The planet lies in an area known as the Neptunian Desert, which is the name given to the region immediately surrounding a star where planets of similar size to Neptune are nearly never found. Here, most bodies disintegrate and lose their atmospheres, but not NGTS-4b.
The planet was identified by an global team of astronomers using the Next-Generation Transit Survey telescopes (NGTS) at the European Southern Observatory's Paranal facility in the Atacama Desert, Chile.
The team aren't completely sure why The Forbidden Planet has managed to keep its atmosphere.
NGTS-4b was detected by scientists with the European Southern Observatory. It is a collaboration between UK Universities Warwick, Leicester, Cambridge, and Queen's University Belfast, together with Observatoire de Genève, DLR Berlin and Universidad de Chile. n the search for planets in other stellar systems, the is part of Paranal's arsenal of telescopes.
"This planet must be tough - it is right in the zone where we expected Neptune-sized planets could not survive", lead author Richard West, an astronomer at the University of Warwick in the United Kingdom, said in a statement.
When searching for new planets, astronomers look for a dip in the light of a star-this the planet orbiting it and blocking the light. Known as Hot Neptunian Deserts, these rings of intense irradiation and heat are found right across the Universe - but they may not be as inhospitable as we once thought. A study detailing the planet published Monday in the journal Monthly Notices of the Royal Astronomical Society.
Discovered using the state-of-the-art Next-Generation Transit Survey (NGTS) observing facility, created to search for transiting planets on bright stars, but NGTS-4b is so small other ground surveys wouldn't have spotted it.
The researchers suspect that NGTS-4b may have only recently moved into the Neptunian Desert, perhaps over the last million years. Yet, it still has its own atmosphere, something that has caused researchers to scratch their heads.
Searches from the ground can usually pick up when a star dims by 1 percent or more, but using the Next Generation Transit Survey for 272 straight nights, astronomers have now picked up the smallest blip yet: a transit depth of just 0.13 percent.
Richard West, a professor in the department of physics at the University of Warwick who worked on the research, called the discovery "truly remarkable" in a press release. "Perhaps the desert is greener than was once thought".
The findings of the global study are featured in the journal Monthly Notices of the Royal Astronomical Society.