A giant exoplanet leaves its tail behind

Researchers are currently excited about a celestial phenomenon whose evaporating atmosphere turns into the tail of an exoplanet.

FRANKFURT – Researchers are now marveling at a real phenomenon in the sky, because the massive exoplanet WASP-69b orbits so closely around a star that its atmosphere is evaporating and can be seen as a tail in the sky, like a comet. Previous research indicated that the exoplanet had a rather weak tail. “However, we have now conclusively detected this tail and shown that it is at least seven times longer than the planet itself,” says Dakota Tyler, a doctoral student at the University of California, Los Angeles (UCLA) and lead author of the study. Trade magazine Astrophysical Journal Has been published.

Researchers have noticed a rare event in the sky: an exoplanet tracking its tail

Despite its impressive length, exoplanet WASP-69b itself is as large as Jupiter – the largest planet in our solar system. After its discovery about ten years ago, it became known as “Hot Jupiter.” It is a huge gas planet. according to University of California announcement The exoplanet is so close to its star that its orbit takes less than four days. The planet closest to the sun in our solar system – Mercury – takes 88 days to complete its orbit, or about 22 times longer.

Evaporating atmosphere becomes exoplanet's tail: 'WASP-69b is a gem'

We already know that most planets orbit their star at a much closer distance than our solar system, says Eric Petigura, co-author and professor of physics and astronomy at the University of California, California. The erosion of their atmosphere plays a major role in explaining the different types of planets. Exoplanets can vary greatly from one another, with some planets being denser than steel and others more like cotton candy.

For most known exoplanets, the loss of atmosphere is presumed to have been completed long ago. This is what makes the discovery of the exoplanet's tail so interesting to research. “WASP-69b is a gem because we have a rare opportunity to study atmospheric mass loss in real time and understand the critical physics that forms thousands of other planets,” Petigura says.

The tail of an exoplanet is visible, a rare opportunity for research

Hydrogen and helium in particular are said to evaporate from the exoplanet's atmosphere. Radiation and gas flow from its star, so-called stellar winds, form over hundreds of thousands of kilometres. The tail forms “when the planet's escaping atmosphere encounters stellar winds, causing the gas to be blown back,” Petigura explains. The exoplanet WASP-69b can be observed using the James Webb Telescope, which provides new insights into the universe.