Researchers have recovered seven years of observations of dwarf-planet candidate 2026 ED₁₃₈ from NASA’s TESS archive. An October 29, 2026, preprint reports detections in five observing sectors spanning 2019–2026, including four recorded before the object’s discovery.
The team used archived full-frame images, removed modeled starlight, and combined exposures along the object’s predicted path. The result adds earlier positions for a distant solar-system body to data originally collected by an exoplanet mission.
Why an Exoplanet Telescope Recorded the Object
NASA’s Transiting Exoplanet Survey Satellite, or TESS, searches for planets by measuring changes in stellar brightness. A planet crossing in front of its host star blocks a small fraction of the star’s light, producing a recurring dip.
That observing method involves repeated images of large star fields. The images also contain objects within the solar system that happen to cross those fields. New Space Economy’s explanation of the TESS mission describes the transit survey that produces this record.
“Precovery” means identifying an object in observations taken before its discovery. Once an orbit supplies a predicted position at an earlier date, researchers can examine archived images for a corresponding detection.
Removing Stars to Recover a Moving Object
For this study, researchers used Gaia’s star catalog to model the crowded background and subtract its contribution. They then removed remaining static signals and stacked images along the predicted trajectory.
Stacking aligns the moving target across exposures, combining its faint signal. The analysis detected 2026 ED₁₃₈ in every sector and produced eight positions for an orbit fit.
An Independent Orbital Record
The orbit calculated from TESS agrees with the Jet Propulsion Laboratory solution, with larger uncertainties. The study reports this as an independent use of the archival measurements.
The finding follows directly from the way TESS observes: repeated exposures preserve information about both its stellar targets and moving objects within the same field. The archive supplied a multiyear observational record of 2026 ED₁₃₈ that already existed when the candidate became a named discovery.
