HST proposal submission -354667709 Assigned ID: 6746 ----- Attempting Submission 1 (Thu Apr 10 21:52:00 GMT 2025) ----- Could not connect to APT Status Server Added BEFORE constraint and adjusted exposure time to avoid overruns. 1302187203 ----- Attempting Submission 1 (Thu Aug 14 05:54:32 GMT 2025) ----- HST Phase II Proposal 18114 successfully submitted. Receipt: # 18114-1 ----- Attempting Submission 2 (Mon Aug 18 05:38:30 GMT 2025) ----- ----- Attempting Submission 3 (Tue Nov 25 19:41:44 GMT 2025) ----- Status information not downloaded, let me know if this is somehow a problem. Unveiling Hidden Protoplanets: Direct Extinction Measurement at Optical Wavelengths in the Planet-Formed Gap of AS209 While disk substructures provide compelling indirect evidence for the presence of accreting protoplanets, direct detections remain frustratingly scarce and extinction by circumstellar and circumplanetary dust is often invoked as an explanation. AS 209bkg, a background star shining through the outer gap of the well-studied disk around AS 209, offers a unique opportunity to test this hypothesis. By performing transmission spectroscopy of AS 209bkg, we can directly measure the extinction caused by dust in a planet-forming disk gap for the first time. Existing data constrain the extinction at wavelengths longer than 1 um, but the extinction solutions diverge at shorter wavelengths. This is a critical spectral region for the search for protoplanets, as most searches for accretion signatures target the Halpha line at 0.656um - right where extinction may be strongest. We propose to use the imaging capabilities of WFC3 in three filters spanning 0.8-1.2um to detect AS 209bkg and measure the wavelength dependence of extinction across this key range. Our results will provide the first empirical calibration of optical dust attenuation in disk gaps and will directly inform the interpretation of low-yield Halpha imaging surveys, helping determine whether elusive protoplanets are truly missing or simply veiled in dust. The primary goal of our observations is to use the direct-imaging technique to detect a background star shining through the disk gap in the AS209 system. We will observe AS209 using WFC3/UVIS and WFC3/IR with the F814W, F098M and F125W filters for 8,2 and 2 consecutive orbits. We will use the UVIS2-C512C-SUB IRSUB256-FIX subarrays to reduce readout time and improve observing efficiency. The images will be taken using a box dithering pattern with a dithering distance of 0.02 and 0.065 arcsec (0.5 pixels) for UVIS and IR on both sides. This will allow reconstructing Nyquist-sampled images, which are necessary for the post-processing of high-contrast images. At each dithering position, several copies of exposures will be taken. The exposure time and iteration numbers are determined to maximize the point spread function signal to noise ratio, avoid saturation and maximize the usage of orbital visibility. Every visit contains one orbit. Observations are linked by timing requirements and will be executed continuously. To facilitate two-roll angular differential imaging, the second visit will have a 25 to 35 (80 to 100) degrees difference in telescope orientation for UVIS (IR) compared to those of the previous visit. For UVIS, every second visit will have the same orientation as two visits before. The orientation constraints ensure that in no visit the background star's signal (PA 110 deg) coincides with the position of one of the PSF spike. Based on suggestions from STScI and the contact scientist on a similar program executed during the past cycles, we switch on the FLASH and set the level to 20 to mitigate the CTE loss. This proposal contains expertise in the observational and theoretical aspect of detecting and characterizing faint sources in protoplanetary disks. The team has extensive experience in both ground- and space-based observations, in particular with high contrast imaging of exoplanets. - PI Gabriele Cugno is an expert in high contrast imaging using both ground-based and space observatories (VLT, HST, JWST). He is the PI of the HST Halpha program on AS209, of the JWST/NIRCam and SPHERE AS209bkg programs. He is also the PI of the ongoign VLTI/GRAVITY DDT program - co-PI Stefano Facchini is an expert of ALMA observations of protoplanetary disks, theory of planet-disk interactions, and has experience with high contrast imaging with JWST/NIRCam from a Cycle 1 program on the same source targeted in this proposal - co-I Yifan Zhou has PI'd several successful proposal to search for H-alpha emission from accreting planets with HST and will provide an excellent reduction of the HST data. - coIs Teague and Alarcon have a strong background in ALMA observations of disks, and planet disk interactinos as traced by gas kinematics. - coI Benisty has solid expertise in high contrast imaging, with particular emphasis in scattered light images of disks. - coI Bae is an expert in the theory of planet-disk interactions, and has led the discovery of the CPD candidate in AS 209 from ALMA data - coI Pueyo is a scientist at STScI, and have a strong background in high contrast imaging. He was part of the team that observed AS209 with HST/NICMOS in 2005 Exoplanets and Exoplanet Formation 6 false false false false false false SUPPORTED STAR K V-IV PROTOPLANETARY DISK 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. J2000 J2000 WFC3/IR Imaging No No F127M WFC3/IR Imaging No No F098M WFC3/UVIS Imaging No No F814W POS-TARG DITHER 0.02 LINE 0.02 false false 90 4 0 BOX 1 false POS-TARG DITHER 0.065 LINE 0.0605 false false 90 4 0 BOX 2 false /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit6010479320562799333.xml 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. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "01" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:39:04.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 164752 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2355 :al-overhead-at-end 51 :internal-dur-at-end 217 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 The exposure time to reach saturation is estimated to be 0.8 seconds. Given the large separation of the candidate, we plan to observe with exposures of 1.0 s, slightly saturating the PSF core. This will not affect our ability to center the image, as we can use the PSF spikes for that. This has been shown in past works on UVIS data. /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit859680440483642187.xml 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. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "02" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:39:05.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 164752 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2355 :al-overhead-at-end 51 :internal-dur-at-end 217 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 The exposure time to reach saturation is estimated to be 0.8 seconds. Given the large separation of the candidate, we plan to observe with exposures of 1.0 s, slightly saturating the PSF core. This will not affect our ability to center the image, as we can use the PSF spikes for that. This has been shown in past works on UVIS data. /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit2009945568901314682.xml Timing link suitability includes constraints ([04 After 03 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "03" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:39:06.