Sector 20



× Warning for Sector 20: The FFI timestamps have been adjusted by ~0.5 seconds due to staggered readouts. The assigned timestamps of the previously released data products are too large by 2 seconds, the Sector 20 data products have been updated and have accurate timestamps. The photometric apertures for targets with Tmag less than 11 were slightly increased. This change most noticeably affects the light curves of saturated stars, which had higher flux losses during periods of increased pointing jitter using the smaller apertures

Sector 20 Information

For full data release notes see: DRN27. For a list of TIC IDs with noted issues, see this list.

Updates:

  • In Sector 20, the the FFI timestamps have been adjusted for the 0.5 second staggered readouts of the four cameras and the 0.02 second staggered readouts for individual CCDs within a camera.
  • The assigned timestamps of the previously released data products are too large by 2 seconds. The issue was caused by an off-by-one error in ground system software that identifies the timestamps of individual two second exposures. The Sector 20 data products have been updated and have accurate timestamps
  • The start times of integrations for every 2 minute and 30 minute cadence were shifted forward by 31 milliseconds, and the end times were shifted forward by 11 milliseconds. These offsets correct for effects in the focal plane electronics that were not accounted for in previous data releases.
  • Until sectors 1-19 are re-processed, the adjustments mentioned above should be applied to the FFI image headers.
  • Two-minute data products report the TJD at mid-exposure, and so should be corrected by adding 21 milliseconds to the timestamps.
  • Note that the correction only applies to the timestamps themselves.
  • In Sector 20, the photometric apertures for targets with Tmag < 11 were slightly increased. This change most noticeably affects the light curves of saturated stars, which had higher flux losses during periods of increased pointing jitter using the smaller apertures.

    • Sector Summary

  • Sector dates: December 24 2019 to January 20 2020
  • Pointing: Northern hemispher
  • Days of Science Data Collection: 24.79
  • Days of Paused Data Collection: 1.53



    • Spacecraft Pointing (deg)

    RA dec roll
    Spacecraft 129.39 75.25 334.57
    Camera 1 110.05 40.33 81.75
    Camera 2 117.67 63.91 75.61
    Camera 3 182.33 83.58 192.29
    Camera 4 270.0 66.56 105.95



    Orbit Summary

    Orbits Dates (UTC)

    Start - End

    		 Cadence #

    Start - End

    		 Momentum dumps
    47 2019-12-24 - 2020-01-06 442831 - 451729 Every 5.35 days
    48 2020-01-07 - 2020-01-20 452833 - 461784 Every 5.5 days



    Sector Notes

    Noted Issue Description
    Instrument reset An instrument reset occurred in orbit 48—no data were collected for two minutes between TJD 1865.49753 and 1865.50030.
    Spacecraft pointing Camera 1 and Camera 4 were both used for guiding in orbit 47; Camera 4 alone was used for guiding in orbit 48.
    Scattered light In Sector 20, the Moon passes through the field of view of Camera 1 at the start of orbit 48, saturating the detectors. In Sector 20, new data anomaly flags were added to characterize the different ways that the scattered light can affect the data - see section 2 of the DRN.