15706( 9) - 15-Apr-2019 16:16:54 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15706 Version: 9 Check-in Time: 15-Apr-2019 16:16:54 STScI Edit Number: 0 Title Causes of activity in newly discovered active asteroids P/2019 A4 and P/2019 A7 ------------------------------------------------------------------------------------ Type Cycle GO 26 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jessica Agarwal Max Planck Institute for Solar System Y Research CoI: Dr. David Jewitt University of California - Los Angeles N CoI: Dr. Yoonyoung Kim Max Planck Institute for Solar System N Research CoI: Dr. Harold A. Weaver The Johns Hopkins University Applied N Physics Laboratory CoI: Max Mutchler Space Telescope Science Institute N CoI: Dr. Stephen M. Larson University of Arizona N ------------------------------------------------------------------------------------ Abstract We propose to study the nuclei and dust environments of the recently discovered active asteroids P/2019 A4 and P/2019 A7 at the highest possible resolution. Our primary goal is to determine the causes of the activity, specifically if driven by the sublimation of ice or caused by an instantaneous process such as an impact or rotational instability. To this purpose, we propose to characterise the nuclei, search for potential bound or unbound companions, and study the dust environment and its evolution with time. As A4 is located in the middle main belt, sublimation-driven activity, if found, would place a strong new constraint on the location of the snow line in the early solar system. A7 is located in the outer main belt and hence more likely to contain ice, but the discovery circumstances are different from those of typical main belt comets with sublimation-driven activity. Our proposed observations will help to understand this difference. We propose three 1-orbit visits to either object between 2019 April and mid-June. Given their discovery in 2019 January, we could not propose these observations at the last regular deadline for GO proposals. Waiting for Cycle 27 will mean that the dust diagnostic of the current activity will have been dispersed by solar radiation pressure. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will observe active asteroids P/2019 A4 and P/2019 A7 during 3 1-orbit visits each between 2019 April and early June. The first visit should be scheduled as soon as possible to catch the objects at the minimum possible geocentric distance (highest angular resolution). The second and third visits should be scheduled at roughly monthly intervals to study the motion of potential fragments or a binary component and to exploit the changing angles between the line of sight from Earth and the orbital planes of the objects for analysis of the dust motion. The predicted ranges of total magnitude between 2019 April and June is V = 20.7 15706( 9) - 15-Apr-2019 16:16:54 - [ 2] .. 21.7 (A4) and V = 21.5 .. 22.4 (A7). We expect that the nuclei or largest fragment will be 1-2 mag fainter, V = 22 -- 24. The orbital visibility for a solar system target near the ecliptic plane is 54 min (Section 6.3 of the HST Primer document). In each orbit, we will take 8 exposures of ~225s using the C1K1C-subarray of WFC3. We will perform a 2x2 subsampling dither box pattern, obtaining 2 exposures at each dither point. This strategy gives us a total exposure time of 1800s = 30min per orbit, and estimated overheads of 6min for guide-star acquisition, 2.6min for the first exposure, a total of 14.7min for the subsequent 7 exposures, and 1.5min for the three spacecraft maneuvers required for dithering, which adds up to a total execution time of 54min per orbit. We will use the wide bandpass filter F606W for an optimum trade-off between sensitivity and highest resolution: the bandpass (475 -- 700 nm) covers the maximum of the solar spectrum, and is in the wavelength range where the PSF is smallest (FWHM<0.07arcsec, from the WFC3 instrument handbook for Cycle 26), such that we can optimally exploit our subsampling dither strategy. The WFC3 exposure time calculator returns for a solar-spectrum point source at V=22 (24), exposure time of 225s, F606W filter, and default background values a signal-to-noise-ratio (S/N) of 80 (29) within a circle of 0.08arcsec (ETC Request IDs: WFC3UVIS.im.1312246 and WFC3UVIS.im.1312247). The small aperture is needed to separate the flux from the nucleus or fragment from that of the surrounding coma. A fragment with V=26 will be detected at S/N=8 (WFC3UVIS.im.1285906), such that we expect to detect