In a recent breakthrough, astronomers have unveiled the existence of a unique exoplanet, nearly double the size of Earth and enveloped by vast oceans. This intriguing celestial body, designated as TOI-733b, adds to the ever-expanding catalog of over 5,000 known exoplanets, a journey that began in the 1990s.
Situated 245 light-years from Earth, TOI-733b was discovered by the keen eyes of NASA’s TESS telescope. It circles a star resembling our own Sun, completing an orbit in a mere 4.9 days. This proximity and similarity offer a rich opportunity to deepen our understanding of how planets form and evolve in the cosmos.
TOI-733b stands out due to its peculiar size. It exists in a rarely populated size range among exoplanets, larger than the so-called super-Earths and smaller than mini-Neptunes. This intermediate size reveals much about the mysterious ‘radius valley’ – a gap in the typical sizes of exoplanets. NASA’s scientists theorize that this gap might signify the remnants of Neptune-like planets, whose atmospheres were stripped away, leaving behind bare cores.
Led by Iskra Georgieva from Chalmers University of Technology in Sweden, a team of astronomers is particularly thrilled about what TOI-733b can reveal. Their research, soon to be published in Astronomy & Astrophysics and currently available on arXiv, focuses on unraveling the secrets of planets within this elusive radius valley.
Initial studies indicate that TOI-733b might have lost its original atmosphere or could be an aquatic world. Its proximity to its host star suggests a gradual depletion of its atmosphere, possibly transforming it into a rocky planet. Alternative theories propose the loss of lighter elements like hydrogen and helium, potentially leading to a water vapor-dominated atmosphere or a secondary atmosphere composed of heavier elements.
This discovery is not just a single addition to the exoplanet roster but a potential key to understanding planet formation and evolution. As astronomers continue their research, aided by advanced technologies, TOI-733b stands as a beacon in our quest to decipher the mysteries of the universe.