0 Assigned ID: 6110 ----- Attempting Submission 1 (Sat Apr 05 19:16:45 GMT 2025) ----- HST Phase I Proposal 6110 successfully submitted. Receipt: # 6110-1 ----- Attempting Submission 2 (Wed Apr 09 14:25:30 GMT 2025) ----- HST Phase I Proposal 6110 successfully submitted. Receipt: # 6110-2 I am scheduling the sixth orbit of this program. The window is from 21-MAR-2026:00:00:00 to 26-MAR-2026:14:00:00 279285605 ----- Attempting Submission 1 (Tue Aug 12 19:09:44 GMT 2025) ----- ----- Attempting Submission 2 (Wed Aug 13 18:58:07 GMT 2025) ----- ----- Attempting Submission 3 (Wed Feb 25 14:35:14 GMT 2026) ----- Visit planner ran Logos-Zoe: a triple or quadruple trans-Neptunian system? (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. 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. Our team is composed of experts in small body sciences. Dr. Audrey Thirouin and Dr. Scott S. Sheppard have expertise in data acquisition and data reduction for rotational and physical properties of trans-Neptunian objects and other small bodies in our Solar System with ground- and space-based telescopes. Dr. Keith S. Noll and Dr. William M. Grundy are experts in HST data reduction and analysis. They have been using HST over the past 25 years to search and characterize moons around trans-Neptunian objects, as well as Trojans and other small bodies. Team members have regularly used HST for binary discovery, mutual orbit determination, and characterization. Our team has an established collaboration and will work together on all aspects of the proposed investigation. Solar System Astronomy 6 false false false false false false false SUPPORTED SOLAR SYSTEM NO ASTEROID Trans-Neptunian system 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 EARTH WFC3/UVIS Imaging No No F350LP Timing link suitability includes constraints ([02 After 01 by 1.1 to 1.7 days] [03 After 01 by 2.0 to 2.6 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. 1769443664000 270.00766717212446 (Tic-Visit :proposal-id 18124 :visit-id "01" :proposal-version -1 :trans-version "20250624" :date "30-Jul-2025 09:53:37.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 32048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18124 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18124 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2211 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2619 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([02 After 01 by 1.1 to 1.7 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. 1769562248000 270.008028809229 (Tic-Visit :proposal-id 18124 :visit-id "02" :proposal-version -1 :trans-version "20250624" :date "26-Jul-2025 14:23:21.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 32048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18124 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18124 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2211 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2619 :pcs-gap 0 ) true 1 0 Timing link suitability includes constraints ([03 After 01 by 2.0 to 2.6 days]) The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. 1769641677000 270.008291597097 (Tic-Visit :proposal-id 18124 :visit-id "03" :proposal-version -1 :trans-version "20250624" :date "30-Jul-2025 09:37:42.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 32048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18124 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18124 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2211 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2619 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. 1769873292000 270.00915943589746 (Tic-Visit :proposal-id 18124 :visit-id "04" :proposal-version -1 :trans-version "20250624" :date "30-Jul-2025 09:52:52.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 32048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18124 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18124 :visit-id "04" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2211 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2619 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. 1770736753000 285.3877297678337 (Tic-Visit :proposal-id 18124 :visit-id "05" :proposal-version -1 :trans-version "20250624" :date "30-Jul-2025 10:50:10.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 32048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18124 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18124 :visit-id "05" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2211 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2619 :pcs-gap 0 ) true 1 0 Using ephemeris for target 18124-06-LOGOS ephemeris data for target 18124-06-LOGOS does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 25.360 to 27.120. ephemeris interval: 26.031 to 28.032 The scheduling data was generated by CASM 34.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18124 :visit-id "06" :proposal-version -1 :trans-version "20250624" :date "30-Jul-2025 11:46:17.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 32048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18124 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18124 :visit-id "06" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2211 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2619 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18124 :visit-id "07" :proposal-version -1 :trans-version "20250624" :date "30-Jul-2025 11:46:28.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 32048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18124 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18124 :visit-id "07" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2211 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2619 :pcs-gap 0 ) true 1 0 The observing cadence will be re-worked after the first 5 visits and thus we put the following visits on hold for the moment. The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18124 :visit-id "08" :proposal-version -1 :trans-version "20250624" :date "30-Jul-2025 11:46:37.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 32048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18124 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18124 :visit-id "08" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2211 :al-overhead-at-end 0 :internal-dur-at-end 72 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2619 :pcs-gap 0 ) true 1 0 The observing cadence will be re-worked after the first 5 visits and thus we put the following visits on hold for the moment.