For SIHH 2017, Vacheron Constantin have released one of their most complicated pieces ever, and most likely their most complicated wristwatch. Last year, we saw the Vacheron Constantin Reference 57260 Pocket Watch, aka the most complicated watch ever created, with 57 complications. The new one-of-a-kind Vacheron Constantin Les Cabinotiers Celestia Astronomical Grand Complication 3600 watch Ref. 9720C/000G-B281 looks to the stars with 23 complications, the vast majority of which are astronomical complications.

Unlike the Reference 57260 pocket watch which measured 98mm wide, 131.7mm tall, and 50.55mm thick, the Vacheron Constantin Les Cabinotiers Celestia Astronomical Grand Complication 3600 watch is 45mm wide and just 13.6mm thick. The caliber 3600 movement, composed of 514 components is 36mm wide and 8.7mm thick by itself. According to Vacheron Constantin, it took five years to develop and build the new Caliber 3600 movement which, in addition to successfully housing 23 complications, has six barrels providing 21 days (that’s three weeks) of power reserve. The manual-winding movement includes 64 jewels, as well.

The watch itself is, as I previously mentioned, 45mm wide with an 18k white gold case. The case back reveals the Celestial Chart, with the words “Pièce unique” and “Les Cabinotiers” engraved on the sides. As for the front of the watch, the opaline slate gray dial is marked with 18k gold markers and hands. It’s easy to forget about things like the strap when you’ve got so much going on with the watch, but it comes on a Black Mississippiensis alligator leather strap with 18k white gold clasp.

Defined here, “complication” is going to refer to anything beyond the hours, minutes, and seconds which make up simple timekeeping. Unless I am missing something (and given the SIHH schedule, I may very well be…), I do count 23 but with “3 weeks of power reserve (6 barrels” and “power reserve indicator” as two separate item lines. We’ll make sure to look into that and update you guys, but below is the full list of the complications. We’ll start with the complications you can see on the dial from the front:

Calendar & Moon Phase

• Aperture-type day display is between 12 o’clock and 1 o’clock
• Pointer-type date display sits at 3 o’clock with a neat squiggle hand to break up the potential repetitive look with so many hands on the dial
• Aperture-type month display
• Aperture-type leap-year display sits just ahead of 2 o’clock
• Perpetual calendar
• Day/night indication is situated at 9 o’clock with a concentric circle that is visible through the moon phase disc
• Precision moon phase disc
• Age of the moon- the numerals and indices running up the day/night indicator track the lunar cycle as measured between 1 & 29.5 days

Solar Time

• Equation of time is tracked by the gold minutes hand. Since the 24-hour day is determined by an average number, this hand monitors the “true” solar time which can range from a few seconds to over 16 minutes in how much it varies from the standard minutes hand.
• Running equation of time- Vacheron Constantin has patented a “tropical gear train” simulating the 365.2421898 days of a tropical year where the previously mentioned solar hand is set.
• Sunrise time- running on UTC+1, the gold subdial at 7 o’clock runs from 4:30am to 8:30am indicating sunrise.
• Sunset time – functions same as above but goes from 4:30am to 8:30am, indicating the time of sunset.
• Length of day – the aperture at 6 o’clock has a gauge measuring the number of daylight hours in gold
• Length of night – functions like the above, but with black to indicate nighttime
• Seasons, solstices, equinoxes and zodiacal signs – the subdial at 4 o’clock here indicates Solstices (when the sun is at its furthest or closest point from the equator) and Equinoxes (when night and day are equal length) as well as tracking Zodialogical signs through icons.

Mareoscope

• Tide level indicator- between 10 o’clock and 12 o’clock is a subdial indicating tide levels, whether the tide is ebbing or flowing, and high or low tide.
• Sun-Earth-Moon conjunction, opposition and quadrature is essentially a 3D rendering of the sun, earth, and moon tracking their positioning which affects the tides.

And once you turn it around to view the case back:

Celestial Chart

• The Celestial Chart, to start, is the same thing as a star chart which tracks the movement of the stars, constellations, and other astronomical objects. Here, it’s created from two superimposed sapphire discs. The transparent disc in the foreground depicts the Milky Way and constellations as seen from the Northern Hemisphere, as well as the months of the year. This transparent disc also has two ellipses- one in red and one in white corresponding with the ecliptic and celestial equators, respectively. The second disc has display scales on the rims indicating Celestial time hours and minutes as well as well as a black ellipse revealing a view of the celestial chart.
• Celestial time hours or “sidereal hours” measure earth’s rotation just like standard or “mean” time, but varies approximately 4 minutes per day.
• Celestial time minutes

And the rest:

• Tourbillon
• 3 weeks of power reserve (6 barrels)
• Power reserve indication

The Vacheron Constantin Les Cabinotiers Celestia Astronomical Grand Complication 3600 Watch looks absolutely stunning and marks another year of technical watchmaking accomplishment. Price is somewhere just around $1,000,000. vacheron-constantin.com