TESS Below we provide a brief summary of the DRN for each Sector in TESS Cycle 1.
Sector 13
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 18 | 34 33 |
2019-06-19 -- 2019-07-03 2019-07-04 -- 2019-07-17 |
307051 -- 316969 317638 -- 327529 |
0.93 | 27.51 | Every 3.375 days Every 3.375 days |
list | Issue | Description |
| Star tracker anomaly: | There was a single upset in the star trackers on the spacecraft bus. This resulted in a complicated interaction between the instrument quaternions and attitude control system. This interaction caused the spacecraft to fall out of fine pointing for approximately 1.25 hours from TJD 1665.2983 to 1665.350. During this time, the spacecraft exhibited increased pointing jitter - see page 3 of the DRN for more information. |
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| Spacecraft pointing: | Due to the proximity of the Moon to the boresight of Camera 1, guiding with Camera 1 was disabled and Camera 4 alone was used for guiding in all of orbit 33. In Orbit 34, both Camera 1 and Camera 4 were used for guiding for the entire duration of the orbit. |
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| Scattered light: | In Sector 13, the main stray light features are caused by the Moon and Earth in the first three quarters of each orbit. | ||||||
Sector 12
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 36 | 31 32 |
2019-05-21 -- 2019-06-04 2019-06-05 -- 2019-06-18 |
286196 -- 296309 297056 -- 306314 |
1.04 | 26.90 | Every 3.125 days Every 3.125 days |
list | Issue | Description |
| Spacecraft pointing: | Due to scattered light from the Earth Camera 1 was disabled and Camera 4 alone was used for guiding in all of orbit 31. This configuration causes the apparent pointing of Cameras 1, 2 and 3 to drift by larger amounts than in other sectors due to differential velocity aberration. The amplitude of the drift depends on each camera, and has a maximum value of 3 arc-seconds (0.14 pixels) in Camera 1 from the beginning to end of orbit 31. In orbit 32, both Camera 1 and Camera 4 were used for guiding for the entire duration of the orbit. |
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| Scattered light: | In Sector 12, the main stray light features are caused by the Earth and Moon at the start of each orbit. | ||||||
Sector 11
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 16 | 29 30 |
2019-04-23 -- 2019-05-06 2019-05-07 -- 2019-05-20 |
265908 -- 275212 275991 -- 285434 |
1.08 | 26.04 | Every 3.125 days Every 3.125 days |
list | Issue | Description |
| 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 29 on 2019-04-26 UTC (Cadence # 268190), and orbit 30 on 2019-05-10 UTC (Cadence # 278455) |
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| Spacecraft 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, and attitude control was done using only inputs from Camera 4. When Camera 1 guiding was re-enabled, the spacecraft attitude shifted by a small amount, about 1 arc-second (0.05 pixels) |
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| Scattered light: | In Sector 11, the main stray light features are caused by the Earth at the start of each orbit. | ||||||
Sector 10
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 14 | 27 28 |
2019-03-26 - 2019-04-08 2019-04-09 -- 2019-04-22 |
246223 -- 255117 255821 -- 265122 |
>0.98 | 25.27 | Every 3.125 days Every 3.125 days |
list | Issue | Description |
| 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 27 on 2019-03-28 UTC (Cadence # 247263), and orbit 28 on 2019-04-11 UTC (Cadence # 257233) |
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| Spacecraft 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, and attitude control was done using only inputs from Camera 4. When Camera 1 guiding was re-enabled, the spacecraft attitude shifted by a small amount, about 1 arc-second (0.05 pixels). | ||||||
| Scattered light: | In Sector 10, the main stray light features are caused by the Earth at the start of each orbit. | ||||||
| Big Updates! | In sector 10, a new linearity model is used in pixel calibration. The differences between new and old linearity model are quite small over the majority of the dynamic range of the CCDs, rising to ∼ 1 − 2% near pixel saturation. This new linearity model will be applied to all sector data from Sector 10 on, and it will be applied to data from Sectors 1-9 when those data are reprocessed. |
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Sector 9
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 11 | 25 26 |
2019-02-28 -- 2019-03-13 2019-03-14 -- 2019-03-25 |
227348 -- 236222 237073 -- 245534 |
1.18 | 24.08 | Every 3.125 days Every 3.125 days |
list | Issue | Description |
| 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 25 on 2019-03-01 UTC (Cadence # 227733), and orbit 28 on 2019-03-14 UTC (Cadence # 237273) |
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| 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, and attitude control was done using only inputs from Camera 4. When Camera 1 guiding was re-enabled, the spacecraft attitude shifted by a small amount, about 1 arc-second (0.05 pixels). | ||||||
| Scattered light: | In Sector 9, the main stray light features are caused by the Earth at the start of each orbit, and the Moon in Camera 1 in the first five days of orbit 26. | ||||||
Sector 8
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 10 | 23 24 |
