Every week, telescopes around the world detectnew exoplanets orbiting stars other than the Sun. But the last one found by the United Kingdom InfraRed Telescope (known by the acronym UKIRT), 3.8 meters in diameter and located in Hawaii, is out of the ordinary: al being very bloated, the new planet “defies conventional models of planetary evolutionand supports the hypothesis that this type of celestial objects could have been formed in a radically different way from those of the Solar System “, as explained by Eduardo Martín, researcher at the CSIC Astrobiology Center and co-author of the work published in the journalMonthly Notices of the Royal Astronomical Society.
Current theories predict that the radii of newly formed planets decrease over time as they radiate their internal energy. However, considering thatthe discovered exoplanet – baptized as WTS-1b – and its progenitor star formed 600 million years ago, the body should be 20% larger than Jupiter and not 50%, as seen. One possible explanation is the closeness between WTS-1b and its star, whichmakes the exoplanet not cool so quickly and remains “inflated”.
The star WTS-1 is located in the disk of the Milky Way, about 10,400 light years distant from Earth, making WTS-1b one of the 15 farthest known exoplanets. Its radius is 15% greater than that of the Sun and its temperature – approximately 6,250 degrees Kelvin – is greater than that of the Sun. The use of spectroscopic techniques has revealed thatthe exoplanet is a “hot Jupiter” type gaseous bodyWith a mass similar to Jupiter, it is in a much tighter orbit than Mercury’s (about ten times closer), so the amount of energy received from the star is considerable. The radius of the exoplanet is 1.5 times that of Jupiter, and its mass is four times greater.
WTS-1b has been detected by an international team of scientists, which includes the Astrobiology Center, the National Distance Education University, the Canary Islands Astrophysics Institute, the German-Hispanic Astronomical Center, the University of La Laguna, and numerous European and Latin American institutions. For this purpose, the UKIRT telescope and its WFCAM camera have been used mainly, within the framework of a project dedicated to detecting planets around M stars in the infrared using infrared photometry techniques to identify transits.