fragments down to 180m diameter for standard assumptions on a C-type asteroid with geometric albedo p=0.06 (Nugent et al., 2016) and phase function coefficient G=0.15 (Bowell et al., 1989). The position uncertainty predicted for A4 in early April is currently of order 10 arcsec. We request a late ephemeris update option at the phase 2 stage to be able to flexibly deal with possible late updates of the ephemeris based on new astrometric measurements. The ephemeris uncertainty for A7 is small compared to the WFC3 field of view. The maximum apparent motion of the targets is only ~62 arcsec/hr (0.02 arcsec/s), which is well within Hubble's tracking capabilities. ------------------------------------------------------------------------------------ 15706( 9) - 15-Apr-2019 16:16:54 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: P2019A4-V1 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID Active asteroid ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=2.613583746324236, E=0.08960734196836118, I=13.32039689241388 , O=119.2995371407606, W=341.7814697490555, M=10.258094656676, EQUINOX=J2000, EPOCH=18-JAN-2019:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 21 +/- 0.5 Ephemeris Center: EARTH Ephemeris Uncertainty: 23000 KM Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 TARGET NAME: P2019A4-V2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID Active asteroid ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=2.613548561710995, E=0.0896028018538064, I=13.31897611728256 , O=119.3001705986976, W=341.9095170765762, M=12.716814643128, EQUINOX=J2000, EPOCH=29-JAN-2019:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 21 +/- 0.5 Ephemeris Center: EARTH Ephemeris Uncertainty: 23000. KM Extended: YES 15706( 9) - 15-Apr-2019 16:16:54 - [ 4] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 4 TARGET NAME: P2019A4-V3 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID Active asteroid ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=2.613583746324236, E=0.08960734196836118, I=13.32039689241388 , O=119.2995371407606, W=341.7814697490555, M=10.258094656676, EQUINOX=J2000, EPOCH=18-JAN-2019:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 23 +/- 0.5 Ephemeris Center: EARTH Ephemeris Uncertainty: 23000. KM Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 TARGET NAME: P2019A7 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID Active asteroid ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=3.188304552499178, E=0.1607480733255885, I=17.772656582968 , O=280.5213002812847, W=119.5461347673522, M=46.56029697759, EQUINOX=J2000, EPOCH=04-OCT-2018:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 22 +/- 0.5 Ephemeris Center: EARTH Extended: YES 15706( 9) - 15-Apr-2019 16:16:54 - [ 5] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ 15706( 9) - 15-Apr-2019 16:16:54 - [ 6] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.145 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 15706( 9) - 15-Apr-2019 16:16:54 - [ 7] Visit: 01 (A4_V1) Visit Requirements: BETWEEN 01-APR-2019:00:00:00 AND 14-APR-2019:00:00:00 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 P2019A4-V1 WFC3/UVI ACCUM UVIS2-C1K F606W 2 220 S REQ EPHEM CORR ECA4V1; S 1C-SUB (1760 S) PATTERN 1 1 Comments: The flash-warning disappears if the ETC is run with calculating the zodiacal light for the actual target position on 2019 April 01. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2019A4-V1 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none 1 none 1 N/A S K1C-SUB P2019A4-V1 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none 2 none 1 N/A S K1C-SUB P2019A4-V1 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none 1 none 1 N/A S K1C-SUB P2019A4-V1 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none 2 none 1 N/A S K1C-SUB P2019A4-V1 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none 1 none 1 N/A S K1C-SUB P2019A4-V1 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none 2 none 1 N/A S K1C-SUB P2019A4-V1 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none 1 none 1 N/A S K1C-SUB P2019A4-V1 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none 2 none 1 N/A S K1C-SUB 15706( 9) - 15-Apr-2019 16:16:54 - [ 8] Visit: 02 (A4_V2) Visit Requirements: BETWEEN 22-APR-2019:00:00:00 AND 12-MAY-2019:00:00:00; GROUP 02, 03 WITHIN 2D; ON HOLD On Hold Comments: The target ephemeris and position uncertainty need to be updated before the visit executes. 