We often hear that like Earth, there are many planets (exoplanets) in the Galaxy. The first exoplanet was discovered in 1992, with the help of the recently retired Kepler Space Telescope. Since then, the astronomers have discovered hundreds of exoplanets. Interestingly, in June 2019, the 4,000th exoplanet was confirmed by NASA. And now, the Hubble Space Telescope spotted an exoplanet shaped like an American football, reported Mashable India. The exoplanet is named as WASP-121b.
According to the observations of Hubble Space Telescope, WASP-121b is orbiting dangerously closer to the star that’s hotter than our sun. It is worth mentioning here that this is the first time when the observations reveal elements heavier than hydrogen and helium escape from a hot Jupiter.
The observations of Hubble Space Telescope further revealed that WASP-121b is orbiting so close to the star that its upper atmosphere has reached a blazing hot temperature of 4600 degrees Fahrenheit.
Lead researcher David Sing said, “Heavy metals have been seen in other hot Jupiters before, but only in the lower atmosphere. So you don't know if they are escaping or not. With WASP-121b, we see magnesium and iron gas so far away from the planet that they're not gravitationally bound.”
Researchers further pointed out that hot Jupiters are mostly made up of hydrogen, and since Hubble is very sensitive to hydrogen, it’s relatively easier for these planets to lose the gas. However, in the case of WASP-121b, the hydrogen and helium gas is outflowing and drags these metals with them, which makes for an efficient mechanism for mass loss.
Notably, WASP-121b study is a part of the Panchromatic Comparative Exoplanet Treasury (PanCET Survey) which is basically a Hubble program that looks over 20 exoplanets that range in size from Super Earths to Jupiter. The observations surrounding WASP-121b helps with delving deeper into how planets lose their primordial atmospheres.