2019-02-02 -- 2019-02-14 2019-02-15 -- 2019-02-27 |
208718 -- 217159 218018 -- 226472 |
1.19 | 20.22 | Every 3.125 days Every 3.125 days |
list | 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) |
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| 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. |
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| Big Updates: | 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 7
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 9 | 21 22 |
2019-01-08 -- 2019-01-19 2019-01-21 -- 2019-02-01 |
190203 -- 198420 199615 -- 207814 |
1.66 | 22.80 | Every 3.125 day Every 3.125 day |
list | Issue | Description |
| Scattered light: | In Sector 7, the main stray light features are caused by the Earth and Moon rising above the sunshade at the end of orbit 21, which continues through the start of orbit 22. | ||||||
| Back level residuals: | Some channels show a small non-zero residual in the mean black level after calibration that is either static (e.g., camera 3, CCD 2, output D) or slowly time varying (e.g., camera 4, CCD 1, all outputs and camera 4, CCD 3, all outputs). The level of these residuals is minor i.e., ∼ 1e-3 ADU/read and the timescale of variation is of order 5–10 days. These residuals are thought to be caused by the jitter of bright stars on the specific CCD slices, and therefore it is a persistent effect in the rest of the sectors. The impact of these residuals on scientific output is likely negligible. However, the Sector 7 data were calibrated using the updated 1-D black method, from which we do not expect such time-varying residuals. | ||||||
| Big Updates! | As of Sector 7, the spacecraft clock kernel has been updated. The estimated accuracy of the TJD values in all products associated with this data release is 50 ms. | ||||||
Sector 6
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 8 | 19 20 |
2018-12-12 -- 2018-12-24 2018-12-25 -- 2019-01-06 |
171185 -- 179687 180468 -- 189064 |
1.09 | 20.68 | Every 3.125 days Every 3.125 days |
list | Issue | Description |
| Data collection: | The first ∼3 days (start 2018-12-15 UTC) of orbit 19 were used to collect calibration data for measuring the pixel-response function of the cameras under the improved pointing system. | ||||||
| Scattered light: | In Sector 6, the main stray light features are caused by the Earth rising above the sunshade at the end of orbit 19, which continues through the start of orbit 20. | ||||||
| TJD Calculation | The clock kernel used to calculate TJD in Sector 6 used ranging data collected only through late August, 2018; as a result, the extrapolation to Sector 6 times is slightly off. The error between true and calculated times grew linearly with time since August 2018, so that the calculated TJD values in all data products are offset from the correct values by ∼2.0 seconds at the end of orbit 20 (2019-01-06 UTC). See pg. 7 of the DRN for more information. | ||||||
Sector 5
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 7 | 17 18 |
2018-11-15 -- 2018-11-27 2018-11-29 -- 2018-12-11 |
151467 -- 160375 161347 -- 170601 |
1.35 | 25.23 | Every 3.0 days Every 3.0 days |
list | Issue | Description |
| Guiding: | The use of Camera 1 in attitude control was disabled for the last ∼ 0.5 days of orbit 18 (2018-12-11 UTC, cadence #170269) due to strong scattered light signals, and data taken with Camera 1 during this period were excluded from the pipeline analysis. |
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| Space craft pointing: | At the end of orbit 18, the Earth was < 35◦ from the boresight of Camera 1. At these low angles, the level of scattered light is too high for meaningful guide star centroids to be measured - see Guiding issue above. Disabling Camera 1 guiding near the end of the Sector caused a brief impulse in pointing, which settled out within minutes. | ||||||
| Scattered light: | In Sector 5, the main stray light features are caused by the Earth rising above the sunshade at the end of each orbit, and strong glints appear during these times. The Earth moves quite close to the boresight of Camera 1 at the end of orbit 18. | ||||||
| TJD Calculation | The clock kernel used to calculate TJD in Sector 5 used ranging data collected only through late August, 2018; as a result, the extrapolation to Sector 5 times is slightly off. The error between true and calculated times grew linearly with time since August 2018, so that the calculated TJD values in all data products are offset from the correct values by ∼1.7 seconds at the end of orbit 18 (2018-12-11 UTC). See pg. 7 of the DRN for more information. | ||||||
| Big Updates! | Starting with Sector 5 processing, the SPOC pipeline 1-D Black correction has been changed to a two-component model from the polynomial fit that had been used prior. The two components include: a time-varying correction and a static row-by- row correction. To learn more about this see pg. 8 and 9 of the DRN. | ||||||
Sector 4
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|
|---|---|---|---|---|---|---|---|---|
| 5 | 15 16 |
2018-10-19 -- 2018-11-01 2018-11-02 -- 2018-11-14 |
132081 -- 141159 141908 -- 150764 |
1.04 | 22.23 | Every 2.5 days Every 2.5 days |
list | Issue | Description |
