Disappeared exoplanet turned out to be a cloud of dust

Astronomers from the University of Arizona found that the telescope “Hubble” 12 years watched the cloud of dust that nearly all that time was considered an exoplanet.

Planet Dagon, also known as Fomalhaut b, was discovered in October 2008 at the very edge of the dust disk surrounding the remote 25 light-years from the Sun star Fomalhaut. Once, in 2011, scientists questioned the existence of Dagon, but then he was still identified as a planet.

However, ambiguities remained. Dagon was too bright and showed no signs of infrared radiation, which is very unusual extrasolar planets do not have enough size to reflect such a large amount of light and at the same time they are warm, that is, should be visible in the infrared range.

After gathering and analyzing all available historical information of Hubble about Dagon, the Arizona astronomers came to the conclusion that it is still not a planet and a cloud of dust formed from the collision of two objects of about 200 km each. And the main proof of this version is that in 2014, the Dagon just disappeared, and scientists believe that the disappearance was the result of the dispersion of a dust cloud — now its size is about 200 million kilometers.

But this discovery did not upset the astronomers, the exoplanet is because they received a witness a rare event — such as collision in the system of Fomalhaut occur about once in 200,000 years. And “Hubble” at the right time in the right place, giving scientists the opportunity to observe how the planet can destroy each other. The only disappointment is that the telescope did not record the moment of collision.