I step out the door of Guirdil bothy at 2am to the guttural roar of a stag and the sound of the ocean lapping on the beach before me. It’s the height of the rut here on Rum, a Hebridean island where red deer outnumber people, and stags have been bolving all night.

The skull of an old, beached minke whale lies on the pebbles, just discernible in the darkness, while the imposing slopes of Bloodstone Hill tower over Guirdil, sheltering the bay from the wind and isolating it from the world. I can make out the silhouette of a stag as it strolls slowly off the beach and trots up the ridge. Wild goats follow.

Rum recently became the second site in Europe to be awarded International Dark Sky Sanctuary status (the other being Ynys Enlli in Gwynedd, north Wales), recognising the island as having one of the clearest night skies in the world. It’s hoped it will boost off-season tourism – and I’ve come to stargaze and explore. Staring into the darkness I remember what Steven Gray – the president of the British Association of Planetaria, who helped the community with their application – told me the week before: that your eyes take 20 minutes to adapt to the dark.

I choose a comfy-looking rock and sit down and wait. I had watched the sun set over the isle of Canna, a few miles across the water, shortly after arriving at Guirdil. Now I’m willing the clouds to part above it for a glimpse of the celestial wonders.

Today, over 99% of people in Europe live under light-polluted skies. But in Scotland there are still some really, really dark skies. Rum is particularly special. Only 40 people live here year-round and 97% of the island is a nature reserve (Kinloch, the sole settlement, entered community ownership in 2009). Light pollution is near nonexistent. There are no street lights and you need a permit to drive a car – not that it would get you far. To reach Guirdil bothy, I’d navigated golden glens, hefty bogs and river crossings on foot.

Living in a remote island community comes with its challenges, of course. The nearest doctor is across a body of water. The nearest pub is on the Isle of Skye, and while the general store is well stocked (and does a cracking flat white), when the ferries are delayed, so is fresh produce.

There are, equally, perks. You can see the milky way while walking your dog. Children gaze at shooting stars while their parents carry them home from lively ceilidhs at the village hall. And sometimes you might spy the aurora reflecting off the water.

“It is quite easy to see the milky way on a clear night,” says Fliss Fraser, who runs Ivy Cottage guesthouse, and has lived on Rum for 25 years. “I’ve sat outside and watched quite a few meteor showers. The sky is part of our heritage here and it’s something we need to look after,” she says. Kinloch’s light plan – including downwards lights and removal of motion sensors – will help do this.

Rum is the biggest of the Small Isles, with a volcanic, mountainous ridgeline compact enough to fit in a photo frame but staggering in its immensity. The high peaks – Askival, Ainshval, Hallival – take their evocative names not from Gaelic but Norse, and put visitors in mind of Viking raiders and mythological worlds. Yet this is an island shaped by a long, often painful, human history.

The island’s population peaked in 1795 at around 443, before the Highland Clearances hit Rum. In 1826, 300 people were sent to Nova Scotia, replaced by a sheep enterprise that would ultimately fail just over a decade later. So there was a particular sorrow in Rum becoming the “Forbidden Isle” under the Bullough family, who bought it for deer hunting in 1888, and deterred visitors. In 1957, the Isle of Rum was sold and became the nature reserve it remains today, and the community ownership of Kinloch means people can live there without working for the landowner, NatureScot, Scotland’s nature agency (previously only those employed by them and their families were allowed to reside on the island, with a few exceptions). “It’s the ability to plan our own future,” says Fliss. “We’ve helped create a human landscape for new people to come and live in, and a home for our children.”

It is a cloudy night at Guirdil – the bane of stargazers – but the breeze exposes gaps in the clouds. Through them a sea of stars sparkle, light years away, before disappearing again.

Gray had lamented how “we’ve lost connections that our ancestors had with the night sky”, and at dawn, while watching stags rutting, clashing antlers in a fight for dominance, I imagine how challenging but remarkable life here must have been. There is a comforting smallness in the thought that while Rum changed, its dark skies did not, and that more people might now come to enjoy them.

The darkest months, from October to March, are best for stargazing. “It’s when it slows down here,” says Fliss, who has already welcomed her first dark sky tourists. “It’s a time to rest and rejuvenate.” Though there are plans for a new shop and cafe, as well as a small observatory, the utter peace and quiet of Rum will remain central to its winter allure.

I check into Rum Bunkhouse for the next two nights. It is surely one of Scotland’s finest, looking out over a bay of seals, herons and oystercatchers through huge windows in the comfy lounge.

Posters ask guests to turn off lights when not in use, explaining that it is Manx shearwater fledgling season. “They’re rare birds and Rum holds a quarter of the world’s population,” says Ian Sargent, who manages the reserve. “Over a hundred thousand pairs. When the chicks fledge they depart to winter grounds in South America, but when they first leave the nest they’re vulnerable to light pollution. They can get disoriented.”

I go stargazing on the bay and at the leafy otter hide in the days that follow, having fun with a sky map app, discovering Pegasus, Cassiopeia, the Boötes constellation and so on, but failing to spot the Tsuchinshan-Atlas comet, visible to humans for the first time in 80,000 years.

My ferry back leaves in the dark, and it’s as I walk to the harbour that the skies properly clear to reveal a world of satellites, shining planets and shining stars, some blazing, others tiny and dim. As we sail to the lights of Mallaig, I can’t help but wish I was back at Guirdil bay, gazing up in wonder.

Travel to Rum was provided by Visit Scotland. A bed at the community-owned Rum Bunkhouse costs from £32.40 per night, with private rooms from £84. Guirdil bothy is maintained by the Mountain Bothies Association. Read its bothy code before visiting.