The pitch-black night skies of Great Barrier Island look set to become a magnet for star-gazers after being recognised with a rare award.

The island, also known as Aotea, is the third place in the world to be named an International Dark Sky Sanctuary.

Island residents Richard and Gendie Somerville-Ryan assisted with the application to the International Dark Sky Association and are delighted at the outcome.

"Chuffed is probably a mild word," says Mr Somerville-Ryan

"We're completely over the moon, if you'll excuse the bad pun.

"We need to share it," says Mrs Somerville-Ryan.

"We've got Aucklanders sitting here who have never seen a night's sky like we have on the Barrier, to say nothing of the international visitors."

She says the skies are dark on Great Barrier Island because the lack of mains power restricts the amount of light that's generated.

"We don't have outdoor lights, we're very parsimonious with indoor lights even. People carry torches to get around. It's a different way of living off the grid."

Mr Somerville-Ryan says about 5000 stars are visible on a clear night on Great Barrier Island, about 10 times as many as can be seen in Auckland.

The team submitted scientific readings of the darkness on Great Barrier Island.

Great Barrier Local Board Chair, Izzy Fordham, says the measurements showed what residents of the island had long suspected – that the skies were as perfect as possible.

"Sanctuary status is reserved for the most isolated, and dark locations in the word and this designation is specifically designed to increase awareness of fragile sites and promote their long-term conservation," she says.

The only other place in New Zealand recognised by the International Dark Sky Association is the Mackenzie Basin, in the centre of the South Island.

It was designated as a Dark Sky Reserve in 2012, and is now one of 11 places to carry that status.

'Reserve' means the region boasts exceptionally starry skies, which are specifically protected by local planning regulations.