× Sector 8 was reprocessed in May 2021, updating the background correction, manual exclude flags, timestamps, and input catalog. For more deatil please see the Reprocessing Information table below.

× Warning for Sector 8: At TJD 1531.74, an interruption in communications between the instrument and spacecraft occurred, resulting in the instrument being turned off and a loss of ~3 days of data.

Sector 8 Information

For full data release notes see: DRN10, DRN42 (reprocessing). For a list of TIC IDs with noted issues, see this list.

Update: The algorithm in the CAL module that removes the 1D bias from raw pixel data was changed. The 1D bias estimate is now split into two components, a time-dependent scalar correction and a static row-dependent correction.

Sector Summary

Sector dates: February 2 to February 27 2019

Pointing: Southern hemisphere

Days of Science Data Collection: 20.22

Days of Paused Data Collection: 1.19

Spacecraft Pointing (deg)

	RA	dec	roll
Spacecraft	128.12	-37.74	155.31
Camera 1	142.37	-4.18	250.66
Camera 2	133.69	-26.7	248.3
Camera 3	120.6	-48.42	60.15
Camera 4	90.0	-66.56	33.85

Orbit Summary

Pointing	Spacecraft RA, dec	Spacecraft roll (deg)
Southern hemisphere	128.12, -37.74	155.31

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Sector Notes

Orbits	Dates (UTC) Start - End	Cadence # Start - End	Momentum dumps
23	2019-02-02 - 2019-02-14	208718 - 217159	Every 3.125 days
24	2019-02-15 - 2019-02-27	218018 - 226472	Every 3.125 days

Noted Issue	Description
Instrument reset	At TJD 1531.74, an interruption in communications between the instrument and spacecraft occurred, resulting in an instrument turn-off until TJD 1535.00. No data or telemetry were collected during this period. After the instrument anomaly the heaters were turned on, increasing the camera temperature by ∼ 20◦ to approximately −67◦ C. Once the camera power was restored, the heaters were turned off and the camera temperatures returned to nominal within three days. The temperature increase caused changes in the camera focal plane scale and mean black levels of individual CCD channels. The mean black levels are calibrated out in the SPOC pipeline. Changes in focal plane temperature cause changes in the raw photometry, but the PDC systematic error-correction algorithm removes this effect for most targets.
Guiding	The use of Camera 1 in attitude control was disabled at the start of both orbits due to strong scattered light signals. Camera 1 guiding was enabled in orbit 23 on 2019-02-02 UTC (Cadence # 208757), and orbit 24 on 2019-02-15 UTC (Cadence # 218154)
Space Craft Pointing	At the start of each orbit, the Earth was close to the boresight of Camera 1, and the level of scattered light was too high for meaningful guide star centroids to be measured. Guiding with Camera 1 was therefore disabled at these times. When Camera 1 guiding was re-enabled, the spacecraft attitude shifted by a small amount, about 1 arc-second (0.05 pixels). These times are marked with Attitude Tweak flags in the data products.
Scattered Light	In Sector 8, the main stray light features are caused by the Earth at the start of each orbit, and the Moon in Camera 1 towards the start of orbit 24. The algorithm in the CAL module that removes the 1D bias from raw pixel data was changed. The 1D bias estimate is now split into two components, a time-dependent scalar correction and a static row-dependent correction.

Reprocessing Information: DRN42

During TESS’s primary mission several updates were made to various instrument models, algorithms, and pipeline parameters. Below we list what was updated and applied when reprocessing sectors 1-13. Please see DRN42 for a more comprehensive explanation of each update.

Update	Description
Instrument models updated:	Electronics model Reference Flux, PRF, and Linearity
Calibration Pipeline Module updates:	The 1D bias estimate is now split into two components, a time-dependent scalar correction and a static row-dependent correction. The first two overclock rows were also removed. The propagation of the uncertainty from the 2D bias model was changed. It is a static term and no longer applied to pixel data.
Pre-Search Data Conditioning Pipeline Module updates:	The parameters to calibrate the PDC goodness metrics were finalized.
Transiting Planet Search Pipeline Module updates:	An initial run of TPS is now used to identify problematic epochs that are assigned “deemphasis weights” in a second and final run of TPS.
Compute Optimal Aperture Pipeline Module updates:	The photometric apertures for stars with Tmag less than 11 were slightly increased.
Photometric Analysis Pipeline Module updates:	The sky background estimate was modified. A scalar offset is now applied that forces the dimmest background-corrected pixels to values near zero, if those pixels were significantly negative.
TESS Input Catalog update:	Targets were reprocessed with version 8 of the TIC. The change affected the apertures assigned to individual targets and the calculations for crowding (CROWDSAP) and flux fraction (FLUXFRAC), and as such the physical properties of TCEs derived from stellar parameters.
Timestamps update:	Timestamps were updated to account for previous drift errors and electronic effects. All data from Sectors 1–36 are now registered to a consistent time system.
New data flags:	All flags are now consistent with those described in DRN30.
Threshold Crossing Event issues:	The planet search of the reprocessed light curves produced a different set of TCEs from the original processed data. There is a high degree of overlap, but not every TCE from previous data releases was recovered. To differentiate between the initial release and this reprocessed data a "pipeline instance number" is included in the filenames of the dv-timeseries, dv-reports, ad dv-result xml files. Larger pin numbers indicate later versions of the software were used to produce the data products. The DR number is also included as a keyword in the export product headers (DATA_REL).