0 Assigned ID: 6305 ----- Attempting Submission 1 (Wed Apr 09 22:52:29 GMT 2025) ----- HST Phase I Proposal 6305 successfully submitted. Receipt: # 6305-1 ----- Attempting Submission 2 (Thu Apr 10 15:37:53 GMT 2025) ----- HST Phase I Proposal 6305 successfully submitted. Receipt: # 6305-2 ----- Attempting Submission 3 (Thu Apr 10 16:40:03 GMT 2025) ----- Shelly--I have tried to make the links as loose as possible to aid in scheduling. Please let me know if there's anything I can do to improve that, such as removing the orient links. As long as the two orientations are different by between 5 and 30 degrees I'm not picky. -319580422 ----- Attempting Submission 1 (Fri Aug 08 15:34:41 GMT 2025) ----- Investigating Planet Formation in Real Time with the Dynamic Shadows Sweeping Across TW Hya In the era of HST, JWST, and ALMA, the initial conditions of planet formation will be laid bare through the direct imaging of planet forming regions around nearby young stars. As more and more disks are observed over multiple epochs, their dynamic and variable natures are revealed, opening new avenues of study. Recent HST/STIS observations of TW Hya have revealed as many as three shadows, originating from ~6au, sweeping across the disk with different periods. We propose to observe TW Hya using HST/STIS coronagraphy with a long term monitoring program to fill in badly needed orbital phase coverage of the shadows' motion and create a homogenous, high quality dataset with archival STIS observations. Our program will elucidate the physical origin of the shadows by measuring the shadow orbital periods, their inclination relative to our line of sight, and the position angles of where each shadow appears/disappears, thus elucidating the orbits of the shadow relative to the properties of the outer disk and constraining future dynamical and hydrodynamical models of planet-disk interactions. Additionally, our observations of the three shadow periods will determine if a singular Jupiter analog is responsible for launching multiple spiral arm shadows, or if the shadows are due to three less massive planets. Disk shadow imaging is a new tool for understanding the initial conditions of planet formation at radii inaccessible by other observations. This proposal patterned after 16991 with a combination of BAR10 Lower LEft, BAR10 Lower Right, and BAR5 and WEDGEA1.0 50CORON aperture positions. In this program we observe TW HYA in 2 visits interleaved with one visit of the PSF star. The first and last visit of TW Hya is oriented off nominal of between +/-5 to +/-30 degrees to enhance angular coverage of the protoplanetary disk. The team for this proposal is composed of several STIS and NICMOS experts in high contrast imaging (John Debes, STIS Team Lead and previous PI of 13753, 16228,16785,16991 STIS programs monitoring TW Hya; Alycia Weinberger, previous PI of several NICMOS and STIS disk proposals; and Laurent Pueyo, member of the ALICE reprocessing team and expert in post-processing techniques. Dean Hines was a member of the NICMOS IDT and is an expert in polarimetry, along with Schuyler Wolff. Joel Kastner is an expert in young stars. We also have several theoretical experts to interpret the data including Sally Dodson-Robinson, Inbok Yea, Rebecca Nealon, and Richard Alexander. Peter Plavchan is the lead of radial velocity monitoring of TW Hya and is a science team member of iShell. Exoplanets and Exoplanet Formation 6 false false false false false false SUPPORTED EXT-STAR EXTRA-SOLAR PLANETARY SYSTEM M V-IV PSF Reference for TW Hya J2000 J2000 EXT-STAR CIRCUMSTELLAR MATTER EXTRA-SOLAR PLANETARY SYSTEM T TAURI STAR J2000 Timing link suitability includes constraints ([002 After 001 by 0.1 to 0.2 days]) The scheduling data was generated by CASM 32.0. CASM was run in Phase I mode. STIS/CCD Imaging Yes No BAR5 STIS/CCD Imaging Yes No WEDGEA1.0 STIS/CCD Imaging Yes No BAR10 Timing link suitability includes constraints ([002 After 001 by 0.1 to 0.2 days]) The scheduling data was generated by CASM 32.0. CASM was run in Phase I mode. STIS/CCD Imaging Yes No BAR5 STIS/CCD Imaging Yes No WEDGEA1.0 STIS/CCD Imaging Yes No BAR10 Timing link suitability includes constraints ([02 After 01 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. /private/var/folders/9d/jk8g77fd2jx3sxdb33rhwx48000300/T/OPVisit17523888025196804665.xml TW