TESS Observations

TESS observes the sky in sectors measuring 24° x 96°.  Each sector is observed for two orbits of the satellite around the Earth, or about 27 days on average. The field-of-view is oriented along a line of ecliptic longitude with the instrument boresight generally pointing at ±54° ecliptic latitude, which centers Camera 4 on an ecliptic pole.  By orienting the fields in this way, a 24° diameter region centered on the ecliptic pole can be observed for nearly a full year. During certain sectors in Year 2, the instrument boresight will be pointed at +85° to avoid excessive scattered light in cameras 1 and 2. Because the fields-of-view are shifted north along a line of ecliptic longitude, the region near the ecliptic pole is still observed continuously.

During Year 1 of the mission (July 2018-July 2019), the southern ecliptic hemisphere was observed. During Year 2 of the mission (July 2019-July 2020), the northern hemisphere is being observed. During Year 3 of the mission, the southern ecliptic hemisphere will be re-observed. Details of the observations during the first three years of the mission, including spacecraft pointings, can be found at these links:  Year 1, Year 2, Year 3.

The timing of TESS observations and ground contacts can be found in the TESS Operations Calendar.

Observations of Two-Minute Cadence Targets To Date

The images below are plots of all targets observed at two-minute cadence to date: at left, in celestial coordinates, and at right, in ecliptic coordinates. The dots are color-coded to indicate the number of times each target was observed.

Year 1

Observations during Year 1 comprised Sectors 1-13. For each of these sectors, the instrument boresight was pointed at an ecliptic declination of -54°.

Year 2

Observations during Year 2 comprised Sectors 14-26. During Year 2, the northern ecliptic hemisphere was observed. During sectors 17-23, the instrument boresight will be pointed at +54° ecliptic latitude. During Sectors 14-16 and 24-26, the boresight was/will be pointed at +85° ecliptic latitude, due to excessive contamination by stray Earth- and moonlight in cameras 1 and 2 in the nominal +54° orientation.

Year 3

Observations during Year 3 comprised Sectors 27-40. During Year 3, the southern ecliptic hemisphere will be re-observed.  For each of these sectors, the instrument boresight will be pointed at an ecliptic declination of -54°.