Jaeger-LeCoultre has introduced a new interpretation of its Master Hybris Artistica Minute Repeater Cosmotourbillon, presenting the Calibre 945 in an 18K white gold (750/1000) case decorated with grisaille enamel. The watch, limited to five pieces, was announced on 9 September 2026.

Originally created in 2010, Calibre 945 combines a star chart tracking the constellations of the Northern Hemisphere in real time, a minute repeater, and Jaeger-LeCoultre’s flying Cosmotourbillon, which indicates sidereal time. The new edition reworks the watch’s dial through the Manufacture’s Métiers Rares™ atelier, its department for rare artistic crafts, while retaining the calibre’s original technical architecture.

The dial’s celestial imagery is created using grisaille enamel, a decorative technique that originated in 16th-century France and was added to Jaeger-LeCoultre’s repertoire of artistic crafts in 2022. The method builds up light-and-shadow effects through multiple layers of enamel, each fired individually. A deep blue background is laid down first, after which the celestial motif is painted by hand in a white enamel called Blanc de Limoges, producing contrast and a sense of depth. According to the Manufacture, the enamelling work alone requires 24 hours to complete.

The dial itself is constructed in layers. A midnight-blue disc, finished with translucent lacquer over an opaline base, forms the lowest level and carries the months and tourbillon seconds indications. Above it sits a domed gold dial bearing the grisaille enamel celestial scene, onto which the star chart and constellation names are transferred. The tourbillon seconds scale radiates outward from the Cosmotourbillon, an effect the Manufacture likens to beams of light. The entire dial is hand-decorated by Métiers Rares™ artisans.

At the centre of the movement is the Cosmotourbillon, a flying 60-second tourbillon that also functions as a display, completing an anti-clockwise circuit of the dial once every sidereal day — 23 hours, 56 minutes and 4 seconds. This differs from the standard 24-hour solar day used in civil timekeeping, which measures the Earth’s rotation relative to the Sun rather than to the fixed stars. The Cosmotourbillon’s movement corresponds to the Northern Hemisphere sky chart, which shows the real-time positions of constellations as seen from the Vallée de Joux, where Jaeger-LeCoultre has been based since 1833.

The tourbillon is secured on the movement side only, in a flying construction that leaves the regulating organ unobstructed. Its carriage, made of titanium to keep weight low, comprises 73 components in total and is mounted on ceramic ball bearings that do not require lubrication. The balance wheel, a single-metal design measuring 10 millimetres across, beats at a frequency of 4 Hz.

Civil time is tracked separately, via a calendar-driven mechanism that also governs the celestial display, allowing the constellation positions to be set accurately. A gold sun-shaped pointer at the edge of the rotating dial completes one full rotation every 24 hours to indicate this.

The watch incorporates a minute repeater, a complication that translates the time shown by the hands into a sequence of chimes with distinct sounds for hours, quarters and minutes. Jaeger-LeCoultre notes that the mechanical complexity of programming these strikes accurately, while keeping the resulting sound pure and clearly audible, makes the minute repeater one of the more demanding complications to construct.

The Manufacture attributes the acoustic performance of Calibre 945 to several patented innovations it has developed for chiming watches. These include Cathedral crystal gongs, which wrap one and a half times around the calibre and are fixed to the sapphire caseback for greater resonance; Trébuchet hammers, in which the hammer shank is cut in half so it can strike the gong with more force twice over, producing a stronger sound; and a silent governor, designed to regulate the striking mechanism without introducing noise that would interfere with the chime.

The case measures 45 mm by 16.05 mm and is made up of more than 80 parts. Its bezel is convex, complemented by broad bevelled lugs with micro-blasted interior surfaces, while the repeater slide is tapered to follow the curve of the case sides. Surfaces throughout are finished using a combination of micro-blasting, polishing and satin-brushing. There are no recessed setting buttons on the case: all functions are set via the crown, and the minute repeater is activated by a slide on the left side of the case.

The watch is fitted to a blue alligator strap with small-scale alligator lining, chosen to match the dial’s colouring. The 18K white gold folding clasp uses a patented double-wheel adjustment mechanism, allowing the strap length to be adjusted in increments of 0.5 mm.

Technical specifications

• Case: 18K white gold (750/1000), micro-blasted, satin and polished finishes; sapphire caseback
• Dimensions: 45 mm x 16.05 mm
• Calibre: Manual-winding Jaeger-LeCoultre Calibre 945
• Frequency: 28,800 vibrations per hour
• Functions: Hours/minutes, months, 24-hour indication; Cosmotourbillon indicating sidereal time; celestial disc with Northern Hemisphere star chart; minute repeater
• Power reserve: 40 hours
• Dial: Blue, with grisaille enamel decoration
• Water resistance: 5 bar
• Strap: Blue alligator with small-scale alligator lining
• Reference: Q5263482

For collectors already familiar with Jaeger-LeCoultre’s Hybris Artistica line, the Calibre 945 offers a way to revisit a movement first introduced in 2010 without altering its underlying mechanics. What has changed is the dial, now built through the Manufacture’s grisaille enamel work rather than its earlier finishing. That distinction matters to buyers who follow haute horlogerie closely: the technical architecture, including the Cosmotourbillon and minute repeater, remains as it was, while the visual language of the watch has been given fresh treatment by the Métiers Rares™ atelier.

Grisaille enamel is not an especially common sight on a Jaeger-LeCoultre dial outside its more specialised releases, having only entered the Manufacture’s repertoire in 2022. Its appearance here, applied to a celestial theme that already suits the technique’s traditional strengths in light and shadow, gives the watch a distinct identity within the wider Hybris Artistica family, separate from the brand’s more overtly mechanical showcases.

With only five pieces being made, availability will be limited from the outset, and interested collectors are likely to want to move early through their usual Jaeger-LeCoultre contacts. Beyond scarcity, though, the piece is likely to hold particular appeal for those drawn to the pairing of astronomical complications with decorative crafts — a combination that has become something of a signature for the Manufacture’s higher-end output in recent years, and one that continues to distinguish its Master Hybris Artistica pieces from more conventional minute repeaters on the market.

For those simply following the Maison’s output rather than in the market for a piece at this level, the Calibre 945 is a useful marker of where Jaeger-LeCoultre is directing its artistic ateliers at present, and of how established complications can be given new visual treatment without technical redevelopment. It is, in that sense, as much a statement about the Manufacture’s craft capabilities as it is a standalone timepiece.

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Images by Jaeger-LeCoultre.