It is a giant like Jupiter, but ten times lighter: it is one of the least dense alien planets known, so much so that astrophysicists have called it the planet of “cotton candy”. It is a giant like Jupiter, but ten times lighter: it is one of the least dense alien planets known, so much so that astrophysicists have called it the planet of “cotton candy”. Spotted at a distance of 212 light years, the planet demonstrates for the first time that gas planets form more easily than expected.
The result, published in the Astronomical Journal, is due to the international group coordinated by Caroline Piaulet, of the Canadian University of Montréal. The discovery “has great implications because it addresses the fundamental issue of the formation of giant planets can form,” notes astrophysicist Björn Benneke, of the University of Montreal.
The planet is called Wasp-107b and was identified in 2017 around a star in the constellation Virgo, but now, thanks to data from the Keck Observatory in Hawaii, its mass has been accurately assessed. It was found that its mass is ten times smaller than that of Jupiter. According to astronomers with such a low density, the planet must have a solid core equal to no more than four times the mass of the Earth and this surprised astronomers who wondered how it could have formed.
Planets form in the disk of dust and gas that surrounds a young star. According to the models of the formation of gaseous planets, built on Jupiter and Saturn, the solid core must be at least 10 times larger than the mass of the Earth for a large amount of gas to accumulate around it. Wasp-107b, on the other hand, according to astronomers, would have formed very far from the star. In regions far from the star, in fact, the gas in the disk is quite cold and this allows it to accumulate faster around the core, explained one of the authors, Eve Lee, of Canadian McGill University.
“The planet subsequently – he added – was able to migrate to its current position, both through interactions with the disk and with other planets in the system”. In fact, the planet is now very close to its star, over 16 times closer than the Earth to the Sun. ten times lighter: it is one of the least dense alien planets known, so much so that astrophysicists have called it the planet of “cotton candy”. Spotted at a distance of 212 light years, the planet demonstrates for the first time that gas planets form more easily than expected. The result, published in the Astronomical Journal, is due to the international group coordinated by Caroline Piaulet, of the Canadian University of Montréal.
The discovery “has great implications because it addresses the fundamental issue of the formation of giant planets can form,” notes astrophysicist Björn Benneke, of the University of Montreal. The planet is called Wasp-107b and was identified in 2017 around a star in the constellation Virgo, but now, thanks to data from the Keck Observatory in Hawaii, its mass has been accurately assessed. It was found that its mass is ten times smaller than that of Jupiter.
According to astronomers with such a low density, the planet must have a solid core equal to no more than four times the mass of the Earth and this surprised astronomers who wondered how it could have formed. Planets form in the disk of dust and gas that surrounds a young star. According to the models of the formation of gaseous planets, built on Jupiter and Saturn, the solid core must be at least 10 times larger than the mass of the Earth for a large amount of gas to accumulate around it. Wasp-107b, on the other hand, according to astronomers, would have formed very far from the star.
In regions far from the star, in fact, the gas in the disk is quite cold and this allows it to accumulate faster around the core, explained one of the authors, Eve Lee, of Canadian McGill University. “The planet subsequently – he added – was able to migrate to its current position, both through interactions with the disk and with other planets in the system”. The planet is now very close to its star, over 16 times closer than the Earth to the Sun.
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