17768( 4) - 18-Dec-2024 18:36:11 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17768 Version: 4 Check-in Time: 18-Dec-2024 18:36:11 STScI Edit Number: 0 Title Detecting the UV Accretion Signatures from PDS-70b ------------------------------------------------------------------------------------ Type Cycle GO 32 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Laura Flagg The Johns Hopkins University Y CoI: Dr. Christopher Michael Rice University N Johns-Krull CoI: Dr. Andrea Isella Rice University N CoI: Dr. Alycia J. Weinberger Carnegie Institution of Washington N CoI: Prof. Ray Jayawardhana The Johns Hopkins University N CoI: Dr. James Muzerolle Page Space Telescope Science Institute N CoI: Dr. Thanawuth Thanathibodee Chulalongkorn University N CoI: Dr. Yifan Zhou The University of Virginia N CoI: Dr. Jake Turner Cornell University N ------------------------------------------------------------------------------------ Abstract Accretion is an essential step in gas giant planet-building and measuring the accretion rate illuminates the nature of planet-disk interactions as well as the timescale for and the process of planet formation. While there are numerous models for how planets may accrete material from the circumstellar disk in which they form, there is little consensus about the specifics given the lack of direct observational evidence. PDS-70b (a ~5 Myr-old giant planet) has had its accretion luminosity measured at H-alpha and in the continuum at 335 nm. However, the accretion rates derived from these measurements range over 2 orders of magnitude. For stars, the most accurate accretion indicators are shortward of 300 nm, as these more directly probe the accretion shock where infalling material impacts the surface. Similar observations of accreting planets are needed to better test whether an analogous process occurs in planet formation. We propose to observe PDS-70b between 120 nm and 300 nm at low resolution to search for accretion signatures in the UV to better constrain the accretion process on PDS 70b and measure a reliable accretion rate. We will observe PDS-70b at H-alpha both before and after each UV observation so we can calibrate the relationship between accretion signatures at H-alpha versus the UV, as is done for stars. We will also observe PDS-70b at medium resolution from 276 to 285 nm to measure the accretion line profile and constrain the planet's mass, a key quantity needed to reliably measure the accretion rate. These observations will provide some of the first UV observational data of planet accretion and will result in new and important insights into planet formation. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program aims to detect the UV flux from PDS 70b. The program is broken down into two visits. In one visit (5 orbits), we will acquire low-resolution spectra in order determine the flux from various UV lines and compare that to 17768( 4) - 18-Dec-2024 18:36:11 - [ 2] the planet's H-alpha flux, which we will also measure during that visit. In the other visit (3 orbits), we will acquire medium resolution spectra in order to resolve the line profile. We can capture both the star's and the planet's UV spectra by aligning the slit from STIS/MAMA at the planet's position angle using the 52 arcsec X0.2 arcsec slit. PDS-70b's apparent separation from its host star is large enough at the moment that the star's and the planet's signals will be spatially separated with STIS/MAMA spectroscopy, as shown in the original proposal. For the H-alpha observations, we will employ a four point dither pattern, as has been shown to work for previous observations of this system with WFC3/UVIS. We will use the same observation strategy as that of GO-17427, which observed this same system. The warning on FLASH level has been ignored based on prior observations of the system (GO-15830). For the low-resolution visit, after acquisition, we will start with the STIS/MAMA G2230L NUV observations for a partial orbit. We will then move to the STIS/MAMA G140L FUV observations for the remainder of the first orbit plus three full orbits. We finish with the WFC3 observations of H-alpha for an orbit. For the medium-resolution visit, after acquisition, we will spend the remainder of that orbit plus two full orbits observing the system with STIS/MAMA G230M (central wavelength 2800) NUV. ------------------------------------------------------------------------------------ 17768( 4) - 18-Dec-2024 18:36:11 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 2 PDS70 STAR, EXTRA-SOLAR RA=14H08M10.1540S +/- J2000 V = 3.13 V = 12.18 +/- 0.13 B=13.42 (Simbad); PLANETARY SYSTEM, K 0.0000397", DEC=-41D23'52.58" Swift uvw2 (1599-2256 A.) = 1.5e-13 V-IV, T TAURI STAR +/- 0.0000284" ergs/cm^2/s; uvwI (2253-2946 A.) = 2.7e-13 ergs/cm^2/s (ref. Joyce et al. 2020) Reference Frame: ICRS Extended: NO Comments: RA, Dec are from Simbad (referenced to Gaia DR2). RA, Dec errors, Proper Motion, Radial Velocity are from Gaia DR2. V mag and uncertainty are from range given in Simbad. