The discovery of a Neptune- sized planet around a hot, bright star could help astronomers understand the mysterious lack of Neptune-sized worlds in tight orbits, a phenomenon known as the Hot Neptune Desert.


Now, astronomers at the University of California, Berkley, say they’ve found a rare Neptune-sized planet orbiting a giant A-type star.

The exoplanet, known as HD 56414 b, is 873 lightyears away in the constellation of Volans.

More discoveries like this could help astronomers better understand why there are few known Neptune-sized planets orbiting close to their host star.

Though current detection methods mean most exoplanets we know of are close to their stars and larger than Jupiter, including so-called hot Jupiters, it’s thought that if a small world gets too close to a star, the radiation will strip its atmosphere away.

To test this, Courtney Dressing from the University of California, Berkeley looked for Neptune-sized worlds around A-type stars, which are much brighter in ultraviolet than other types of star.

"If we’re able to look at planets receiving different amounts of light from their star, especially different wavelengths of light, then we can try to see how exactly a planet keeps its atmosphere over time," says Dressing.



Elizabeth Pearson
Ezzy PearsonScience journalist

Ezzy Pearson is the Features Editor of BBC Sky at Night Magazine. Her first book about the history of robotic planetary landers is out now from The History Press.