The finest expression of YEMA’s savoir-faire
“Millésime” stands for the very best YEMA can produce: a premium, handcrafted, and highly limited timepiece that embodies the legacy of French horology and our ongoing pursuit of excellence.
The most intricate and complicated piece produced by the manufacture this year pays tribute to a founding place in the cradle of French watchmaking: the Besançon Observatory. In 1878, the city built an observatory for a single reason, to allow its watchmakers to set their watches by the stars.
The Spacegraf revives this founding gesture. On its dial, an entire disc turns to the rhythm of the real sky, this is the sidereal time complication, displaying at every moment the stars actually visible above you. At its center, a second rhythm, far faster: the flying tourbillon of the CMM.32 caliber, manufactured in Morteau, visible both from the front and through a sapphire caseback.
This is the story the Spacegraf tells on the wrist: that of a region which has always measured time by looking to the sky.
Limited to 150 numbered timepieces.
3D Grade X1 Super-Luminova
The hour markers and hands are shaped from solid 3D blocks of Grade X1 Super-LumiNova BGW9, so they glow through their full depth. At night, the celestial disc lights up too: a luminous sky on your wrist.
Forged in Titanium, Open to the Stars
Like the Besançon Observatory, the Spacegraf opens onto the sky. Its 42mm Grade 5 titanium case is vertically brushed and framed by a circular-brushed bezel, and it holds the complication in just 12.15mm. On top, a double- domed sapphire crystal serves as the dome, with a clear view of the celestial disc and the flying tourbillon.
Celestial Dial
The dial is deep black, with a fine sandblasted grain under a black PVD coating, ringed by circular-brushed minute and seconds tracks. At 12 o’clock, the “celestial vault” disc turns once every sidereal day (23h 56min 4s) under a thin sapphire cover that shades from smoky to clear. At 6 o’clock, the flying tourbillon opens the dial onto the movement. The indexes are merged into 3D rings and, along with the numerals, tracks, hands and celestial disc, are treated with Super-LumiNova BGW9 Grade X1. At night, the whole sky glows on the wrist.
Sidereal Time
Meridian Circle of the Besançon Observatory
In 1878, at the request of Besançon’s watchmakers, a presidential decree established an astronomical, meteorological and chronometric observatory in the city. Its purpose was to certify the precision of their watches by observing the stars. It had dedicated pavilions, aligned with absolute precision, including a meridian circle with an opening roof. The observatory is still active today, affiliated with the CNRS (France’s national research centre) and working in time-frequency metrology.
The meridian circle looks at only one point in the sky: the line where, every night, the stars cross the observatory’s north- south axis. From each crossing, astronomers drew two certainties at once: the exact time and the star’s position. Besançon’s watchmakers came for this direct reading of the sky, rather than calculation, to regulate their watches.
The Spacegraf’s “celestial vault” disc brings this principle to the wrist. The meridian circle caught the sky as it passed in front of its fixed telescope. The disc instead turns continuously, set to the same 23h 56min 4s the Earth takes to turn once on its axis relative to the stars. At every moment, it shows the part of the sky actually visible above you: the same data the Observatory read from its stars, now in perpetual motion on a dial.
The Flying Tourbillon, a Symbol of High-Horology
A true masterpiece of watchmaking, the flying tourbillon ranks among the most complex complications to produce, offering a fascinating visual spectacle thanks to its mechanism, supported solely by its base, which gives it the illusion of floating in space.
Designed to counteract the effects of gravity and improve timekeeping precision, this device demands exceptional mastery: the absence of an upper bridge requires perfect balancing of the components, lightweight materials to reduce friction, and hundreds of hours of meticulous work.
