15971( 9) - 22-Feb-2021 17:51:06 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15971 Version: 9 Check-in Time: 22-Feb-2021 17:51:06 STScI Edit Number: 2 Title Investigating the origins of large-scale spiral arms around a T Tauri star ------------------------------------------------------------------------------------ Type Cycle GO 27 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jane Huang University of Michigan Y CoI: Dr. Alycia J. Weinberger Carnegie Institution of Washington N CoI: Dr. Karin Oberg Harvard University N CoI: Dr. Sean M Andrews Smithsonian Institution Astrophysical N Observatory CoI: Dr. Edwin Anthony Bergin University of Michigan N CoI: Mr. Felipe Mauricio Alarcon University of Michigan N ------------------------------------------------------------------------------------ Abstract Despite the steadily increasing number of detections of spiral arms in protoplanetary disks over the past two decades, their origins remain enigmatic. The leading hypotheses are that the arms are due to perturbations from massive protoplanets or from gravitational instabilities, but neither mechanism has been confirmed for any protoplanetary disk. Recent ALMA observations of the T Tauri star RU Lup reveal multiple spiral arms in 12CO emission stretching out to nearly 1000 au from the star. The clumpy arms and large-scale non-Keplerian kinematics are suggestive of origins in gravitational instabilities. To investigate this possibility further, we propose for STIS coronagraphic observations to trace the large-scale distribution of material around RU Lup in scattered light. In particular, we are searching for 1) evidence of infalling remnant envelope material that may be responsible for the non-Keplerian kinematics and 2) dust counterparts of the molecular spiral arms, which can place constraints on the orientation of the arms relative to the disk based on how they are illuminated by starlight. A combined analysis of the deep ALMA CO maps and HST scattered light maps of RU Lup would provide the best opportunity yet to study how material may be transported from the large-scale circumstellar environment to small disk scales and induce disk instabilities. ------------------------------------------------------------------------------------ Observations Description ------------------------ To image the RU Lup system, the proposed program follows a procedure similar to that employed by HST Program 12228 to image PDS 66 and other circumstellar disks. The program consists of 3 orbits with RU Lup as the target and one orbit dedicated to observing the PSF reference star, HD 142709. For each orbit, guide star acquisition takes 6m33s, and the coronagraphic acquisition takes 4-5 minutes. For acquisition of RU Lup, we use the F28x50LP filter and an exposure time of 0.2 seconds to achieve a S/N of 184. For acquisition of the brighter HD 142709, we use the F24ND3 filter to achieve S/N=120 in 1.2 seconds. The first science observations are three short exposures of 203 s each under the WEDGEA0.6 coronagraph, with an inner working 15971( 9) - 22-Feb-2021 17:51:06 - [ 2] angle of 0.3''. The integration time is set to avoid exceeding 80% full well at the edge of the wedge. We will use a subarray readout of SIZEAXIS=136 pixels, centered on the target. The inner working angle of WEDGEA0.6 is necessary for imaging the disk-halo transition region (as constrained by published SPHERE observations of this source), but the outer working angle is not large enough to overlap with all of the CO emission around RU Lup, which extends to 8''. Therefore, we will move to the WEDGEA1.0 location (requiring another 29 s) because this aperture provides a larger field of view (>10'' in every direction from the star) and enables longer exposures without saturation. Because the WedgeA1.0 aperture is 214 pixels from the edge of the CCD, we will use a subarray readout of SIZEAXIS=426 pixels, centered on the target, to reduce the CCD read time and avoid doing a buffer dump until the end of the orbital visibility. Note: We obtain a "subarray off detector warning" when using SIZEAXIS=136 pixels for the WEDGEA0.6 position. Communication with our contact scientist indicates that this is an APT software issue that does not pose an issue for the flight software. The coronagraphic wedges and diffraction spikes, under which good PSF subtraction cannot be performed, block a substantial portion of the field of view. Therefore, we have to take observations at multiple telescope orientations. This also acts as a rotational dither and allows us to verify that structures seen at one orientation are truly from RU Lup. At any given time, the maximum roll available is ~30 degrees. Three orientations with as much roll as possible will produce the cleanest image. We seek rolls of 24-30 degrees to produce an image without occulted areas in the outer disk and in the spiral arm region. Each orbit will be contained in a separate visit due to changes in orientation/target. The three coronagraphic orbits at different orientations must be executed sequentially to minimize