This page keeps track of tilt events observed on TSO datasets. We identify CANDIDATE tilt events from TSOs based on different metrics (flux variations, FWHM, etc.) and change those to CONFIRMED based on WFS analyses/feedback.

Relevant information before reading the table below:

  • What is a "tilt" event? Read the description for TSO'ers in JDox.
  • Can I report a "tilt" event in public data that is not in the list below? Yes, please! Reach out to Nestor Espinoza if you find one and he'll tabulate it below.
  • Can I report a "tilt" event of my propietary data? Yes, that would be fantastic. However, we need direct consent from the PI(s) of the program to tabulate it below. If you have a reference (e.g., a published paper), even better. Please reach out to Nestor Espinoza if you find one and he'll tabulate it below.


DateTargetPID / ObsInstrument(s) used for detectionDetection methodStatusComments
2022-05-02Transit of HAT-P-14b1442 / 1NIRcam SW/LW + FGS

Flux "jump" (in NIRCam and FGS), FWHM "jump", centroid "jump"


See Schlawin+2022. Event at about 2459701.94 JD. Event identified to be on C6 and C1 segments.
2022-06-08Transit of HAT-P-14b1541 / 1NIRISS/SOSSFlux "bumps" (both in Order 1 and 2), FWHM


This seems to be a different tilt event flavor, with a trend in the FWHM rather than a jump in it. Various analyses done by Nestor Espinoza. It doesn't appear on FGS telemetry flux count.

2022-06-21Transit of WASP-96b2734 / 2NIRISS/SOSS (+ FGS?)FWHM "jump", but no apparent impact on white-light photometry.


This event didn't produce a measurable flux "bump", but it shows a clear FWHM "jump" signature. FGS shows what appears to be a small (500 ppm) flux jump at 2459751.86 JD — but the BJD TDB time for the event in SOSS is about 2459751.88 — so a 30-min difference.

2022-07-30Transit of WASP-39b1366 / 3NIRSpec/BOTS G395H + FGSFlux "jump", FWHM "jump", centroid "jump".


2022-08-11Eclipse of WASP-18b1366 / 21NIRISS/SOSS + FGSFlux "jump", FWHM "jump", centroid "jump".


Tilt event seems to be very small, suggesting (again) SOSS is very sensitive to these. FWHM jump is obvious in the data. Event likely on B6 segment.
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