A team of researchers, including scientists from the University of Tokyo, has discovered a rare type of planet known as TOI-1355 b. This planet orbits a star called TOI-1355 in an unusual, highly elliptical path—meaning its orbit is stretched into an oval shape rather than a perfect circle. TOI-1355 is much hotter than our Sun, with a surface temperature of 8,400°C (15,100°F), compared to the Sun’s 5,500°C (9,900°F). TOI-1355 b, classified as a "hot Jupiter"—a type of gas giant planet that orbits very close to its star—completes one orbit around its host star in about two Earth days. The discovery was made using data from NASA's Transiting Exoplanet Survey Satellite (TESS), which monitors stars for periodic dimming. This dimming occurs when a planet passes in front of the star from Earth's perspective, an event known as a planetary transit. By analyzing the changes in the brightness of the star and the planet, the researchers were able to determine the planet's mass and the eccentricity of its orbit. The elliptical orbit of TOI-1355 b is of particular interest to scientists. Such an orbit may have formed due to gravitational interactions with other planets or celestial bodies in the system. Over time, tidal forces from the host star may have caused the planet’s orbit to shrink and become more circular. However, the dynamic nature of the orbit means that TOI-1355 b will eventually move out of view from Earth, and it is expected to no longer be observable after around 2033. The research team, led by Project Researcher Noriharu Watanabe and Professor Norio Narita from the University of Tokyo, plans to conduct further studies on the planet’s orbital inclination and how it relates to the star’s rotation. They also intend to propose observations using NASA’s James Webb Space Telescope, which is designed to study distant planets and their atmospheres in greater detail. The findings from this study have been published in the journal Publications of the Astronomical Society of Japan, contributing to our growing understanding of planetary systems beyond our own.