17992( 3) - 15-Jan-2026 11:57:51 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17992 Version: 3 Check-in Time: 15-Jan-2026 11:57:51 STScI Edit Number: 0 Title Monitoring for Collisions in the Beta Pictoris Debris Disk to Enable JWST Follow-Up Spectroscopy ------------------------------------------------------------------------------------ Type Cycle GO 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Kevin Wagner University of Arizona Y CoI: Prof. Daniel Apai University of Arizona N CoI: Arin Avsar University of Arizona N ------------------------------------------------------------------------------------ Abstract Debris disks are readily detectable tracers of planetesimal collisions within young planetary systems; however, few collisions have been observed in detail. Among the earliest and most noteworthy JWST results of debris disks was evidence of major (Ceres-mass) collisions having occurred over the past century within Beta Pictoris. This indicates that the chance to observe a major planetesimal collision shortly after it occurrs may be non-neglegible over decade timescales, and the chance of observing lower-mass collisions, which should be more frequent but visible only for months to years, may be substantial. Observing such a collision shortly after it occurs and tracking the evolution of its dust cloud would open a major window into the dust produced via planetesimal collisions -- including measurements of planetesimal composition, grain-size constraints, collisional frequency estimates, and dust production rates, to name a few possibilities. Additionally, recent time-differential HST/STIS imaging has demonstrated that multi-epoch observations have the capability to push orders of magnitude lower in collisional mass detection limits compared to single-epoch imaging. Here, we propose to build off of 27 years of HST/STIS observations of the Beta Pictoris system in order to monitor for collisions over the next three cycles. Regular re-visits allow detecting collisions shortly after they occur, enabling follow up proposals for JWST to place unique constraints on the resulting dust. In the absence of such a detection, we will continue to place meaningful constraints on the frequency of collisions and the distribution of major planetessimals within the Beta Pictoris system. ------------------------------------------------------------------------------------ Observations Description ------------------------ The proposed observations aim to obtain STIS coronagraphic images of the Beta Pictoris debris disk. The primary goal is to compare the disk surface brightness distribution to prior STIS observations of the same disk, to identify or constrain changes in the disk structure. WThis data set will allow PSF subtraction both through roll (self)subtraction and through PSF subtraction, thus allowing two alternate reduction methods. The combination of the data sets will provide an optimal spatial coverage and can correct for the field lost due to wedge obscuration and diffraction spike contamination. Based on the comparison of the reduced 1997 and 2012 data and a set of PSF 17992( 3) - 15-Jan-2026 11:57:51 - [ 2] stars from other programs we identified that the following strategy provides the best quality data and best comparison to the earlier data sets: We will observe the two targets using three single-orbit visits (01, 02, 03) that are linked both in time and orientation angles. The three visits must be scheduled "back-to-back" in sequential visibility periods, each uninterrupted by Earth occultation -- hence the AFTER scheduling requirements of 0.5 to 1.5 orbit (start-to-start) times on Visits 02 and 03. In Visit 01 we observe our science target (Beta Pic). In Visit 02 we will observe our PSF calibration target (Alpha Pic). The Alpha Pic visit (02) MUST be scheduled in time in between Visits 01 and 03. In Visit 03 we again observe Beta Pic, but at an orientation angle differing by 10-20 deg from the absolute orientation specified for Visit 01. We begin each Visit with an on-board autonomous coronagraphic target acquisition. Target acquisition exposure times were chosen to provide SNR ~ 100 in the central pixel of the target acq images. In all cases we use the F25ND5 filter due to the brightness of our target stars. First orbit: We will observe Beta Pic at the WedgeB1.0 position. We will obtain a series of long and short exposures to enable high dynamic range of the bright (inner) and faint (outer) regions. Absolute orientation ensures the edge-on disk is not overlapping the wedge or difraction spikes. Second Orbit: Carry out the same observing sequence as in Orbit 1 on the PSF star Alpha Pictoris. This star is slightly brighter, so exposures are shorter to avoid saturation. In this visit we observe our PSF template calibration star. In order to minimize variations in PSF structure from thermal driven changes in OTA wavefront errors, we constrain the orientation of this calibration target which is nearby in the sky to our science target (similar spacecraft attitude and sun angle) to be as close as possible to the orientations of Visits 1 and 3. Third Orbit: Repeat the observations of Beta Pic (1st orbit) but at a different spacecraft orientation. EXPOSURE TIMES: Individual coronagraphic exposure times (Ex. Time / # CR Splits) have been carefully chosen at all wedge positions based upon prior coronagraphic imaging so as not to saturate at the smallest IWA for each wedge position while also providing > appx 70% full well depth. NOTE TO OUR PC: Please do *NOT* allow "automatic" adjustment of any exposure times in our coronagraphic exposures to fill any (small) "dead time" in the orbits ORIENTATIONS: The observations are sensitive to the roll angles: the right angles will ensure that the disk is optimally placed between the wedges and the diffraction spikes at both orientations and minimize the spatial coverage lost due to obscuration. 