Observations of Comet 3I/Atlas
Observations of TESS Sector 99 will be interrupted for 7 days (15-22 January 2026) for observations of the interstellar comet 3I/Atlas. These observations will be designated Sector 1751 and Orbit 30721 (these arcane numbers are useful for POC bookkeeping purposes). The data collected during these observations will be limited to full-frame images (FFIs) and a mosaic of pixels surrounding the path of 3I/Atlas at 20s and 2m cadence. These data will be calibrated in the standard fashion and posted to MAST promptly.
Nominal observations of Sector 99 will be performed from January 5 to January 15, 2026, and resume again on January 22 and continue through February 2, 2026.
Pointing
The orientation of the spacecraft and camera boresights during Sector 1751 are given in the table below.
| Boresight | RA | Dec | Roll | Ecliptic Longitude | Ecliptic Latitude |
|---|---|---|---|---|---|
| Spacecraft | 109.492 | 21.842 | 84.336 | 108.0 | -0.4 |
| Camera 1 | 146.623 | 14.309 | 162.411 | 144.0 | 0.8 |
| Camera 2 | 122.225 | 20.174 | 169.754 | 120.0 | 0.0 |
| Camera 3 | 96.549 | 22.518 | -0.760 | 96.0 | -0.8 |
| Camera 4 | 70.763 | 20.784 | 8.896 | 72.1 | -1.5 |
| All coordinates are degrees (J2000) | |||||
