18124( 4) - 25-Feb-2026 19:17:32 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18124 Version: 4 Check-in Time: 25-Feb-2026 19:17:32 STScI Edit Number: 0 Title Logos-Zoe: a triple or quadruple trans-Neptunian system? ------------------------------------------------------------------------------------ Type Cycle GO 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Audrey Thirouin Lowell Observatory Y CoI: Dr. Keith S. Noll Planetary Science Institute N CoI: Dr. Will M. Grundy Northern Arizona University N CoI: Dr. Scott Sander Sheppard Carnegie Institution of Washington N ------------------------------------------------------------------------------------ Abstract (58534) 1997 CQ29 (a.k.a Logos-Zoe) is a dynamically Cold Classical system in the trans-Neptunian belt. The primary, Logos, and its satellite, Zoe, have similar brightness inferring a nearly equal-sized binary. Based on Hubble Space Telescope (HST) images obtained since 2001, it has been noticed that both system's components have large lightcurve variabilities on very different timescales. Logos' variability is over a short-time scale of hours whereas Zoe's variability seems to be on a long-time scale of days to months. New ground-based observations obtained over five years with 4 to 6-m class telescopes have proven that this system is more complicated than initially thought. Logos is a high mass ratio contact binary with a rotational period of about 17 hours. But, despite five years of unresolved ground-based observations, the rotational period of Zoe remains unknown. The brightness variation of Zoe is consistent with a highly elongated object or even a contact binary based on HST images. We request eight non-consecutive orbits to observe the Logos-Zoe system to 1) constrain the rotational lightcurve of Zoe inferring its rotational period and shape, 2) update the mutual orbit determination, 3) model and predict the upcoming mutual events season of this highly complex system, and 4) challenge the current formation models for binary/multiple systems. The Logos-Zoe mutual event season will start in 2026 and will end in 2029 with only up to two events per year, implying that we are running out of time to characterize this system. The next mutual event season will be in 151 years, therefore, this is the only chance in our lifetimes to understand this system. ------------------------------------------------------------------------------------ Observations Description ------------------------ We aim to constrain the rotational properties (rotational period and shape) of the satellite Zoe. We will also update the mutual orbit determination to improve the mutual events season prediction. ------------------------------------------------------------------------------------ 18124( 4) - 25-Feb-2026 19:17:32 - [ 2] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: LOGOS ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID Trans-Neptunian system ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=45.42219223977799, E=0.1237573151409189, I=2.895362234339929 , O=132.5091420103192, W=337.5035420772433, M=55.68419386030521, EQUINOX=J2000, EPOCH=10-FEB-2014:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 23.5 +/- 1.0 Ephemeris Center: EARTH Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 18124( 4) - 25-Feb-2026 19:17:32 - [ 3] Visit: 01 (LogosZoe) Visit Requirements: BETWEEN 26-JAN-2026:00:00:00 AND 27-JAN-2026:00:00:00 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 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0, 0; SEQ 1-7 S 2C-SUB S) NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.0894, 0.3341 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.1785, 0.1908 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.2679, 0.5249 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.3173, 0.3591 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.4100, 0.6967 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.5024, 0.5158 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 | ------------------------------------------------------------------------------------------------------------------------------------ LOGOS 1 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 2 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 3 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 4 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 5 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 6 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 7 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB 18124( 4) - 25-Feb-2026 19:17:32 - [ 4] Visit: 02 (LogosZoe) Visit Requirements: AFTER 01 BY 26.4 H TO 40.8 H 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 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0, 0; SEQ 1-7 S 2C-SUB S) NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.0894, 0.3341 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.1785, 0.1908 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.2679, 0.5249 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.3173, 0.3591 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.4100, 0.6967 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.5024, 0.5158 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 | ------------------------------------------------------------------------------------------------------------------------------------ LOGOS 1 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 2 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 3 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 4 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 5 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 6 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 7 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB 18124( 4) - 25-Feb-2026 19:17:32 - [ 5] Visit: 03 (LogosZoe) Visit Requirements: AFTER 01 BY 48 H TO 62.4 H 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 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0, 0; SEQ 1-7 S 2C-SUB S) NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.0894, 0.3341 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.1785, 0.1908 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.2679, 0.5249 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.3173, 0.3591 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.4100, 0.6967 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.5024, 0.5158 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 | ------------------------------------------------------------------------------------------------------------------------------------ LOGOS 1 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 2 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 3 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 4 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 5 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 6 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 7 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB 18124( 4) - 25-Feb-2026 19:17:32 - [ 6] Visit: 04 (LogosZoe) Visit Requirements: BETWEEN 31-JAN-2026:14:23:00 AND 01-FEB-2026:10:00:00 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 