One Of The First And Closest Exoplanets Might Really Be Something Even More Interesting

 Fomalhaut b was one of all the primary planets reported orbiting another star, after being directly imaged using the Hubble Space Telescope. A decade later, its disappearance has cast doubt on its existence, and two scientists argue Hubble actually picked up something much rarer – the aftermath of a catastrophic collision between two objects within the gray zone between asteroids and comets.

Today, databases of exoplanets (those orbiting other stars) have thousands of entries, but a bit over a decade ago, the numbers were sparse, known from tiny wobbles their gravity-induced within the star they circled.

Fomalhaut b was something different, the primary cause of an exoplanet detected directly from the light within the visible part of the spectrum, about we thought when it had been announced in 2008. Fomalhaut is way hotter than the Sun and much too young to support advanced life. Nevertheless, the invention was exciting both because it suggested a replacement thanks to finding exoplanets was possible and since Fomalhaut is among the brightest stars within the sky. Anyone not living an extended way north of the equator could walk outside, even in a part with quite polluted skies, and say, “There could be a planet around that star.” it absolutely was considered so significant, it had been one in every of the few exoplanets given a political candidate name, Dagon, after a Middle-Eastern god.

Except, Dr. Andras Gaspar of the University of Arizona says there's not a planet. Doubts arose as astronomers struggled to search out similar objects around other stars. There just don't seem to be other samples of exoplanets this bright at wavelengths humans can see. Infrared telescopes can't find Fomalhaut b, despite operating at wavelengths at which planets are usually more visible, and it also doesn't appear to be gravitationally affecting the system's mighty dust ring.

Fomalhaut has nicknamed the attention of Sauron for obvious reasons. The image on the left shows the dust ring as seen when the star itself is masked bent prevents its light from outshining everything else. On the correct, are the pictures taken by Hubble because the debris from the supposed collision dispersed and faded. NASA, ESA, A. Gáspár and G. Rieke/University of Arizona

In Proceedings of the National Academy of Sciences, Gaspar and Professor George Rieke report that when Hubble photographed Fomalhaut again in 2014, there was no sign of a planetary companion. Intervening images show the thing fading but also growing larger.

"Our study, which analyzed all available archival Hubble data on Fomalhaut, revealed several characteristics that together paint an image that the planet-sized object may never have existed within the first place," Gaspar said during a statement. 

Instead, the authors think two super-comets around 200 kilometers (125 miles) across collided shortly before Hubble took its first images, producing a cloud of debris lit up by the brilliant light from the young star. (An object half this size hitting a far larger one is additionally possible). we all know when our Sun was the same age, the scheme was a dangerous place, with impacts that might have looked like this one. Nevertheless, the authors expect events like this to happen once every 200,000 years in an exceedingly system of this age, making catching the aftermath an interesting piece of luck.

"The Fomalhaut star system is that the ultimate test lab for all of our ideas about how exoplanets and star systems evolve," Rieke said. At just 25 light-years away, it offers us one in all our greatest opportunities to look at planetary system information.

The James Webb Space Telescope, if it finally launches successfully, has Fomalhaut on its priority observation list. With much greater power than Hubble, it should be able to check if Gaspar and Rieke's theory and models are correct.