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 -0.002636059339522487 -0.023823 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 17768( 4) - 18-Dec-2024 18:36:11 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.02 Line_Spacing 0.02 Coordinate_Frame POS-TARG Pattern_Orient 0 Angle_Between_Sides 90 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 17768( 4) - 18-Dec-2024 18:36:11 - [ 5] Visit: 01 (Low-res) Visit Requirements: ORIENT 116D TO 132 D; ORIENT 296D TO 312 D; BETWEEN 03-MAR-2025:00:00:00 AND 05-MAR-2025:23:59:59; BETWEEN 09-MAR-2025:00:00:00 AND 22-MAR-2025:23:59:59 On Hold Comments: Additional Comments: 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 PDS70 STIS/CCD ACQ F28X50LP MIRROR 1 .4 S (0.4 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 PDS70 STIS/NUV TIME-TA 52X0.2 G230L 2376 BUFFER-TIME=693 1 460 S (460 -MAMA G S) ------------------------------------------------------------------------------------------------------------------------------------ 3 PDS70 STIS/FUV TIME-TA 52X0.2 G140L 1425 BUFFER-TIME=5934 1 1193 S -MAMA G (1193 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 PDS70 STIS/FUV TIME-TA 52X0.2 G140L 1425 BUFFER-TIME=5934 1 2640 S -MAMA G (2640 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 PDS70 STIS/FUV TIME-TA 52X0.2 G140L 1425 BUFFER-TIME=5934 1 2640 S -MAMA G (2640 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 PDS70 STIS/FUV TIME-TA 52X0.2 G140L 1425 BUFFER-TIME=5934 1 2640 S -MAMA G (2640 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 PDS70 WFC3/UVI ACCUM UVIS2-C51 F656N 6 59 S (1416 PATTERN 1 7 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ PDS70 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A PDS70 2 STIS/NUV TIME-TA 52X0.2 G230L 2376 none none none none 1 N/A -MAMA G PDS70 3 STIS/FUV TIME-TA 52X0.2 G140L 1425 none none none none 1 N/A -MAMA G PDS70 4 STIS/FUV TIME-TA 52X0.2 G140L 1425 none none none none 2 N/A -MAMA G PDS70 5 STIS/FUV TIME-TA 52X0.2 G140L 1425 none none none none 3 N/A -MAMA G PDS70 6 STIS/FUV TIME-TA 52X0.2 G140L 1425 none none none none 4 N/A -MAMA G PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none 1 none 5 N/A S 12C-SUB 17768( 4) - 18-Dec-2024 18:36:11 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none 2 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none 3 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none 4 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none 5 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none 6 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none 1 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none 2 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none 3 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none 4 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none 5 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none 6 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none 1 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none 2 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none 3 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none 4 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none 5 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none 6 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 4 none 1 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 4 none 2 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 4 none 3 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 4 none 4 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 4 none 5 none 5 N/A S 12C-SUB PDS70 7 WFC3/UVI ACCUM UVIS2-C5 F656N 4 none 6 none 5 N/A S 12C-SUB 17768( 4) - 18-Dec-2024 18:36:11 - [ 7] Visit: 02 (medium-res) Visit Requirements: ORIENT 116D TO 132 D; ORIENT 296D TO 312 D; BETWEEN 03-MAR-2025:00:00:00 AND 05-MAR-2025:23:59:59; BETWEEN 09-MAR-2025:00:00:00 AND 22-MAR-2025:23:59:59 On Hold Comments: Additional Comments: 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 PDS70 STIS/CCD ACQ F28X50LP MIRROR 1 .4 S (0.4 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 PDS70 STIS/NUV TIME-TA 52X0.2 G230M 2800 BUFFER-TIME=693 1 2121 S -MAMA G (2121 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 PDS70 STIS/NUV TIME-TA 52X0.2 G230M 2800 BUFFER-TIME=693 1 2639 S -MAMA G (2639 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 PDS70 STIS/NUV TIME-TA 52X0.2 G230M 2800 BUFFER-TIME=693 1 2639 S -MAMA G (2639 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ PDS70 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A PDS70 2 STIS/NUV TIME-TA 52X0.2 G230M 2800 none none none none 1 N/A -MAMA G PDS70 3 STIS/NUV TIME-TA 52X0.2 G230M 2800 none none none none 2 N/A -MAMA G PDS70 4 STIS/NUV TIME-TA 52X0.2 G230M 2800 none none none none 3 N/A -MAMA G 17768( 4) - 18-Dec-2024 18:36:11 - [ 8] Summary Form for Proposal 17768 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2, F28X50LP, UVIS2-C512C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA, STIS/NUV-MAMA, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=5934, BUFFER-TIME=693 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 03-MAR-2025:00:00:00 AND 05-MAR-2025:23:59:59, BETWEEN 09-MAR-2025:00:00:00 AND 22-MAR-2025:23:59:59, ORIENT 116D TO 132 D, ORIENT 296D TO 312 D, PATTERN 1 7 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F656N, G140L, G230L, G230M, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names PDS70 ------------------------------------------------------------------------------------------------------------------------------------