PSF-subtraction residuals due to the time-variation in the HST optical assembly (often referred to as ''breathing''). Similarly, we must observe a PSF reference star, HD 142709, in another sequential orbit. The PSF star, which is relatively close to RU Lup in the sky and chosen to be a nearly perfect color match based on Gaia photometry, is required because of the unfiltered large bandpass of the STIS/CCD. The PSF observations should follow the RU Lup observations in case the initial orbit is affected by the "breathing." Each orbit will be contained in a separate visit due to changes in orientation/target. Impact of reduced gyro mode: Based on Space Telescope's May 2016 report on reduced gyro mode implications, the main concern for the present program would be that scheduling the observations would become more difficult due to the necessity of performing sequential, contiguous visits with different roll angles. Although there is no absolute orientation requirement, roll angles between 24-30 degrees between orbits are sought in order to image areas that would otherwise be occulted by the coronagraph at a single orientation. However, for the sake of schedulability in the event of gyroscopic problems, roll angle requirements may be relaxed to 20 degrees. ------------------------------------------------------------------------------------ 15971( 9) - 22-Feb-2021 17:51:06 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 V-RU-LUP EXT-STAR, CIRCUMSTELLAR RA=15H56M42.3110S, J2000 V = 11.1 MATTER, PRE-MAIN DEC=-37D49'15.47" SEQUENCE STAR, PROTOPLANETARY DISK Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. The V magnitude is taken from Gahm et al. 1993. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -9.74431465715155E-4 -0.023234 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 HD-142709 STAR, K V-IV RA=15H57M40.7430S, J2000 V = 8.055 DEC=-42D37'27.24" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -0.02327763445728997 -0.190894 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 15971( 9) - 22-Feb-2021 17:51:06 - [ 4] Visit: 01 (V1-RULUP) Visit Requirements: PCS MODE FINE; GUID TOL 0.005"; GYRO MODE 3GOBAD; ORIENT -30D TO -24D FROM 02 On Hold Comments: Additional Comments: First of three visits to RU Lup, with one visit to a PSF interleaved. The visits must be executed sequentially. Orientation: The first visit should have a relative orientation of -30 to -24 degrees from the second visit, with no absolute orientation constraint on the second visit. Ideally, the relative orientation should be as close to -30 degrees as possible. Timing: This visit should come immediately before visit 2. 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 V-RU-LUP STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 0.2 S (0.2 S) Comments: V=11.1, Spectral Type = K7, SNR=184 ------------------------------------------------------------------------------------------------------------------------------------ 2 V-RU-LUP STIS/CCD ACCUM WEDGEA0.6 MIRROR CR-SPLIT=3, GAIN=4, 1 618 S (618 SIZEAXIS2=136 S) Comments: Exposure time selected to avoid exceeding 80% of full well at 0.3", scaled from counts measured for PDS 66 (V=10.35) from Program 12228 and Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019). RU Lup is V=11.1. ------------------------------------------------------------------------------------------------------------------------------------ 3 V-RU-LUP STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=5, GAIN=4, 1 1635 S SIZEAXIS2=426 (1635 S) Comments: According to Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019), 80% of full-well at 0.5" is achieved in 74 s for V=7.96. RU Lup is V=11.1, so 80% of full-well is expected in 1330 seconds. In order to divide the remaining orbit visibility time evenly by 5 sub-exposures, we set the time for each sub-exposure to 320 seconds. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 1 1 N/A 6 15971( 9) - 22-Feb-2021 17:51:06 - [ 5] 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 2 1 N/A 6 V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 3 1 N/A 6 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 15971( 9) - 22-Feb-2021 17:51:06 - [ 6] Visit: 02 (V2-RULUP) Visit Requirements: PCS MODE FINE; GUID TOL 0.005"; GYRO MODE 3GOBAD; AFTER 01 BY 0.5 Orbits TO 1.5 Orbits On Hold Comments: Additional Comments: Second of three visits to RU Lup, with one visit to a PSF interleaved. The visits must be executed sequentially. Orientation: There is no absolute orientation for this visit, but the preceding visit should have a relative orientation of -30 to -24 degrees from this visit. Timing: This visit should come immediately after visit 1 and immediately before visit 3. 