Jacob & Co. ASTRONOMIA SKY


The Jacob & Co. Astronomia Sky is a highly complex astronomical timepiece within the brand's Astronomia collection. It features a three-dimensional sidereal time display, a unique day/night/moon phase complication, a tri-axis flying tourbillon, and a satellite-like four-arm rotating structure, condensing the vast cosmos onto the wrist.

Core Specifications and Functions
Movement: In-house manual-winding JCAM11 movement, 40mm in diameter, 17.15mm thick, 395 parts, 42 jewels, 3Hz frequency (21600vph), 60-hour power reserve; equipped with a tri-axis gravity tourbillon, with each axis rotating once every 60 seconds, 5 minutes, and 20 minutes. The four satellites revolve around the dial every 20 minutes, and a patented differential system ensures the hour and minute dials always maintain the correct 12 o'clock orientation.

Astronomical Display:

Stellar Dial (Blue Grade 5 Titanium, 18K Gold Hand-Engraved Constellations and Stars): Completes one rotation in 1 sidereal year (relative to the orbital period of a star); 12 months are displayed on the side.

Oval Sky Indicator: Completes one rotation in 1 sidereal day (23h56m4s), showing the range of visible stars in the Northern Hemisphere; a Southern Hemisphere version is available upon request.

Day/Night Indicator: Hand-engraved titanium globe, rotates once every 24 hours, positioned beneath a colored sapphire hemisphere to distinguish day and night.

Jacob Cut Moon (1-carat, 288-facet patented cut spherical orange sapphire/diamond), rotates every 60 seconds and revolves around the disc every 20 minutes.

Orbital Seconds: Skeletonized titanium wheel, rotates every 60 seconds and revolves around the disc every 20 minutes.

Case: 47mm in diameter, 25mm thick; available in 18K rose gold, blackened gold, platinum, etc.; sapphire crystal window on the side, unique domed anti-reflective sapphire crystal; water-resistant to 30 meters; rotating crown with retractable lugs; sidereal time adjustment wheels on both sides of the case back.

Strap and Limited Edition: Alligator leather strap, 18K gold folding clasp; most versions are limited to 18 pieces, each individually numbered.

Market and Positioning: This is a top-tier complicated timepiece, typically priced in the hundreds of thousands of US dollars (e.g., the White Diamond version has an official price of $680,000); targeting high-end collectors who appreciate the ultimate in mechanical art and astronomical aesthetics, it caused a sensation at Baselworld with its unprecedented three-dimensional astronomical display and complex linkage structure.


Jacob & Co. Additional Key Points: Sidereal time differs from solar time: a sidereal day (23h56m4s) is slightly shorter than a solar day, and the sidereal year also differs from the Gregorian solar year. This makes the calibration of the Astronomia Sky more professional.

The four-arm satellite system is a signature design of Astronomia, balancing visual impact with mechanical complexity; the tourbillon also resists the effects of gravity, improving timekeeping stability.