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0, 0; SEQ 1-7 S 2C-SUB S) NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.0894, 0.3341 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.1785, 0.1908 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.2679, 0.5249 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.3173, 0.3591 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.4100, 0.6967 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.5024, 0.5158 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 | ------------------------------------------------------------------------------------------------------------------------------------ LOGOS 1 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 2 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 3 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 4 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 5 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 6 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 7 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB 18124( 4) - 25-Feb-2026 19:17:32 - [ 7] Visit: 05 (LogosZoe) Visit Requirements: BETWEEN 10-FEB-2026:00:00:00 AND 11-FEB-2026:02:41:00 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 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0, 0; SEQ 1-7 S 2C-SUB S) NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.0894, 0.3341 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.1785, 0.1908 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.2679, 0.5249 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.3173, 0.3591 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.4100, 0.6967 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.5024, 0.5158 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 | ------------------------------------------------------------------------------------------------------------------------------------ LOGOS 1 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 2 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 3 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 4 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 5 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 6 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 7 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB 18124( 4) - 25-Feb-2026 19:17:32 - [ 8] Visit: 06 (LogosZoe) Visit Requirements: BETWEEN 21-MAR-2026:00:00:00 AND 26-MAR-2026:14:00:00 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 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0, 0; SEQ 1-7 S 2C-SUB S) NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.0894, 0.3341 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.1785, 0.1908 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.2679, 0.5249 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.3173, 0.3591 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.4100, 0.6967 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.5024, 0.5158 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 | ------------------------------------------------------------------------------------------------------------------------------------ LOGOS 1 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 2 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 3 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 4 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 5 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 6 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 7 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB 18124( 4) - 25-Feb-2026 19:17:32 - [ 9] Visit: 07 (LogosZoe) Visit Requirements: ON HOLD On Hold Comments: The observing cadence will be re-worked after the first 5 visits and thus we put the following visits on hold for the moment. 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 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0, 0; SEQ 1-7 S 2C-SUB S) NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.0894, 0.3341 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.1785, 0.1908 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.2679, 0.5249 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.3173, 0.3591 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.4100, 0.6967 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.5024, 0.5158 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 | ------------------------------------------------------------------------------------------------------------------------------------ LOGOS 1 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 2 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 3 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 4 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 5 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 6 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 7 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB 18124( 4) - 25-Feb-2026 19:17:32 - [ 10] Visit: 08 (LogosZoe) Visit Requirements: ON HOLD On Hold Comments: The observing cadence will be re-worked after the first 5 visits and thus we put the following visits on hold for the moment. 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 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0, 0; SEQ 1-7 S 2C-SUB S) NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.0894, 0.3341 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.1785, 0.1908 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.2679, 0.5249 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.3173, 0.3591 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.4100, 0.6967 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LOGOS WFC3/UVI ACCUM UVIS2-C51 F350LP 1 230 S (230 POS TARG 0.5024, 0.5158 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 | ------------------------------------------------------------------------------------------------------------------------------------ LOGOS 1 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 2 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 3 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 4 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 5 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 6 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB LOGOS 7 WFC3/UVI ACCUM UVIS2-C5 F350LP none none none none 1 N/A S 12C-SUB 18124( 4) - 25-Feb-2026 19:17:32 - [ 11] Summary Form for Proposal 18124 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-C512C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 26.4 H TO 40.8 H, AFTER 01 BY 48 H TO 62.4 H, BETWEEN 10-FEB-2026:00:00:00 AND 11-FEB-2026:02:41:00, BETWEEN 21-MAR-2026:00:00:00 AND 26-MAR-2026:14:00:00, BETWEEN 26-JAN-2026:00:00:00 AND 27-JAN-2026:00:00:00, BETWEEN 31-JAN-2026:14:23:00 AND 01-FEB-2026:10:00:00, ON HOLD , POS TARG 0, 0, POS TARG 0.0894, 0.3341, POS TARG 0.1785, 0.1908, POS TARG 0.2679, 0.5249, POS TARG 0.3173, 0.3591, POS TARG 0.4100, 0.6967, POS TARG 0.5024, 0.5158, SEQ 1-7 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F350LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names LOGOS ------------------------------------------------------------------------------------------------------------------------------------