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 V-RU-LUP STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 0.2 S (0.2 S) Comments: V=11.1, Spectral Type = K7, SNR=184 ------------------------------------------------------------------------------------------------------------------------------------ 2 V-RU-LUP STIS/CCD ACCUM WEDGEA0.6 MIRROR CR-SPLIT=3, GAIN=4, 1 618 S (618 SIZEAXIS2=136 S) Comments: Exposure time selected to avoid exceeding 80% of full well at 0.3", scaled from counts measured for PDS 66 (V=10.35) from Program 12228 and Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019). RU Lup is V=11.1. ------------------------------------------------------------------------------------------------------------------------------------ 3 V-RU-LUP STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=5, GAIN=4, 1 1635 S SIZEAXIS2=426 (1635 S) Comments: According to Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019), 80% of full-well at 0.5" is achieved in 74 s for V=7.96. RU Lup is V=11.1, so 80% of full-well is expected in 1330 seconds. In order to divide the remaining orbit visibility time evenly by 5 sub-exposures, we set the time for each sub-exposure to 320 seconds. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 1 1 N/A 6 V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 2 1 N/A 6 15971( 9) - 22-Feb-2021 17:51:06 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 3 1 N/A 6 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 15971( 9) - 22-Feb-2021 17:51:06 - [ 8] Visit: 03 (V3-PSF-RULUP) Visit Requirements: PCS MODE FINE; GUID TOL 0.005"; GYRO MODE 3GOBAD; AFTER 02 BY 0.5 Orbits TO 1.5 Orbits On Hold Comments: Additional Comments: Visit to PSF reference star (HD 142709), interleaved between visits to the science target (RU Lup). The visits must be executed sequentially. Orientation: There is no absolute orientation for this visit. Timing: This visit should come immediately after visit 2 and immediately before visit 4. 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 HD-142709 STIS/CCD ACQ F25ND3 MIRROR ACQTYPE=POINT 1 1.2 S (1.2 S) Comments: V=8.1, Spectral Type = K4, SNR=120, exposure time rounded to nearest 0.1 seconds ------------------------------------------------------------------------------------------------------------------------------------ 2 HD-142709 STIS/CCD ACCUM WEDGEA0.6 MIRROR CR-SPLIT=8, GAIN=4, 1 400 S (400 SIZEAXIS2=136 S) Comments: Exposure time selected to avoid exceeding 80% of full well at 0.3", scaled from counts measured for PDS 66 (V=10.35) from Program 12228 and Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019). HD 142709 is V=8.1. ------------------------------------------------------------------------------------------------------------------------------------ 3 HD-142709 STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=8, GAIN=4, 1 680 S (680 SIZEAXIS2=426 S) Comments: According to Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019), 80% of full-well at 0.5" is achieved in 74 seconds for V=7.96. HD 142709 is V=8.1, so 80% of fulll-well is expected in 85 seconds. ------------------------------------------------------------------------------------------------------------------------------------ 4 HD-142709 STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=8, GAIN=4, 1 680 S (680 SIZEAXIS2=426 S) Comments: According to Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019), 80% of full-well at 0.5" is achieved in 74 seconds for V=7.96. HD 142709 is V=8.1, so 80% of full-well is expected in 85 seconds. ------------------------------------------------------------------------------------------------------------------------------------ 15971( 9) - 22-Feb-2021 17:51:06 - [ 9] 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD-142709 1 STIS/CCD ACQ F25ND3 MIRROR none none none none 1 N/A HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 1 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 2 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 3 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 4 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 5 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 6 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 7 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 8 1 N/A 6 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 15971( 9) - 22-Feb-2021 17:51:06 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 15971( 9) - 22-Feb-2021 17:51:06 - [ 11] Visit: 04 (V4-RULUP) Visit Requirements: PCS MODE FINE; GUID TOL 0.005"; GYRO MODE 3GOBAD; ORIENT 23D TO 30D FROM 02; AFTER 03 BY 0.5 Orbits TO 1.5 Orbits On Hold Comments: Additional Comments: Last of three visits to RU Lup, with one visit to a PSF interleaved. The visits must be executed sequentially. Orientation: This visit should have a relative orientation of 20 to 30 degrees from the second visit, with no absolute orientation constraint on the second visit. Ideally, the relative orientation should be as close to 30 degrees as possible. Timing: This visit should come immediately after visit 3. 