Yema Releases Spacegraf Heure Sidérale Tourbillon Volant for EUR 14,500
French watchmaker Yema has expanded its Millésime series with the Spacegraf Heure Sidérale Tourbillon Volant, a 150-piece limited edition priced at EUR 14,500, Monochrome Watches reported. The watch pairs a flying tourbillon with a rotating celestial display that tracks sidereal time.
Following the Superman Tourbillon Millésime CMM.31 released the previous year, the 2026 model shifts focus from professional dive watches to astronomical complication. The timepiece houses a hand-wound Calibre Manufacture Morteau CMM.32 movement developed alongside watchmaker Olivier Mory. Power reserve reaches 105 hours via a large mainspring barrel. The movement withstands shocks, vibrations, and accelerations up to 5,000 Gs in all directions, utilizing Kif shock absorbers and a free-sprung balance wheel architecture.
Grade 5 Titanium Case and Astronomical Dial Layout
Housed in a 42mm Grade 5 titanium case measuring 12.15mm thick, the Spacegraf features alternating brushed finishes and polished accents alongside a double-domed sapphire crystal. Water resistance is rated to 100 meters, enabled by a push-pull titanium crown bearing the Yema logo.
The black PVD-coated dial features a fine sandblasted texture. At 12 o’clock, a rotating celestial disc completes one revolution every sidereal day—lasting 23 hours, 56 minutes, and four seconds—measuring Earth’s rotation relative to distant stars rather than the Sun. At 6 o’clock, a flying tourbillon operates alongside a small seconds hand mounted directly on the tourbillon cage. Super-LumiNova elements illuminate the hands, hour markers, and celestial disc aperture in dark blue.
Besançon Observatory Heritage and Technical Specifications
The astronomical theme ties directly to the history of Besançon, France, where an observatory was established by presidential decree in 1878 at the request of local watchmakers. Local artisans used observations of stars crossing a fixed meridian to regulate their timepieces. The CMM.32 caliber incorporates non-magnetic components, including a Swiss-made non-metallic alloy hairspring, a Glucydur balance wheel with gold adjustment masses, and LiGA technology micro-components. These features allow the movement to withstand electromagnetic fields up to 2,000 Gauss. The watch ships on a black leather strap with matching stitching, a titanium pin buckle, and a lining embossed with “Manufacture Française – Fondée en 1948.”