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 P2019A4-V2 WFC3/UVI ACCUM UVIS2-C1K F606W CR-SPLIT=NO 1 550 S REQ EPHEM CORR ECA4V2; S 1C-SUB (2200 S) PATTERN 1 1 Comments: The flash-warning disappears if the ETC is run with calculating the zodiacal light for the actual target position on 2019 May 01. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2019A4-V2 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none none none 1 N/A S K1C-SUB P2019A4-V2 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none none none 1 N/A S K1C-SUB P2019A4-V2 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none none none 1 N/A S K1C-SUB P2019A4-V2 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none none none 1 N/A S K1C-SUB 15706( 9) - 15-Apr-2019 16:16:54 - [ 9] Visit: 03 (A4_V3) Visit Requirements: BETWEEN 22-APR-2019:00:00:00 AND 12-MAY-2019:00:00:00; ON HOLD On Hold Comments: The target ephemeris and position uncertainty need to be updated before the visit executes. 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 P2019A4-V2 WFC3/UVI ACCUM UVIS2-C1K F606W CR-SPLIT=NO 1 550 S REQ EPHEM CORR ECA4V3; S 1C-SUB (2200 S) PATTERN 1 1 Comments: The flash-warning disappears if the ETC is run with calculating the zodiacal light for the actual target position on 2019 June 01. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2019A4-V2 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none none none 1 N/A S K1C-SUB P2019A4-V2 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none none none 1 N/A S K1C-SUB P2019A4-V2 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none none none 1 N/A S K1C-SUB P2019A4-V2 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none none none 1 N/A S K1C-SUB 15706( 9) - 15-Apr-2019 16:16:54 - [ 10] Visit: 04 (A7_V1) Visit Requirements: BETWEEN 01-APR-2019:00:00:00 AND 21-APR-2019:00:00:00 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 P2019A7 WFC3/UVI ACCUM UVIS2-C1K F606W CR-SPLIT=NO 2 220 S PATTERN 1 1 S 1C-SUB (1760 S) Comments: The flash-warning disappears if the ETC is run with calculating the zodiacal light for the actual target position on 2019 April 01. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none 2 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none 2 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none 2 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none 2 none 1 N/A S K1C-SUB 15706( 9) - 15-Apr-2019 16:16:54 - [ 11] Visit: 05 (A7_V2) Visit Requirements: BETWEEN 22-APR-2019:00:00:00 AND 09-JUN-2019:00:00:00 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 P2019A7 WFC3/UVI ACCUM UVIS2-C1K F606W CR-SPLIT=NO 2 230 S PATTERN 1 1 S 1C-SUB (1840 S) Comments: The flash-warning disappears if the ETC is run with calculating the zodiacal light for the actual target position on 2019 May 01. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none 2 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none 2 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none 2 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none 2 none 1 N/A S K1C-SUB 15706( 9) - 15-Apr-2019 16:16:54 - [ 12] Visit: 06 (A7_V3) Visit Requirements: AFTER 05 BY 0.8 Orbits TO 1.2 Orbits; BETWEEN 22-APR-2019:00:00:00 AND 09-JUN-2019:00:00:00 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 P2019A7 WFC3/UVI ACCUM UVIS2-C1K F606W CR-SPLIT=NO 2 230 S PATTERN 1 1 S 1C-SUB (1840 S) Comments: The flash-warning disappears if the ETC is run with calculating the zodiacal light for the actual target position on 2019 June 01. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 1 none 2 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 2 none 2 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 3 none 2 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none 1 none 1 N/A S K1C-SUB P2019A7 1 WFC3/UVI ACCUM UVIS2-C1 F606W 4 none 2 none 1 N/A S K1C-SUB 15706( 9) - 15-Apr-2019 16:16:54 - [ 13] Summary Form for Proposal 15706 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-C1K1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 05 BY 0.8 Orbits TO 1.2 Orbits, BETWEEN 01-APR-2019:00:00:00 AND 14-APR-2019:00:00:00, BETWEEN 01-APR-2019:00:00:00 AND 21-APR-2019:00:00:00, BETWEEN 22-APR-2019:00:00:00 AND 09-JUN-2019:00:00:00, BETWEEN 22-APR-2019:00:00:00 AND 12-MAY-2019:00:00:00, GROUP 02, 03 WITHIN 2D, ON HOLD , PATTERN 1 1, REQ EPHEM CORR ECA4V1, REQ EPHEM CORR ECA4V2, REQ EPHEM CORR ECA4V3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names P2019A4-V1, P2019A4-V2, P2019A7 ------------------------------------------------------------------------------------------------------------------------------------