17501( 8) - 01-Jul-2024 15:52:06 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17501 Version: 8 Check-in Time: 01-Jul-2024 15:52:06 STScI Edit Number: 4 Title Lone Lion or Part of a Pride: Proper Motion and Orbit of Leo P ------------------------------------------------------------------------------------ Type Cycle GO 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Paul Bennet Space Telescope Science Institute Y CoI: Dr. Sangmo Tony Sohn Space Telescope Science Institute Y CoI: Dr. Roeland P. van der Marel Space Telescope Science Institute N CoI: Dr. Mattia Libralato INAF - Istituto di Astrofisica Spaziale N CoI: Dr. Mark Fardal Eureka Scientific Inc. N CoI: Dr. Ekta Patel University of Utah N CoI: Dr. Laura L. Watkins Space Telescope Science Institute - ESA - N JWST CoI: Dr. Andres del Pino Molina Centro de Estudios de Fisica del Cosmos de N Aragon CoI: Dr. Eduardo Vitral Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract We propose to measure the first proper motion (PM) of a galaxy outside the LG by observing Leo P, a low mass, very low metallicity dwarf beyond the edge of the Local Group (LG, D=1.6 Mpc). By combining the new HST PM with the existing line-of-sight velocity, position and distance, we will precisely determine Leo P's trajectory, and compare the orbital characteristics and timescale with the existing star formation history (SFH). This will enable us to address several key questions such as: Is Leo P a member of the Antlia-Sextans group (ASG) or is it truly isolated? If it is part of the ASG, how did that dwarf galaxy group form? What is the transverse motion of galaxies outside the zero-velocity sphere of the LG? How does the SFH of Leo P relate to its environment, and are the sequence of bursts and quenches seen in its SFH driven by internal or external processes? And what are the implications for galaxy evolution at low masses? Leo P is far too distant and faint to be studied by Gaia. Only HST has the depth, astrometric precision and long time baselines via its archives to start measuring PMs of galaxies outside the LG. Thus, with Hubble's exceptional longevity and stability, we are able to continue to push back the frontiers of extra-galactic science. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will observe a single target field of the dwarf galaxy Leo P using ACS/WFC. This target field has deep ACS/WFC imaging data in the HST archive. In this program, the target field will be observed using the same telescope pointings and orientations as the first-epoch to maximize the overlaps of the observed fields between first- and second-epoch data. This will also minimize position-dependent uncertainties originating from imperfect CTE and geometric distortion corrections. To measure PMs, it is sufficient to observed only in one filter. Therefore, we will image all target fields using the F814W filter to measure PMs. Individual exposure times will be a half-orbit long to match 17501( 8) - 01-Jul-2024 15:52:06 - [ 2] the first-epoch, and we will use dithered patterns specially designed to maxmimuze pixel-phase coverage. We have divided our observqtions into 4 visits of 6 exposures (3 orbits) and a single visit of 8 exposures (4 orbits). For these seperate visits we added Timinig Requirements "GROUP WITHIN 30D" so that they can be treated as single epoch data for astrometric analyses. ------------------------------------------------------------------------------------ 17501( 8) - 01-Jul-2024 15:52:06 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 LEO-P GALAXY, DWARF RA=10H21M48.1157S, J2000 V = 16.8 ELLIPTICAL, STAR DEC=+18D05'33.80" FORMING REGION Reference Frame: Other: SIMBAD Extended: YES 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) 2015.5 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 17501( 8) - 01-Jul-2024 15:52:06 - [ 4] Visit: 01 (LeoP-V1) Visit Requirements: ORIENT 95.02D TO 95.02 D; GROUP 01, 02, 03, 04, 05, 06 WITHIN 30D On Hold Comments: Additional Comments: This is a 3 orbit visit for Leo P. 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 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0, 0 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.2228, 0.1158 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.0998, 0.2303 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.3225, 0.3460 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1199 S POS TARG 0.4075, 0.0306 (1199 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1199 S POS TARG 0.6304, 0.1464 (1199 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 | ------------------------------------------------------------------------------------------------------------------------------------ LEO-P 1 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 2 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 3 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 4 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 5 ACS/WFC ACCUM WFCENTER F814W none none none none 3 N/A LEO-P 6 ACS/WFC ACCUM WFCENTER F814W none none none none 3 N/A 17501( 8) - 01-Jul-2024 15:52:06 - [ 5] Visit: 02 (LeoP-V2) Visit Requirements: ORIENT 95.02D TO 95.02 D; GROUP 02, 01, 03, 04, 05, 06 WITHIN 30D On Hold Comments: Additional Comments: This is a 3 orbit visit for Leo P. 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 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.6304, 0.1464 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.7302, 0.3767 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.0018, 0.4085 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.2246, 0.5243 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.1017, 0.6388 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.3244, 0.7545 (1189 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 | ------------------------------------------------------------------------------------------------------------------------------------ LEO-P 1 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 2 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 3 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 4 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 5 ACS/WFC ACCUM WFCENTER F814W none none none none 3 N/A LEO-P 6 ACS/WFC ACCUM WFCENTER F814W none none none none 3 N/A 17501( 8) - 01-Jul-2024 15:52:06 - [ 6] Visit: 03 (LeoP-V3) Visit Requirements: ORIENT 95.02D TO 95.02 D; GROUP 03, 01, 02, 04, 05, 06 WITHIN 30D On Hold Comments: Additional Comments: This is a 3 orbit visit for Leo P. 