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 V-RU-LUP STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 0.2 S (0.2 S) Comments: V=11.1, Spectral Type = K7, SNR=184 ------------------------------------------------------------------------------------------------------------------------------------ 2 V-RU-LUP STIS/CCD ACCUM WEDGEA0.6 MIRROR CR-SPLIT=3, GAIN=4, 1 618 S (618 SIZEAXIS2=136 S) Comments: Exposure time selected to avoid exceeding 80% of full well at 0.3", scaled from counts measured for PDS 66 (V=10.35) from Program 12228 and Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019). RU Lup is V=11.1. ------------------------------------------------------------------------------------------------------------------------------------ 3 V-RU-LUP STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=5, GAIN=4, 1 1635 S SIZEAXIS2=426 (1635 S) Comments: According to Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019), 80% of full-well at 0.5" is achieved in 74 s for V=7.96. RU Lup is V=11.1, so 80% of full-well is expected in 1330 seconds. In order to divide the remaining orbit visibility time evenly by 5 sub-exposures, we set the time for each sub-exposure to 320 seconds. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 1 1 N/A 6 15971( 9) - 22-Feb-2021 17:51:06 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 2 1 N/A 6 V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 3 1 N/A 6 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 15971( 9) - 22-Feb-2021 17:51:06 - [ 13] Visit: 05 (V2-RULUP-repeat) Visit Requirements: PCS MODE FINE; GUID TOL 0.005"; GYRO MODE 3GOBAD; ORIENT -30D TO -24D FROM 06; BEFORE 27-MAY-2021:00:00:00 On Hold Comments: Additional Comments: First of two repeated visits to RU Lup, followed by a PSF visit. The visits must be executed sequentially. Orientation: This visit should be offset by at least +/- 24 degrees from V1-RULup (previously executed successfully at 71 degrees) Timing: This visit should come immediately before the repeat of visit 04 (V4-RULup-repeat (06)). 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 V-RU-LUP STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 0.2 S (0.2 S) Comments: V=11.1, Spectral Type = K7, SNR=184 ------------------------------------------------------------------------------------------------------------------------------------ 2 V-RU-LUP STIS/CCD ACCUM WEDGEA0.6 MIRROR CR-SPLIT=3, GAIN=4, 1 618 S (618 SIZEAXIS2=136 S) Comments: Exposure time selected to avoid exceeding 80% of full well at 0.3", scaled from counts measured for PDS 66 (V=10.35) from Program 12228 and Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019). RU Lup is V=11.1. ------------------------------------------------------------------------------------------------------------------------------------ 3 V-RU-LUP STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=5, GAIN=4, 1 1635 S SIZEAXIS2=426 (1635 S) Comments: According to Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019), 80% of full-well at 0.5" is achieved in 74 s for V=7.96. RU Lup is V=11.1, so 80% of full-well is expected in 1330 seconds. In order to divide the remaining orbit visibility time evenly by 5 sub-exposures, we set the time for each sub-exposure to 320 seconds. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 1 1 N/A 6 15971( 9) - 22-Feb-2021 17:51:06 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 2 1 N/A 6 V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 3 1 N/A 6 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 15971( 9) - 22-Feb-2021 17:51:06 - [ 15] Visit: 06 (V4-RULUP-repeat) Visit Requirements: PCS MODE FINE; GUID TOL 0.005"; GYRO MODE 3GOBAD; ORIENT 318D TO 318 D; AFTER 05 BY 0.5 Orbits TO 1.5 Orbits; BEFORE 27-MAY-2021:00:00:00 On Hold Comments: Additional Comments: Second of two repeated visits to RU Lup, with one visit to a PSF following. The visits must be executed sequentially. Orientation: This visit should have a relative orientation of at least +/- 24 degrees from the successfully executed Visit 01 (V1-RULUP) and +/- 24 to 30 degrees from the repeat of visit 02 (V2-RULup-repeat (05)). A relative offset closer to +/- 30 degrees from the repeat of visit 02 (V2-RULup-repeat (05)) is preferred. Timing: This visit should come immediately after the repeat of Visit 02 (V2-RULup-repeat (05)). 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 V-RU-LUP STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 0.2 S (0.2 S) Comments: V=11.1, Spectral Type = K7, SNR=184 ------------------------------------------------------------------------------------------------------------------------------------ 2 V-RU-LUP STIS/CCD ACCUM WEDGEA0.6 MIRROR CR-SPLIT=3, GAIN=4, 1 618 S (618 SIZEAXIS2=136 S) Comments: Exposure time selected to avoid exceeding 80% of full well at 0.3", scaled from counts measured for PDS 66 (V=10.35) from Program 12228 and Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019). RU Lup is V=11.1. ------------------------------------------------------------------------------------------------------------------------------------ 3 V-RU-LUP STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=5, GAIN=4, 1 1635 S SIZEAXIS2=426 (1635 S) Comments: According to Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019), 80% of full-well at 0.5" is achieved in 74 s for V=7.96. RU Lup is V=11.1, so 80% of full-well is expected in 1330 seconds. In order to divide the remaining orbit visibility time evenly by 5 sub-exposures, we set the time for each sub-exposure to 320 seconds. