Version 1: test submission Version 2: full submission Version 3: added seq and non-int Version 4: small corrections Version 5: more small corrections 326236828 Assigned ID: 5058 ----- Attempting Submission 1 (Fri Mar 22 20:32:45 GMT 2024) ----- HST Phase I Proposal 5058 successfully submitted. Receipt: # 5058-1 ----- Attempting Submission 2 (Tue Mar 26 05:45:32 GMT 2024) ----- HST Phase I Proposal 5058 successfully submitted. Receipt: # 5058-2 ----- Attempting Submission 3 (Tue Mar 26 05:53:35 GMT 2024) ----- HST Phase I Proposal 5058 successfully submitted. Receipt: # 5058-3 ----- Attempting Submission 4 (Tue Mar 26 17:59:56 GMT 2024) ----- HST Phase I Proposal 5058 successfully submitted. Receipt: # 5058-4 ----- Attempting Submission 5 (Tue Mar 26 21:24:23 GMT 2024) ----- ORBITAL VISIBILITY OVERRUN Visits (01, 02) have a relative orient link whose targets (17741-01-BETA-PIC, 17741-02-ALPHA-PIC) are separated by more than 1 degree. This may make it impossible to get guide stars. ORBITAL VISIBILITY OVERRUN Visits (01, 02) have a relative orient link whose targets (17741-01-BETA-PIC, 17741-02-ALPHA-PIC) are separated by more than 1 degree. This may make it impossible to get guide stars. ORBITAL VISIBILITY OVERRUN Visits (01, 02) have a relative orient link whose targets (17741-01-BETA-PIC, 17741-02-ALPHA-PIC) are separated by more than 1 degree. This may make it impossible to get guide stars. Submission 1: test, possibly final Submission 2: retry as submission 1 seemed to fail Submission 3: updated orientations to enable schedulability. Also required switching WedgeA observations to WedgeB. Submission 4: updated proposal description and short exposures Submission 5: switched back from WedgeB to WedgeA, following discussion with CS Submission 6: restricted orientations further, following discussion with CS Submission 7: shortened final exposures to avoid orbital visibility overrun, following discussion with CS -738807666 ----- Attempting Submission 1 (Sun Aug 04 18:43:15 GMT 2024) ----- ----- Attempting Submission 2 (Sat Nov 02 02:30:15 GMT 2024) ----- HST Phase II Proposal 17741 successfully submitted. Receipt: # 17741-2 ----- Attempting Submission 3 (Sat Nov 02 02:48:08 GMT 2024) ----- ----- Attempting Submission 4 (Wed Dec 04 18:27:06 GMT 2024) ----- ----- Attempting Submission 5 (Fri Jan 10 22:30:20 GMT 2025) ----- ----- Attempting Submission 6 (Tue Jan 28 19:05:05 GMT 2025) ----- This observation is a close repeat of a previous observation. The errors and warnings (except the 1G warning) are the same to the best of our knowledge and otherwise are to be expected. Obtaining data in as close of a configuration as possible to the prior observation is critical. 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. 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 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. 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. Our team includes expertise in high-contrast disk and exoplanet observations, as well as debris disk and collision modeling. Members of our team proposed for, reduced, analyzed, and published the most recent epoch of STIS imaging on the proposed target, which we propose here to repeat. Principal Investigator: Dr. Kevin Wagner is a postdoctoral researcher at the University of Arizona. Dr. Wagner's expertise includes exoplanet imaging observations and statistical interpretations of the results of direct imaging surveys. Dr. Wagner led the development of the proposal and will lead the data reduction, interpretation, and publication of the results of the proposed program. Dr. Wagner also has expertise in circumstellar disk modeling. Prof. Daniel Apai is an expert on studies of extrasolar planets and planet-forming environments. Apai led eight HST programs as PI and has published a comprehensive paper on HST/STIS observations of the Beta Pictoris system, the target of this proposal. Mr. Arin Avsar is a graduate student at the University of Arizona working with Prof. Apai and Dr. Wagner. Mr. Avsar has over two years of experience with STIS data reduction and analysis. Mr. Avsar also has expertise in collisional modeling. This project will be a component of Mr. Avsar's Ph.D. thesis. Exoplanets and Exoplanet Formation 6 false false false false false false false true PRIMARY 0.0 0.0 false SUPPORTED STAR A4-A9 V-IV Beta Pictoris, debris disk: semi-major axis P.A.: +30.8 degree (E of N) A6V J2000 J2000 B=4.03 CALIBRATION POINT SPREAD FUNCTION PSF calibrator for Beta Pictoris HD50241 J2000 J2000 B=3.48 STIS/CCD Imaging Yes No WEDGEB1.0 STIS/CCD Imaging Yes No WEDGEB1.0 STIS/CCD Imaging Yes No WEDGEB1.0 Timing link suitability includes constraints ([02 After 01 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. 1738090878075 /private/var/folders/8g/2w2vxm493pz_y2gh62_qp2b80000gn/T/OPVisit18324417485106511550.xml 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. (Tic-Visit :proposal-id 17741 :visit-id "01" :proposal-version -1 :trans-version "20240604" :date "28-Jan-2025 12:01:17.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 303152 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17741 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17741 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2714 :al-overhead-at-end 0 :internal-dur-at-end 333 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3078 :pcs-gap 0 ) true 1 1 Timing link suitability includes constraints ([02 After 01 by 0.0 to 0.1 days] [03 After 02 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. 1738090969682 /private/var/folders/8g/2w2vxm493pz_y2gh62_qp2b80000gn/T/OPVisit10159838856715893225.xml 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. (Tic-Visit :proposal-id 17741 :visit-id "02" :proposal-version -1 :trans-version "20240604" :date "28-Jan-2025 12:02:48.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 332336 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17741 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17741 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2748 :al-overhead-at-end 0 :internal-dur-at-end 365 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3119 :pcs-gap 0 ) true 1 1 Timing link suitability includes constraints ([03 After 02 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. 1738091009202 /private/var/folders/8g/2w2vxm493pz_y2gh62_qp2b80000gn/T/OPVisit9215206056899375061.xml 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. (Tic-Visit :proposal-id 17741 :visit-id "03" :proposal-version -1 :trans-version "20240604" :date "28-Jan-2025 12:03:28.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 303152 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17741 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17741 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2714 :al-overhead-at-end 0 :internal-dur-at-end 333 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3078 :pcs-gap 0 ) true 1 1