The images taken by the Hubble telescope showed that the planet Dagon – a giant object on a disk of gas and dust, discovered in 2004, actually never existed. The discovery was initially questioned – until now, none of the scientists have been able to make out a huge planet, which should revolve around the star Fomalhaut, located relatively close to the Earth, only 25 light-years away.
Fomalhaut, Dagon? What is it?
Both of these objects have not only strange names but also an ambiguous story. Fomalhaut is a young star and one of the brightest in the night sky. It is located in the constellation Southern fish.
This is one of the first stars discovered by people – the first confirmed certificate of the star is dated about 2500 BC. e. Archaeologists have discovered that at that time the star “participated” in the rituals conducted by the peoples inhabiting the territory of Persia.
Fomalhaut is considered a young star – her age is estimated at 200-300 million years. For comparison, the age of the Sun is 4.6 billion years. Its mass is 1.3 times greater than the mass of our star, and the luminosity of Fomalhaut is 16 times higher than that of the Sun.
Astronomers suspected the existence of a planet orbiting Fomalhaut, back in 1998 – then scientists calculated the trajectory along which it can rotate.
In 2004-2006, the Hubble telescope during a survey of the area in which the star is located noticed a bright point near it – Fomalhaut b, or Dagon.
The planet, as astronomers then believed, was located near a dense disk of gas and dust surrounding a star. The discovery was added to the fame that seeing a distant planet directly is a rarity. In 2008, after some doubts, NASA issued a press release in which it announced the discovery of the planet by the star Fomalhaut.
What exactly did Hubble see?
Dagon is a Semitic deity associated with shipping and agriculture. The planet got this name due to its gigantic size – analysis of images taken by the telescope showed that its mass is three times the mass of Jupiter. Further measurements corrected its mass to the range from Martian to terrestrial.
The exoplanet has a very elongated orbit – a complete revolution around Fomalhaut takes from 872 to 1700 years. In 2015, the International Astronomical Union named two more planets that orbit around the star along with Dagon – Fomalhaut b and Fomalhaut s. It is because of them that the exoplanet has such a strange orbit, scientists believed.
But a second analysis conducted in April 2020 by astronomers from the University of Arizona showed that Dagon does not exist – nor its neighboring planets.
In their study, scientists reanalyzed the data collected by the Hubble telescope in 2004–2006 and 2010–2014. The study showed that the planet behaves very strangely.
Firstly, in 2014, Dagon disappeared from almost all the photos, although in previous years the object was fixed constantly. Its size increased every year – while the planet was losing its brightness until it disappeared completely in 2014.
Further analysis showed that the speed of the object increased sharply compared to 2004, and the direction of movement diverged greatly from the estimated orbit. All these features are contrary to what scientists know about planets.
This behavior is explained by the fact that Dagon is not really a planet, but a dust ring, which arose as a result of the collision of two very large asteroids or planetary nuclei.
The collision, scientists suggest, occurred in 2004 – just when Hubble began to observe the surroundings of Fomalhaut. Over time, the dust began to disperse – this explains the increase in the size of the object and the decrease in its brightness.
The same can explain the strange trajectory of the object. All this indicates that in fact Dagon never existed, the authors of the study say.
The nature of Dagon has always raised great doubts, if only because Fomalhaut himself is too young. Its age does not exceed several million years, and it is still surrounded by a dense circumstellar disk of gas, ice, and dust. If full-fledged planets have already formed here, they should still be red-hot and actively emit in the infrared range. However, Dagon, clearly visible in rays, in the infrared, is invisible, although it emits unusually a lot of ultraviolet light. Therefore, the discovery of scientists is not so surprising as it seems at first glance.