The TESS Project Office announces a new mission policy to enable rapid community follow-up of high-energy transient events occurring in TESS’s field of view while preserving TESS’s tradition of open data with no period of exclusive access.
Under this policy, the mission may extract limited but actionable information—such as sky location and brightness—for broad dissemination via the General Coordinates Network, Astronomer’s Telegram, or similar publicly accessible bulletins before TESS data become publicly available at MAST. Importantly, mission team members may not use not-yet-public data to pursue scientific analyses or follow-up observations until TESS data are publicly available. This approach follows standard data processing and archiving procedures while providing critical time-sensitive information to the time-domain astrophysics community.
This policy will be invoked only for extraordinary transient events of broad scientific interest where TESS provides unique or timely information relevant for planning follow-up observations. For example, the optical counterparts of GRB 230307A and GRB 241030A were brighter than 16th magnitude, and TESS’s 200-second cadence images captured the relevant sky locations before, during, and after the triggers.
Under the newly adopted policy, actionable information can reach the scientific community 12-48 hours sooner than the standard public data release timeline.