Date

Slides & Recording

Attendees

Agenda 

  • News & Announcements
  • TSO upcoming observations + TTRB highlights
  • NIRSpec timestamp work by Alicia Lloyd (Elena Manjavacas' Intern)
  • Roundtable check-ins 
  • Closing remarks

Discussion items

TimeItemWhoNotes
2 minNews & AnnouncementsAll
8 min  TSO upcoming observations + TTRB highlightsCarter
  • range of recent TSOs – from low-mass planets to brown dwarfs! 
10 min

NIRSpec timestamp work by Alicia Lloyd (Elena Manjavacas' Intern)

Lloyd


  • all uncalibrated NIRSpec TSO data is showing timestamp differences between NRS1 & NRS2 (issue identified in Sept 2024) 
  • In March 2025, ASIC synchronization applied helps the issue!
  • project design:
    • used BOTS data from 96 unique programs, pulling out start/end times from uncle file headers (correlated times with Nints, Ngroups, filter, grating, SCTARRATE  (spacecraft time adjustment)
    • plotted time differences against obs duration & performed linear fits 
  • Alicia sees 1) timestamp difference slopes that increase, decrease, or remain constant
  • post-March 2025:
    • NRS1 is ahead of NRS2, then hey exactly sync up, then NRS2 is ahead of NRS1 (~3/5 way through the observations) 
    • 50% are constant, 15% increasing, 35% decreasing 
  • for all timestamp difference slopes, the observations span a range of Nints, Ngroups, obs durations
  • constant slopes = largely have 1) higher number of groups, 2) lower number of integrations, and 3) <6 hr observation durations
  • no correlation between any given date and how the timestamp differences behave
  • largest timestamp differences are ~10 seconds, typical differences post-ASIC sync are ~0.04 seconds
  • Taylor Bell asks how the timestamp differences compare for repeat observations of the same target with the same setup
    • for Luhman 16, currently see similar slopes of two visits - there will be a third visit (to add another data point to see if this holds up)
    • Nestor Espinoza took a look at the science side of the differences - for exoplanet science, the differences are ok and not a hinder to science 
  • Munazza Alam asks about the cases in which the difference drifts and NRS1/2 switch – likely due to different ticking times for the clocks 
  • Katie Bechtold shows that TA strategy affects the period between telemetry samples, so there is something interesting on board happening that is affecting these timestamps (some quantized beat frequency pattern, with a numeric precision lower than that)
  • Elena Manjavacas checked the script for converting the onboard timestamps to the science header timestamps, could be a source of the error on this (1e-7 MJD =  0.00864 seconds)
  • Hannah Diamond-Lowe asks which is the "correct" time? → since there are so many corrections applied to the times, it's hard to say which is right
  • Katie Bechtold asks if a micrometeoroid strikes during one of these observations, could that help us? HGA moves also cause big jumps 


10 min

Roundtable check-ins 

All


  • NIRSpec:
  • NIRISS:
    • Aarynn Carter mentions that multistripe cals need to be defined for cal program 
  • NIRCam:
    • Brian Brooks mentions that multistripe ETC changes in the works, updates for the next pipeline builds
    • Achrene Dyrek reports a min of 10 DHS submitted proposals in C5 (compared to 4 submitted, 2 accepted in C4)
      • need to push forward the TSO calibration program of WASP-18b (timeline: late spring to late summer) - other cal targets: HAT-P-16b, HAT-P-34b
        • need to submit APT file for this! (need to check WFC3 observability for simultaneous observations)   
  • MIRI:
    • Hannah Diamond-Lowe mentions that investigations for MRS multistripe will begin (if successful, should also work for LRS) 
5 minClosing remarks All 

Timestamp Presentation 

Action items

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