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 15971( 9) - 22-Feb-2021 17:51:06 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 1 1 N/A 6 V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 2 1 N/A 6 V-RU-LUP 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 3 1 N/A 6 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 V-RU-LUP 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 15971( 9) - 22-Feb-2021 17:51:06 - [ 17] Visit: 07 (V3-PSF-RULUP-repeat) Visit Requirements: PCS MODE FINE; GUID TOL 0.005"; GYRO MODE 3GOBAD; AFTER 06 BY 0.5 Orbits TO 1.5 Orbits; BEFORE 27-MAY-2021:00:00:00 On Hold Comments: Additional Comments: Visit to PSF reference star (HD 142709), following the two repeated visits to the science target (RU Lup). The visits must be executed sequentially. Orientation: There is no absolute orientation constraint for this visit. Timing: This visit should come immediately after the repeat of visit 04 (V4-RULup-repeat (06)). 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 HD-142709 STIS/CCD ACQ F25ND3 MIRROR ACQTYPE=POINT 1 1.2 S (1.2 S) Comments: V=8.1, Spectral Type = K4, SNR=120, exposure time rounded to nearest 0.1 seconds ------------------------------------------------------------------------------------------------------------------------------------ 2 HD-142709 STIS/CCD ACCUM WEDGEA0.6 MIRROR CR-SPLIT=8, GAIN=4, 1 400 S (400 SIZEAXIS2=136 S) Comments: Exposure time selected to avoid exceeding 80% of full well at 0.3", scaled from counts measured for PDS 66 (V=10.35) from Program 12228 and Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019). HD 142709 is V=8.1. ------------------------------------------------------------------------------------------------------------------------------------ 3 HD-142709 STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=8, GAIN=4, 1 680 S (680 SIZEAXIS2=426 S) Comments: According to Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019), 80% of full-well at 0.5" is achieved in 74 seconds for V=7.96. HD 142709 is V=8.1, so 80% of fulll-well is expected in 85 seconds. ------------------------------------------------------------------------------------------------------------------------------------ 4 HD-142709 STIS/CCD ACCUM WEDGEA1.0 MIRROR CR-SPLIT=8, GAIN=4, 1 680 S (680 SIZEAXIS2=426 S) Comments: According to Table 1 in J. of Astronomical Telescopes, Instruments, and Systems, 5(3), 035003 (2019), 80% of full-well at 0.5" is achieved in 74 seconds for V=7.96. HD 142709 is V=8.1, so 80% of full-well is expected in 85 seconds. ------------------------------------------------------------------------------------------------------------------------------------ 15971( 9) - 22-Feb-2021 17:51:06 - [ 18] 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD-142709 1 STIS/CCD ACQ F25ND3 MIRROR none none none none 1 N/A HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 1 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 2 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 3 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 4 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 5 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 6 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 7 1 N/A 6 HD-142709 2 STIS/CCD ACCUM WEDGEA0. MIRROR none none none 8 1 N/A 6 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 HD-142709 3 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 1 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 2 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 3 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 4 1 N/A 0 15971( 9) - 22-Feb-2021 17:51:06 - [ 19] 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 | ------------------------------------------------------------------------------------------------------------------------------------ HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 5 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 6 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 7 1 N/A 0 HD-142709 4 STIS/CCD ACCUM WEDGEA1. MIRROR none none none 8 1 N/A 0 15971( 9) - 22-Feb-2021 17:51:06 - [ 20] Summary Form for Proposal 15971 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F25ND3, F28X50LP, WEDGEA0.6, WEDGEA1.0 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT, CR-SPLIT=3, CR-SPLIT=5, CR-SPLIT=8, GAIN=4, SIZEAXIS2=136, SIZEAXIS2=426 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 0.5 Orbits TO 1.5 Orbits, AFTER 02 BY 0.5 Orbits TO 1.5 Orbits, AFTER 03 BY 0.5 Orbits TO 1.5 Orbits, AFTER 05 BY 0.5 Orbits TO 1.5 Orbits, AFTER 06 BY 0.5 Orbits TO 1.5 Orbits, BEFORE 27-MAY-2021:00:00:00, GUID TOL 0.005", GYRO MODE 3GOBAD, ORIENT -30D TO -24D FROM 02, ORIENT -30D TO -24D FROM 06, ORIENT 23D TO 30D FROM 02, ORIENT 318D TO 318 D, PCS MODE FINE ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD-142709, V-RU-LUP ------------------------------------------------------------------------------------------------------------------------------------