NASA's TESS reveals 'lightest' exoplanet ever with a year lasting around 8 hours

Adding to the list of strangest exoplanets ever found, astronomers have discovered a new one which is the lightest and possibly the hottest one ever. Dubbed GJ 367b, the exoplanet is located 31 light-years away from our sun and orbits a small red dwarf star in just 7.7 hours, which means that one year on this planet is shorter than a full day here on Earth. Besides, the rocky planet also has several mind-bending features as it is just 70% the size of Earth and is nearly half as massive which makes it the lightest planet ever discovered, the researchers report in their study published on December 2 in Science.

Astronomer Kristine Wei Fun, co-author of the study said as per Space.Com, "We already know a few of these, but their origins are currently unknown. By measuring the precise fundamental properties of the USP (ultra-short period) planet, we can get a glimpse of the system's formation and evolution history".

TESS marks another significant discovery

Researchers from the German Aerospace Center's (DLR) Institute of Planetary Research referred data from NASA's Transiting Exoplanet Survey Satellite (TESS) which was launched in 2018 to hunt for exoplanets. The technique this satellite uses for tracing exoplanets around a star is called the "transit method", where it detects the dip in light emerging from a star whenever a planet crosses through its face.

Scientists confirmed the ultra-short period feature of planet GJ 367b after they noted a dip in the light emerging from the red dwarf the exoplanet is orbiting. Owing to its closeness to the red dwarf, planet GJ 367b endures extreme temperatures on its surface despite the star being small and dim. The surface temperature on this exoplanet reaches a massive 1,500 degrees Celsius (2,732 degrees Fahrenheit) during the day and creates an environment that can melt even the metals. Although the origin of this planet is unknown, findings suggest that 86% of the planet's interior is heavily rich in iron.

"The high density indicates the planet is dominated by an iron core. These properties are similar to those of Mercury, with its disproportionately large iron and nickel core that differentiates it from other terrestrial bodies in the solar system",  co-lead author Szilárd Csizmadia said in a report as per Space.com. Meanwhile, the exoplanet will continue to be an interesting subject for the scientists who believe that studying it and its star might shed light on new planets and explain their origins.

Image: Twitter/DLR_de