Launched in 2002, the ‘Celestial’ is arguably one of the most game-changing horological complications ever engineered. This astronomical wristwatch adopts the principle of the celestial canopy from the most complicated Patek Philippe wristwatch, ref 5002, the Sky Moon Tourbillon. The reference was first realised in platinum, before the yellow gold variant was later introduced for two years only, from 2007 to 2009.

A celestial dream on the dial, the nocturnal sky of the Northern Hemisphere rotates to depict the apparent angular motion of the stars and moon, along with the progression of the phases of the moon. Three sapphire crystal discs are seamlessly layered on top of one another to simulate the dynamic orbit of the moon and the passage of the stars, hence rendering it a remarkable sense of depth. The hours and minutes are indicated by two hollowed hands in white. A delicate elliptical contour on the inside of the glass frames the portion of the sky visible from all cities sharing the latitude of Geneva.

To achieve the highest possible exactitude for the astronomical displays, the engineers of Patek Philippe researched 25 trillion (25,000,000,000,000) ratio combinations, showing the enormous horological challenge the model represents. Through its sapphire caseback, the wearer is invited to admire the highly sophisticated automatic cal. 240 LU CL which consists of 301 meticulously hand-finished individual components.

Phenomenal both inside and out, the present astronomical masterpiece is armed in a full yellow gold case with detailed Calatrava crosses etched onto the casebands for added grandeur. The Celestial ref. 5102J at hand is exceptionally rare and is the 23rd yellow gold example known to the market. The epitome of elegance and technical sophistication, this example will no doubt please connoisseurs of the most important timepieces in haute horology.