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 164752 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2355 :al-overhead-at-end 51 :internal-dur-at-end 217 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 The exposure time to reach saturation is estimated to be 0.8 seconds. Given the large separation of the candidate, we plan to observe with exposures of 1.0 s, slightly saturating the PSF core. This will not affect our ability to center the image, as we can use the PSF spikes for that. This has been shown in past works on UVIS data. /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit12422800031201551245.xml Timing link suitability includes constraints ([04 After 03 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "04" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:39:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 164752 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "04" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2355 :al-overhead-at-end 51 :internal-dur-at-end 217 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 The exposure time to reach saturation is estimated to be 0.8 seconds. Given the large separation of the candidate, we plan to observe with exposures of 1.0 s, slightly saturating the PSF core. This will not affect our ability to center the image, as we can use the PSF spikes for that. This has been shown in past works on UVIS data. /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit17327100135937673785.xml Timing link suitability includes constraints ([06 After 05 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "05" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:39:08.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 164752 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "05" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2355 :al-overhead-at-end 51 :internal-dur-at-end 217 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 The exposure time to reach saturation is estimated to be 0.8 seconds. Given the large separation of the candidate, we plan to observe with exposures of 1.0 s, slightly saturating the PSF core. This will not affect our ability to center the image, as we can use the PSF spikes for that. This has been shown in past works on UVIS data. /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit674161749673963648.xml Timing link suitability includes constraints ([06 After 05 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "06" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:39:10.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 164752 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "06" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2355 :al-overhead-at-end 51 :internal-dur-at-end 217 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 The exposure time to reach saturation is estimated to be 0.8 seconds. Given the large separation of the candidate, we plan to observe with exposures of 1.0 s, slightly saturating the PSF core. This will not affect our ability to center the image, as we can use the PSF spikes for that. This has been shown in past works on UVIS data. /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit16856774515277838918.xml Timing link suitability includes constraints ([08 After 07 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "07" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:39:11.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 164752 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "07" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2355 :al-overhead-at-end 51 :internal-dur-at-end 217 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 The exposure time to reach saturation is estimated to be 0.8 seconds. Given the large separation of the candidate, we plan to observe with exposures of 1.0 s, slightly saturating the PSF core. This will not affect our ability to center the image, as we can use the PSF spikes for that. This has been shown in past works on UVIS data. /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit1396878244651661314.xml Timing link suitability includes constraints ([08 After 07 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "08" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:38:11.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 164752 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "08" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2355 :al-overhead-at-end 51 :internal-dur-at-end 217 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 The exposure time to reach saturation is estimated to be 0.8 seconds. Given the large separation of the candidate, we plan to observe with exposures of 1.0 s, slightly saturating the PSF core. This will not affect our ability to center the image, as we can use the PSF spikes for that. This has been shown in past works on UVIS data. /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit12821897442754505115.xml Timing link suitability includes constraints ([10 After 09 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. 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The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "10" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:35:32.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 705632 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "10" :obset-id "10" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "10" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2301 :al-overhead-at-end 0 :internal-dur-at-end 467 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit15822626468414328955.xml Timing link suitability includes constraints ([12 After 11 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "11" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:35:34.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 816064 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "11" :obset-id "11" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "11" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2514 :al-overhead-at-end 0 :internal-dur-at-end 304 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0 /private/var/folders/_s/c5xcf8451gq16lv_mg3mct780000gn/T/OPVisit4622897985883129267.xml Timing link suitability includes constraints ([12 After 11 by 0.0 to 0.1 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. The orientation requirements are meant to avoid the PSF spikes to end up at the position of the background source, which is located at a position angle of ~110 deg East of North. (Tic-Visit :proposal-id 18114 :visit-id "12" :proposal-version -1 :trans-version "20250929" :date "25-Nov-2025 20:35:36.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 816064 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18114 :visit-id "12" :obset-id "12" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18114 :visit-id "12" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2514 :al-overhead-at-end 0 :internal-dur-at-end 304 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2974 :pcs-gap 0 ) true 1 0