Yema Adds A Star Map To The Tourbillon For The 2026 Edition Of The Millésime

Every year Yema picks one watch to call its Millésime, a French wine term for a vintage year. It’s the most complicated and most limited thing the brand makes that year, built by hand in Morteau around its own movements. Last year that was the Superman Tourbillon CMM.31, a titanium dive watch with a tourbillon, limited to 100 pieces at €12,000. Nobody asked for it, and a few people bought it anyway. This year’s Spacegraf Heure Sidérale Tourbillon Volant drops the dive bezel and adds a sidereal time display to a flying tourbillon. And it's even more expensive.

The case is made out of grade 5 titanium, 42mm wide and 12.15mm thick, with vertically brushed flanks and lugs and a circular-brushed bezel with polished edges. That’s a smaller footprint than last year’s 43mm Superman and a reasonable thickness. On top sits a 1.60mm thick double-domed sapphire crystal, the crown is a titanium push-pull, lug width is 21mm and water resistance is 100 meters.

The dial is black, sandblasted and PVD coated, with brushed minute and seconds tracks around the edge. The disc at 12 o’clock is a very interesting complication, most seen on much, much, much more expensive watches. It completes one rotation every 23 hours, 56 minutes and 4 seconds, the time Earth takes to turn once relative to the stars, so it gradually drifts against the hour hand and shows you the sky overhead. It sits under a sapphire cover tinted smoky at one end and clear at the other. The tourbillon takes up the lower half at 6 o’clock. Indices are raised 3D rings of Super-LumiNova BGW9 Grade X1, and the numerals, hands, tracks and the star disc are lumed too, so the whole map glows in the dark. My one question is which latitude the map is drawn for, because a single disc can’t show the correct sky everywhere you might wear it.

Inside is the CMM.32, made by Yema in Morteau. Accuracy is rated at -3/+7 seconds a day and the power reserve is 105 hours from a single off-centre barrel supplied by Générale Ressorts. The escapement parts are made using LIGA, the hairspring is non-metallic, and Yema rates the movement to 2,000 Gauss and 5,000 Gs thanks to Kif shock absorbers. Those are serious numbers for a tourbillon, which is usually the most fragile thing in a watch. Through the caseback you get blue bridges engraved with constellations and a flame-blued ratchet wheel with a map of the Earth. It comes on a black leather strap tapering from 21mm to 16mm, closing with a titanium pin buckle.

The Spacegraf Heure Sidérale Tourbillon Volant is limited to 150 numbered examples, with a price set at €14,500. See more on the Yema website.