Fomalhaut b is a myth. Or more precisely, a huge dust cloud.

Fomalhaut b has been shrouded in tumult for years. In 2011, there were questioned the existence of the exoplanet, to be brought back to life a year later. But now, remarkably, Fomalhaut b has completely disappeared from view. Although Fomalhaut b was one of the first exoplanets photographed by astronomers, researchers now argue that this planet probably never existed.

Fomalhaut b
Fomalhaut b was discovered in 2008 from images taken by the Hubble space telescope in 2004 and 2006. The planet was clearly visible during multiple Hubble observations that revealed it as a moving dot around the bright star Fomalhaut about 25 light-years from Earth. soil. This made the planet, along with the discovery of three planets around HR 8799 – the discovery of which was announced the same day – the first exoplanet to be confirmed by direct images. However, discussion soon broke out. For example, Fomalhaut b was too far from its star, and the orbit around the star could not be calculated. But the biggest counter-argument was that heat could not be measured due to the lack of infrared radiation. The photos taken of the planet could be put straight into the trash. Although Fomalhaut b was written off as a measurement error, scientists later returned to this conclusion. Fomalhaut b is said to be an exoplanet. And not just any, but a rare and perhaps even a very unique one.

Planet … or not?
However, the subject did not let go of researchers. And so they again analyzed images from Hubble, this time from 2014. Surprisingly, Fomalhaut b was nowhere to be seen, much to the disbelief of the astronomers. However, previous images had already shown that the object continued to fade over time. “It was clear that Fomalhaut b did things that a full-fledged planet shouldn’t do,” said researcher András Gáspár.

Dust cloud
The non-detection forced the astronomers to a new conclusion. And this says that Fomalhaut b is not a planet at all. What Hubble did photograph? The new interpretation is that Fomalhaut b is a slowly expanding cloud of dust blown into space as a result of a major collision between two large celestial bodies. These colliding objects may have consisted of a mixture of ice and dust, such as the comets that reside in the Kuiper Belt, on the edge of our solar system. The icy, comet-like objects may have been about 200 kilometers each. The researchers believe that the disastrous collision did not take place too long before the first observations of Fomalhaut b in 2004, so that Hubble’s space telescope caught its aftermath. The resulting debris cloud consisted of dust particles of 1 micron (or 1/50 of the diameter of a human hair).

Images of the expanding dust cloud observed by the Hubble space telescope between 2004 and 2013.. The cloud was created by a collision between two large celestial bodies orbiting the bright nearby star Fomalhaut. It is the first time that such a catastrophic event around another star has been visualized.

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Rare
It is very special that the aftermath of the collision was captured on image. Because it is the first time that such a catastrophic event around another star has been visualized. “These kinds of collisions are extremely rare,” explains Gáspár. For example, it is thought that such events in the Fomalhaut system occur only once every 200,000 years. “It is very special that we have seen this. We were in the right place at the right time to witness such an unlikely event. ”

The authors state that their new theory explains all observed characteristics of Fomalhaut b. And with that the stocking is finished. In the future, astronomers will continue to observe the Fomalhaut system with the upcoming James Webb telescope. For example, they want to map the inner warm areas of the system directly. The team will also hunt for – this time really existing – planets orbiting Formalhaut that may be waiting to be discovered. But we still have to be patient for that. NASA said recently work on the James Webb telescope by suspending the coronavirus outbreak. It would initially take to the skies in 2021. It means that the launch of the space telescope is once again delayed. But there will be no delay. In any case, the space telescope will take to the skies and will likely attempt to solve many of the prevailing mysteries – including that of the Fomalhaut system.