NASA Discovers TOI-3261 b: A Hot Neptune with a 21-Hour Year

NASA scientists have made a groundbreaking discovery with the identification of an exoplanet named TOI-3261 b, where a year lasts just 21 Earth hours. This ultra-hot planet is comparable in size to Neptune and orbits its star at an exceptionally close distance, leading to its remarkably brief orbital period. TOI-3261 b is only the fourth known exoplanet of its kind, and researchers believe it could provide valuable insights into the formation of such planets.

Discovery was facilitated by NASA’s Transiting Exoplanet Survey Satellite

The discovery was facilitated by NASA’s Transiting Exoplanet Survey Satellite (TESS), with additional observations conducted using ground-based telescopes in Australia, Chile, and South Africa. Measurements indicate that TOI-3261 b belongs to a rare category known as “hot Neptunes,” characterized by their smaller size, proximity to their host star, and short orbital periods. With a year lasting just 21 hours, TOI-3261 b joins an exclusive group of ultra-short-period hot Neptunes, which includes only three other known members.

Through advanced modeling techniques, the scientific team has reconstructed the 6.5 billion-year history of the TOI-3261 star and planet system. Their findings suggest that TOI-3261 b may have originally formed as a massive gas giant, potentially similar to Jupiter, but has undergone significant changes over time. The planet likely lost a substantial amount of mass due to two primary processes: photoevaporation, where stellar energy disperses gas particles, and tidal stripping, where the gravitational pull of the star removes layers of gas from the planet.

Alternatively, researchers propose that TOI-3261 b may have formed at a greater distance from its star, where the effects of photoevaporation and tidal stripping would have been less severe, potentially allowing it to retain a more substantial atmosphere.

One of the most intriguing features of TOI-3261 b is its remaining atmosphere, which will be the focus of further analysis. Notably, the planet has a density that is twice that of Neptune, suggesting that its atmosphere has been stripped of lighter elements over time, leaving behind only heavier components. This indicates that the planet’s atmosphere may have once contained a diverse array of elements, although its exact composition is still unknown.

To uncover this mystery, astronomers plan to observe TOI-3261 b in infrared light, potentially utilizing NASA’s James Webb Space Telescope. This approach aims to identify the distinctive molecular fingerprints in the planet’s atmosphere, which could illuminate not only the history of TOI-3261 b but also the fundamental physical processes that govern all hot, giant planets.