Anchoring Mass Loss Rate in the Young Sub-Neptune V1298 Tau c

0 Assigned ID: 7048 ----- Attempting Submission 1 (Tue Apr 14 04:37:49 GMT 2026) ----- HST Phase I Proposal 7048 successfully submitted. Receipt: # 7048-1 ----- Attempting Submission 2 (Wed Apr 15 16:37:48 GMT 2026) ----- HST Phase I Proposal 7048 successfully submitted. Receipt: # 7048-2 ----- Attempting Submission 3 (Wed Apr 15 17:52:12 GMT 2026) ----- STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL LONG VISIT LIKELY TO INTERSECT THE SAA STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL LONG VISIT LIKELY TO INTERSECT THE SAA STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL STIS SCIENCE TOO FAR FROM WAVECAL 0 ----- Attempting Submission 1 (Thu Jul 30 19:46:22 GMT 2026) ----- SAA passage is ok for CCD Anchoring Mass Loss Rate in the Young Sub-Neptune V1298 Tau c What shapes the exoplanet radius valley between super-Earths and sub-Neptunes: XUV-driven photoevaporation or core-powered mass loss? Direct mass-loss measurements during the first ~100 Myr when escape peaks are the key test. Current He I 1083 nm fits suffer an order-of-magnitude (T, Mdot) degeneracy; a multi-line hydrogen diagnostic breaks it. We propose 20 HST orbits (2 transits) of STIS G750M to detect H-alpha atmospheric escape from V1298 Tau c, a 23 Myr sub-Neptune (P=8.25 d, Rp~5.6 R_Earth, Mp~4.7 M_Earth) at the upper edge of the radius valley. The JWST NIRISS/SOSS transit already reveals a strong He I 1083 nm excess (~3400 ppm) and the first Paschen-alpha 1875 nm escape detection on any exoplanet (~2300 ppm), both with trailing tails >2 hr past egress. HST H-alpha completes the first simultaneous H-alpha + Pa-alpha + He I escape measurement on any exoplanet. The H-alpha/Pa-alpha depth ratio probes the n=2 and n=3 excited-hydrogen populations, providing a Balmer-Paschen thermometer that breaks the (T, Mdot) degeneracy. Combined with the JWST He I depth and non-LTE modeling framework, we will constrain the outflow temperature to ~5-10% and the mass-loss rate to better than 0.1 dex, an order-of-magnitude improvement over single-line analyses. Only HST/STIS delivers the ~15 hr continuous stare and few-hundred-ppm stability needed to resolve the post-egress tail; ground-based H-alpha and He I campaigns on V1298 Tau c have failed due to limited phase coverage. This measurement provides a critical calibration anchor for photoevaporation vs. core-powered mass-loss models and establishes a multi-line diagnostic framework for the growing sample of young transiting planets. We will observe two transits of the 23 Myr sub-Neptune V1298 Tau c with STIS/CCD G750M centered at 6581 A (covering H-alpha at 6563 A) through the 52X2 slit, to measure H-alpha absorption from the escaping atmosphere. Each visit is a single uninterrupted block of 10 orbits (~15 hr). Because the JWST NIRISS He I and Pa-alpha light curves show an asymmetric escape signature with a trailing tail extending more than 2 hr past egress, the transit is deliberately not centered in the visit: the phase constraint starts each visit 5.0-4.5 hr before mid-transit, giving ~2 orbits of pre-ingress baseline, the full 4.8 hr transit, the post-egress tail, and ~3 orbits of post-tail baseline to anchor the out-of-transit flux and recover the true transit depth. The phase constraint uses a JWST-anchored ephemeris (T0 = 2460924.7690 BJD_TDB from the 2025 Sep 6 NIRISS transit; P = 8.24924 d from the 2021 CHEOPS to 2025 JWST transit baseline). Each visit begins with a CCD target acquisition (F28X50LP), followed by time-series spectroscopy: 8 exposures of 238 s in orbit 1 and 10 per orbit thereafter (98 total per visit, ~260 s cadence). We acknowledge that these 10-orbit visits exceed 6 orbits and will execute under shared-risk long-stare scheduling in reduced gyro mode. Guangwei Fu has extensive experience with HST observations of exoplanet atmospheres. He is the PI and Co-I of multiple HST programs. David Sing has extensive experience with HST, Spitzer, and JWST observations of exoplanet atmospheres. He is a PI of multiple large HST and JWST Transiting Exoplanet Program. Joshua Lothringer is an expert in atmospheric modeling and HST observation. Exoplanets and Exoplanet Formation 6 false false false false false false false SUPPORTED STAR K III-I 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 STIS/CCD Spectroscopic No No G750M 6581 /private/var/folders/dz/kgqb_rsn0tg8yt4qd0dz3h9c0000gn/T/OPVisit11379686124931640095.xml 1785440360146 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. V1298 Tau c transit 1 of 2. 10 continuous orbits in a single visit (unbroken block). Phase constraint places visit start ~5.0-4.5 hr before predicted mid-transit: ~2 orbits pre-ingress baseline, full T14=4.67 hr transit, and post-egress coverage of the trailing tail plus ~2 orbits post-tail baseline. Shared-risk long-stare scheduling (>6 orbits) acknowledged in Phase I special requirements. (Tic-Visit :proposal-id 18432 :visit-id "01" :proposal-version -1 :trans-version "20260618" :date "30-Jul-2026 15:39:18.0" :trans-errors '(:WARNINGS 89 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 10 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 241520 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18432 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2515 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 4 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 5 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 6 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 7 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 8 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 9 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "01" :orbit-number 10 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 123 :internal-dur-at-end 328 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) true 10 0 CCD target acquisition. Verify exposure time with STIS ETC for V=10.12 K1.5 star (scaled from heritage programs). Explicit WAVECAL; auto-wavecals disabled on science exposures. /private/var/folders/dz/kgqb_rsn0tg8yt4qd0dz3h9c0000gn/T/OPVisit10282708155587144799.xml 1785440510284 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. V1298 Tau c transit 2 of 2. 10 continuous orbits in a single visit (unbroken block). Phase constraint places visit start ~5.0-4.5 hr before predicted mid-transit: ~2 orbits pre-ingress baseline, full T14=4.67 hr transit, and post-egress coverage of the trailing tail plus ~2 orbits post-tail baseline. Shared-risk long-stare scheduling (>6 orbits) acknowledged in Phase I special requirements. (Tic-Visit :proposal-id 18432 :visit-id "02" :proposal-version -1 :trans-version "20260618" :date "30-Jul-2026 15:41:48.0" :trans-errors '(:WARNINGS 89 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 10 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 241520 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18432 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2515 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 4 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 5 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 6 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 7 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 8 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 9 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18432 :visit-id "02" :orbit-number 10 :pcs-time 380 :si-vis-utilization 2596 :al-overhead-at-end 123 :internal-dur-at-end 328 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) true 10 0 CCD target acquisition. Verify exposure time with STIS ETC for V=10.12 K1.5 star (scaled from heritage programs). Explicit WAVECAL; auto-wavecals disabled on science exposures.