Late in September 1888, Van Gogh had tried and failed to paint Christ in the garden of Gethsemane under a starry sky, a picture he judged such a miserable failure that he destroyed it. Rather than abandon the idea of a night sky altogether, he shouldered his equipment in the middle of the night and went looking for a real subject he could paint directly under the actual stars, a few blocks from where he lived, on a seawall above the Rhône^[1].

Van Gogh set his easel under one of the gas lamps that lined the riverbank for light to paint by, though he knew its golden glow could be deceptive: he admitted that in the dark he might mistake a blue for a green or a blue lilac for a pink lilac, since it was hard to judge a hue's true quality by lamplight. He judged the immediacy of working straight from the scene more important than strict accuracy, and the only way to escape what he called the poor, sallow, whitish light of a conventional night picture^[1]. Looking south down the river, he found the dark profile of Arles reduced to a jagged silhouette against the sky, its handful of lit windows and the black shapes of moored boats the only other marks on the scene^[1].

He began the sky by laying out the stars of Ursa Major, the Big Dipper most prominent among them, at the centre of the canvas, but the longer he looked the more his brush wandered from that plan. He described seeing dots and smudges, perfect circles and misshapen fragments, some stars pale pink or green and sparkling like jewels, and compared his own arranging of them to a jeweller setting stones to enhance their value. To some he gave coronas of radiating strokes, like flower petals or fireworks, an effect he linked to the citron nimbus around the head of Christ in a Delacroix painting he admired^[1].