Exoplanet TOI-1355 b will become unobservable by 2033

An international team of researchers, including members from the University of Tokyo, has identified a rare and unusual exoplanet known as TOI-1355 b. Classified as a ‘hot Jupiter,’ the giant planet orbits its host star, TOI-1355, at an incredible speed, completing a full orbit in approximately two Earth days.

The host star is significantly hotter than the Sun, reaching temperatures of 8,400°C. TOI-1355 b follows a peculiar elliptical orbit that is currently precessing. This orbital precession is causing the planet’s path across the face of its star to shift toward the stellar limb.

Due to this change in viewing geometry, astronomers estimate that the planet will no longer be observable via transit from Earth after approximately 2033. While the planet remains in its system, the alignment required for Earth-based observations is expected to remain unavailable for hundreds of years following this period. The findings are based on data collected between 2019 and 2024 using NASA’s Transiting Exoplanet Survey Satellite and various ground-based observatories.