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 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.4093, 0.4392 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.6322, 0.5550 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.5091, 0.6695 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.7320, 0.7852 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.3438, 0.2386 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.5666, 0.3544 (1189 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 | ------------------------------------------------------------------------------------------------------------------------------------ LEO-P 1 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 2 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 3 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 4 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 5 ACS/WFC ACCUM WFCENTER F814W none none none none 3 N/A LEO-P 6 ACS/WFC ACCUM WFCENTER F814W none none none none 3 N/A 17501( 8) - 01-Jul-2024 15:52:06 - [ 7] Visit: 04 (LeoP-V4) Visit Requirements: ORIENT 95.02D TO 95.02 D; GROUP 04, 01, 02, 03, 05, 06 WITHIN 30D On Hold Comments: Additional Comments: This is a 3 orbit visit for Leo P. 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 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.4436, 0.4689 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.6663, 0.5846 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.7513, 0.2692 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.9742, 0.3850 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.8511, 0.4995 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 1.0740, 0.6153 (1189 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 | ------------------------------------------------------------------------------------------------------------------------------------ LEO-P 1 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 2 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 3 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 4 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 5 ACS/WFC ACCUM WFCENTER F814W none none none none 3 N/A LEO-P 6 ACS/WFC ACCUM WFCENTER F814W none none none none 3 N/A 17501( 8) - 01-Jul-2024 15:52:06 - [ 8] Visit: 05 (LeoP-V5) Visit Requirements: ORIENT 95.02D TO 95.02 D; GROUP 05, 01, 02, 03, 04 WITHIN 30D On Hold Comments: Additional Comments: This is a 2 orbit visit for Leo P. 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 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.3456, 0.6471 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.5684, 0.7629 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.4455, 0.8774 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.6682, 0.9931 (1189 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 | ------------------------------------------------------------------------------------------------------------------------------------ LEO-P 1 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 2 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 3 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 4 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A 17501( 8) - 01-Jul-2024 15:52:06 - [ 9] Visit: 06 (LeoP-V6) Visit Requirements: ORIENT 95.02D TO 95.02 D; GROUP 06, 01, 02, 03, 04 WITHIN 30D On Hold Comments: Additional Comments: This is a 2 orbit visit for Leo P. 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 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.7531, 0.6778 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.9760, 0.7936 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.8529, 0.9081 (1189 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 1.0758, 1.0238 (1189 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 | ------------------------------------------------------------------------------------------------------------------------------------ LEO-P 1 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 2 ACS/WFC ACCUM WFCENTER F814W none none none none 1 N/A LEO-P 3 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A LEO-P 4 ACS/WFC ACCUM WFCENTER F814W none none none none 2 N/A 17501( 8) - 01-Jul-2024 15:52:06 - [ 10] Visit: 51 (LeoP-V51) Visit Requirements: On Hold Comments: Additional Comments: This is a two orbit visit to repeat failed observations from visits 1 & 5. 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 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.4075, 0.0306 see below (1132 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.6304, 0.1464 see below (1132 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.4455, 0.8774 see below (1163 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LEO-P ACS/WFC ACCUM WFCENTER F814W 1 1189 S POS TARG 0.6682, 0.9931 see below (1163 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 | ------------------------------------------------------------------------------------------------------------------------------------ LEO-P 1 ACS/WFC ACCUM WFCENTER F814W none none none none 1 1132.0 S LEO-P 2 ACS/WFC ACCUM WFCENTER F814W none none none none 1 1132.0 S LEO-P 3 ACS/WFC ACCUM WFCENTER F814W none none none none 2 1163.0 S LEO-P 4 ACS/WFC ACCUM WFCENTER F814W none none none none 2 1163.0 S 17501( 8) - 01-Jul-2024 15:52:06 - [ 11] Summary Form for Proposal 17501 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFCENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 01, 02, 03, 04, 05, 06 WITHIN 30D, GROUP 02, 01, 03, 04, 05, 06 WITHIN 30D, GROUP 03, 01, 02, 04, 05, 06 WITHIN 30D, GROUP 04, 01, 02, 03, 05, 06 WITHIN 30D, GROUP 05, 01, 02, 03, 04 WITHIN 30D, GROUP 06, 01, 02, 03, 04 WITHIN 30D, ORIENT 95.02D TO 95.02 D, POS TARG 0, 0, POS TARG 0.0018, 0.4085, POS TARG 0.0998, 0.2303, POS TARG 0.1017, 0.6388, POS TARG 0.2228, 0.1158, POS TARG 0.2246, 0.5243, POS TARG 0.3225, 0.3460, POS TARG 0.3244, 0.7545, POS TARG 0.3438, 0.2386, POS TARG 0.3456, 0.6471, POS TARG 0.4075, 0.0306, POS TARG 0.4093, 0.4392, POS TARG 0.4436, 0.4689, POS TARG 0.4455, 0.8774, POS TARG 0.5091, 0.6695, POS TARG 0.5666, 0.3544, POS TARG 0.5684, 0.7629, POS TARG 0.6304, 0.1464, POS TARG 0.6322, 0.5550, POS TARG 0.6663, 0.5846, POS TARG 0.6682, 0.9931, POS TARG 0.7302, 0.3767, POS TARG 0.7320, 0.7852, POS TARG 0.7513, 0.2692, POS TARG 0.7531, 0.6778, POS TARG 0.8511, 0.4995, POS TARG 0.8529, 0.9081, POS TARG 0.9742, 0.3850, POS TARG 0.9760, 0.7936, POS TARG 1.0740, 0.6153, POS TARG 1.0758, 1.0238 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names LEO-P ------------------------------------------------------------------------------------------------------------------------------------