| Incorrect guide star table | An incorrect table was into the DHU at the beginning of Sector 4. The spacecraft pointing was offset by ∼4 arc-seconds from where it would have pointed had the correct guide star table been loaded. Thus, once the correct guide star table was loaded (TJD 1413.26), the spacecraft pointing shifted by ∼4 arc-seconds. | |||||||
| Instrument reset: | At TJD 1418.54, an interruption in communications between the instrument and space- craft occurred, resulting in an instrument turn-off until TJD 1421.21. 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. | |||||||
| Spacecraft pointing: | Sector 4 was the first set of science observations with an improved Attitude Control System (ACS) algorithm. The new ACS mode displays significantly lower pointing jitter than the previous configuration. | |||||||
| Scattered light: | In Sector 4, the main stray light feature are caused by the Earth rising above the sunshade at the end of each orbit. The Earth reaches a minimum of 35 degrees from the center of Camera 1, and strong glints appear between TJD 1422.2297 and 1423.5020 (orbit 15) and between TJD 1436.1047 and 1436.8353 (orbit 16). | |||||||
| Timing precision and accuracy: | The clock kernel used to process Sector 4 data has a slight error, resulting from extrapolation of timing measurements made during Sector 1. The reported TJD values in all data products are therefore offset by ∼1.6 seconds at the end of orbit 16 (2018-11-14 UTC). | |||||||
Sector 3
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 4 | 13 14 |
2018-09-20 -- 2018-10-03 2018-10-05 -- 2018-10-17 |
111297 -- 120978 121788 -- 130988 |
1.12 | 20.4 | Every 2.5 days Every 2.5 days |
list | Issue | Description |
| Spacecraft pointing: | During sector 3 there were several experiments conducted on the attitude control system (ACS) to improve pointing stability. Tests were conducted during the perigee passages after orbits 12, 13 and 14, as well as the first 3 days of orbit 13 and the last 3 days of orbit 14. During these times, the ACS feedback loop was altered and the calibration parameters tuned. The jitter profile during these times differs substantially from the normal data collection mode, which used the same ACS configuration as in Sectors 1 and 2. Imaging and light curve data during these tests is provided for completeness, but has limited use for scientific applications. Valid data in the standard ACS configuration were collected between TJD 1385.8966 and 1395.4800 in orbit 13 and between TJD 1396.6050 and 1406.2925 in orbit 14, spanning ∼20.4 days of useful observations. | ||||||
| Scattered light: | In Sector 3, the main stray light feature is caused by the Earth rising above the sunshade near the end of each orbit, resulting in an enhancement of the stray light over parts of each camera’s FOV. | ||||||
| Timing precision and accuracy: | The clock kernel used to process Sector 3 data has a slight error, resulting from extrapolation of timing measurements made during Sector 1. The reported TJD values in all data products are therefore offset by ∼1.2 seconds at the end of orbit 14 (2018-10-17 UTC). | ||||||
Sector 2
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 2 | 11 12 |
2018-08-23 -- 2018-09-05 2018-09-07 -- 2018-09-20 |
91186 -- 100583 101620 -- 110922 |
1.44 | 27.4 | Every 2.5 days Every 2.5 days |
list | Issue | Description |
| Scattered light: | In Sector 2, the main stray light features to be aware of are: The upturns at the end of each orbit are caused by the Earth rising above the sunshade, which reaches a minimum of ∼50 degrees from the center of Camera 1. The Earth’s daily rotation is evident in the background level. The lower level rise in the first orbit of Camera 1 (days 4–9) is caused by the Moon moving within 30 degrees of the camera boresight. | ||||||
Sector 1
Information
| DRN | Orbits | Dates (UTC) Start - End |
Cadence # Start - End |
Data pause (days) |
Science data (days) | Momentum dumps | Problematic TIC ID's |
|---|---|---|---|---|---|---|---|
| 1 | 9 10 |
2018-07-25 -- 2018-08-08 2018-08-09 -- 2018-08-22 |
70444 -- 79968 80782 -- 90519 |
1.13 | 27.9 | Every 2.5 days Every 2.5 days |
list | Issue | Description |
| Scattered light: | In Sector 1, the main stray light features to be aware of are: There is an oscillation in the background with a period of 1 day caused by the rotation of the Earth. The Moon gets quite close to the FOV of Camera 1 at the end of the sector. On the last day of observations, the angle between the Moon and the boresight of Camera 1 is <30◦ , which causes a the large spike. | ||||||
| Mars: | Mars was near opposition during Sector 1 and landed in the field-of-view of Camera 1 for ∼2 days at the beginning of observations. Specifically, it is in Camera 1, CCD 4, output channel D, and visual inspection of the FFIs and target pixel files shows an extremely bright object with excess charge spread across the pixels in this output channel. As a consequence, photometry is unreliable in this section of the CCD in the first ∼510 cadences of the sector. See pgs. 7 and 8 of the DRN for more information. | ||||||
| Timing precision and accuracy: | Due to an error in the spacecraft clock kernel, the two-minute cadence durations vary by ∼0.51 msec and the FFI durations vary by ∼7.8 msec. The changes in the durations are discontinuous and occur at reference points used to interpolate the conversion from space- craft time to TJD. However, these errors are well within TESS’s 1 second timing accuracy requirement. | ||||||