-CEN F673N none none none none 1 N/A S TER NGC-3372 5 WFC3/UVI ACCUM UVIS-CEN F814W none none none none 1 N/A S TER ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 1 none 1 N/A ANY 6 ACS/WFC ACCUM WFCENTER F658N none none 2 none 1 N/A 18206( 4) - 04-Feb-2026 15:18:21 - [ 9] Summary Form for Proposal 18206 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER, WFCENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=15 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 31-MAR-2026:00:00:00, ORIENT 320D TO 330 D, ORIENT 337D TO 339 D, PAR 6 WITH 1-5, POS TARG -0.2, -30, POS TARG 0.2, 30, SAME ORIENT AS 11 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F475W, F502N, F657N, F658N, F673N, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names ANY, NGC-3372 ------------------------------------------------------------------------------------------------------------------------------------