17992( 3) - 15-Jan-2026 11:57:51 - [ 3] DISK AND SPACECRAFT ORIENTATIONS: The "northern" semi-major axis of the nearly-edge on Beta Pic disk is at a celestial position angle of appx 30.8 deg. (The inner disk itself is warped and PAs varying by a few degrees appear in the literature, depending upon how and at what distances measures have been made. For our observation planning we adopt 30.8 deg). If a suitable GS pair cannot be found to enable this geometry, we would later suggest possible specific alternates depending upon schedualbility with more restrictive differential roll ranges with trades in science return. The three orbits must be executed back-to-back to minimize the changes in the instrumental PSF and the spacecraft/instrument state. ------------------------------------------------------------------------------------ 17992( 3) - 15-Jan-2026 11:57:51 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 BETA-PIC STAR, A4-A9 V-IV RA=05H47M17.0877S +/- 0.1", J2000 V = 3.86 B=4.03 DEC=-51D03'59.45" +/- 0.1" Reference Frame: ICRS Comments: Beta Pictoris, debris disk: semi-major axis P.A.: +30.8 degree (E of N) A6V Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 4.93302394363132E-4 0.0831 0.05144 ------------------------------------------------------------------------------------------------------------------------------------ 2 ALPHA-PIC CALIBRATION, POINT RA=06H48M11.4600S +/- 0.1", J2000 V = 3.30 B=3.48 SPREAD FUNCTION DEC=-61D56'29.00" +/- 0.1" Reference Frame: ICRS Comments: PSF calibrator for Beta Pictoris Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -0.009364169072781236 0.24297 0.03378 ------------------------------------------------------------------------------------------------------------------------------------ 17992( 3) - 15-Jan-2026 11:57:51 - [ 5] Visit: 01 Visit Requirements: PCS MODE FINE; ORIENT 354D TO 360 D; ORIENT 157D TO 177 D On Hold Comments: Additional Comments: Timing: Must be executed in sequential orbit immediately prior to Visit 02 with only intervening inter-visit Earth occultation. Orientation: Absolute Orientation range set to place disk away from difraction spikes and WedgeA. 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 BETA-PIC STIS/CCD ACQ F25ND5 MIRROR 1 3.1 S (3.1 GS ACQ SCENARIO BASE1O3 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=8, 1 9.6 S (9.6 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=8, 1 9.6 S (9.6 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=427, CR-SPLIT=4, 1 200 S (200 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=427, CR-SPLIT=8, 1 24 S (24 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=427, CR-SPLIT=8, 1 24 S (24 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=4, GAIN=4, 1 210 S (210 SIZEAXIS2=427 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=8, GAIN=4, 1 24 S (24 SIZEAXIS2=427 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=3, GAIN=4, 1 8 S (8 S) SIZEAXIS2=427 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETA-PIC 1 STIS/CCD ACQ F25ND5 MIRROR none none none none 1 N/A BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 BETA-PIC 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 7] 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 8] 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 9] Visit: 02 Visit Requirements: PCS MODE FINE; ORIENT -6.1D TO 6.1D FROM 01; AFTER 01 BY .5 Orbits TO 1.5 Orbits On Hold Comments: Additional Comments: Timing: Must be executed in sequential orbit immediately after Visit 01 with only intervening inter-visit Earth occultation. Orientation: set to be as close as possible to Visit 1 and/or Visit 2 to minimize Sun-spacecraft angle differences. 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 ALPHA-PIC STIS/CCD ACQ F25ND5 MIRROR 1 1.9 S (1.9 GS ACQ SCENARIO BASE1O3 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=8, 1 5.6 S (5.6 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=8, 1 5.6 S (5.6 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=3, 1 2.1 S (2.1 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=3, 1 2.1 S (2.1 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=3, 1 2.1 S (2.1 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=427, CR-SPLIT=4, 1 144 S (144 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=427, CR-SPLIT=8, 1 15.2 S GAIN=4 (15.2 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=427, CR-SPLIT=8, 1 15.2 S GAIN=4 (15.2 S) ------------------------------------------------------------------------------------------------------------------------------------ 10 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=4, GAIN=4, 1 144 S (144 SIZEAXIS2=427 S) ------------------------------------------------------------------------------------------------------------------------------------ 11 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=8, GAIN=4, 1 15.2 S SIZEAXIS2=427 (15.2 S) ------------------------------------------------------------------------------------------------------------------------------------ 12 ALPHA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=3, GAIN=4, 1 5.7 S (5.7 SIZEAXIS2=427 S) ------------------------------------------------------------------------------------------------------------------------------------ 17992( 3) - 15-Jan-2026 11:57:51 - [ 10] 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 | ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ ALPHA-PIC 1 STIS/CCD ACQ F25ND5 MIRROR none none none none 1 N/A ALPHA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 ALPHA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 ALPHA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 ALPHA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 ALPHA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 ALPHA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 ALPHA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 ALPHA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 ALPHA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 ALPHA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 ALPHA-PIC 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 11] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ALPHA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 ALPHA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 ALPHA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 ALPHA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 ALPHA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 ALPHA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 ALPHA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 ALPHA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 ALPHA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 ALPHA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 12] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ALPHA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 ALPHA-PIC 10 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 10 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 10 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 10 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 ALPHA-PIC 11 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 11 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 11 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 ALPHA-PIC 11 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 ALPHA-PIC 11 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 ALPHA-PIC 11 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 ALPHA-PIC 11 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 ALPHA-PIC 11 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 ALPHA-PIC 12 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 ALPHA-PIC 12 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 ALPHA-PIC 12 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 13] Visit: 03 Visit Requirements: PCS MODE FINE; ORIENT 6.9D TO 20D FROM 01; AFTER 02 BY 0.5 Orbits TO 1.5 Orbits On Hold Comments: Additional Comments: Timing: Must be executed in sequential orbit immediately after Visit 03 with only intervening inter-visit Earth occultation. Orientation: set relative to Visit01 while keeping disk between difraction spikes and WedgeA. 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 BETA-PIC STIS/CCD ACQ F25ND5 MIRROR 1 3.1 S (3.1 GS ACQ SCENARIO BASE1O3 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=7, 1 8.4 S (8.4 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=7, 1 8.4 S (8.4 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=137, CR-SPLIT=2, 1 2.4 S (2.4 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=427, CR-SPLIT=4, 1 210 S (210 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=427, CR-SPLIT=8, 1 24 S (24 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR SIZEAXIS2=427, CR-SPLIT=8, 1 24 S (24 GAIN=4 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=4, GAIN=4, 1 200 S (200 SIZEAXIS2=427 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=8, GAIN=4, 1 24 S (24 SIZEAXIS2=427 S) ------------------------------------------------------------------------------------------------------------------------------------ 10 BETA-PIC STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=3, GAIN=4, 1 8 S (8 S) SIZEAXIS2=427 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETA-PIC 1 STIS/CCD ACQ F25ND5 MIRROR none none none none 1 N/A BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 14] 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 BETA-PIC 2 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 BETA-PIC 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 5 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 15] 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 6 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 7 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 8 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 BETA-PIC 9 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 BETA-PIC 10 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 16] 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 | ------------------------------------------------------------------------------------------------------------------------------------ BETA-PIC 10 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 BETA-PIC 10 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 17992( 3) - 15-Jan-2026 11:57:51 - [ 17] Summary Form for Proposal 17992 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F25ND5, WEDGEA1.0 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2, CR-SPLIT=3, CR-SPLIT=4, CR-SPLIT=7, CR-SPLIT=8, GAIN=4, SIZEAXIS2=137, SIZEAXIS2=427 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY .5 Orbits TO 1.5 Orbits, AFTER 02 BY 0.5 Orbits TO 1.5 Orbits, GS ACQ SCENARIO BASE1O3, ORIENT -6.1D TO 6.1D FROM 01, ORIENT 157D TO 177 D, ORIENT 354D TO 360 D, ORIENT 6.9D TO 20D FROM 01, PCS MODE FINE ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names ALPHA-PIC, BETA-PIC ------------------------------------------------------------------------------------------------------------------------------------