Hya First sets of visits, containing three visits of TW Hya at different relative orientations with one PSF calibration observation interleaved. This is the first TW Hya visit in the first set. The four visits within each set must be executed sequentally in contiguous orbits interrupted only for Earth occultation. Orientation: We wish to schedule this visit (1) at -30 deg from Visit 2, with the absolute orientation of Visit 2 unconstrained. We allow a relative orientation tolerence from -15 deg to -30 deg to assist in guide star selection and scheduling. NOTE to PC: Schedule as close to -30 deg from Visit 2 as possible. Relative Timing: This visit (1) should immediately preceed visit (2). I.e., They should be executed sequentially in "back-to-back" orbits. BAR5 exposure times are selected to maximize SNR close to the star (~10-15/pixel up to inner working angle) and WEDGEA1.0 are selected to be as long as possible to ensure depth exterior to 1". (Tic-Visit :proposal-id 18059 :visit-id "01" :proposal-version -1 :trans-version "20250624" :date "08-Aug-2025 11:28:01.0" :trans-errors '(:WARNINGS 0 :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 29712 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18059 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18059 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2486 :al-overhead-at-end 0 :internal-dur-at-end 332 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2867 :pcs-gap 0 ) true 1 0 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 33.1. CASM was run in Phase II mode. /private/var/folders/9d/jk8g77fd2jx3sxdb33rhwx48000300/T/OPVisit7916122369585982111.xml PSF (HD 85512). PSF calibration target for TW Hya. V = 7.636. B - V = +1.15. Spex. K6Vk This is the PSF star calibrator for the flanking visits (1-4). We levy no orientation constraints on this visit (3). However, we choose this target since it has been used in the past for TW Hya. So as Visits 2 and 3 must be scheduled in sequential contiguous orbits, if scheduled at nominal roll (as we expect also Visit 2 will be) then we expect absolute orientations of Visits 2 and 3 to be very similar (within a few degrees). This is important so we maintain similar Sun and Beta angles for the science target and its PSF calibrator, Relative Timing: This visit (3) should immediately follow visit 2 and immediately precede visit 4. I.e., they should be executed sequentially in "back-to-back" orbits. (Tic-Visit :proposal-id 18059 :visit-id "02" :proposal-version -1 :trans-version "20250624" :date "08-Aug-2025 11:30:05.0" :trans-errors '(:WARNINGS 0 :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 165440 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18059 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18059 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2480 :al-overhead-at-end 0 :internal-dur-at-end 329 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2870 :pcs-gap 0 ) true 1 0 K6V nearby star V=7.65 Exptime rounded to nearest 0.1 second, assumed to get SNR=100. Timing link suitability includes constraints ([03 After 02 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. /private/var/folders/9d/jk8g77fd2jx3sxdb33rhwx48000300/T/OPVisit9612562140109924944.xml TW Hya three visits of TW HYA at different relative orientations with one PSF calibration observation interleaved. This is the second TW Hya visit in the first set. The four visits within the set must be executed sequentally in contiguous orbits interrupted only for Earth occultation. Orientation: There are no orientation constraints on this visit (2). This visit at nominal roll as scheduled by STScI. Visits 1, 3, 4 carry relative orientation constraints w.r.t. this visit. Relative Timing: This visit (2) should immediately follow Visit 1 and immediately preceed Visit 3 in back-to-back orbits. (Tic-Visit :proposal-id 18059 :visit-id "03" :proposal-version -1 :trans-version "20250624" :date "08-Aug-2025 11:30:30.0" :trans-errors '(:WARNINGS 0 :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 29712 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18059 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18059 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2486 :al-overhead-at-end 0 :internal-dur-at-end 332 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2867 :pcs-gap 0 ) true 1 0