Watches: Antoine Martin Tourbillon Astronomique

By Thierry Ané on March 20, 2014

Today I would like to introduce an impressive timepiece that will be officially unveiled at Baselworld by Antoine Martin. I will of course come back on this model with a more detailed presentation and live pictures.

Antoine Martin is a relatively new brand that made its first appearance at Baselworld 2011 with no less than a Perpetual Calendar developed in-house. The piece was technically impressive and aesthetically, I was immediately won over by the generous 46 mm case with a very distinct and masculine style. I particularly like the stainless steel version with an open dial of this Perpetual Calendar.

For 2012, the brand came back with the same beautiful case and overall look but added a tourbillon to the perpetual calendar complication. The regulator display of the Perpetual Calendar Tourbillon was particularly interesting as it gave an uncluttered look to a model with quite a lot of indications on the dial.

Last year, the brand presented another amazing piece in a reduced 42 mm case, the so-called Slow RunnerWatches: Antoine Martin Slow Runner which I have discussed on Watch Agora before. It was another stunning piece beating at one hertz with a gigantic 24 mm balance whose low oscillations can be admired from the sapphire case back. The piece is absolutely hypnotic to look at and I strongly encourage you to have a look at my articleWatches: Antoine Martin Slow Runner or at the technical forms in our database if you don’t know this model (steel with silver dial, steel with black dial or pink gold with silver dial).

This year, the brand will officially present its most complex timepiece so far, the Tourbillon Astronomique. At this point, those of you not familiar with the brand may rightfully wonder how such a young brand can come up with such astonishing timepieces in such a short time. The answer is simply the name of the watchmaker behind the brand: Martin Braun.

This very talented watchmaker is definitely not new to the game. He created some amazing astronomic models for the brand that bears its name and belongs to the Franck Muller group. Some disagreements later, Martin Braun the brand has not produced anything relevant in recent history, but Martin Braun the man is the driving force behind Antoine Martin. This year, Antoine Martin explores the world of astronomic displays for the first time, obviously at the instigation of Martin Braun.

The stunning Tourbillon Astronomique displays the time of the day by two central hands and features the same beautiful tourbillon as the Perpetual Calendar Tourbillon. It also indicates the date by hand on a little sub-dial at 1 o’clock that slightly impinges on the edge of the glass. The astronomic complications take a lot of space in the movement and this was the only way of including a date large enough to be easily legible.

Between 11 and 12 o’clock, you will find an equation of time. For those who don’t know this complication, the equation of time describes the discrepancy between two kinds of solar time. The apparent solar time, which directly tracks the motion of the sun in the sky, and the mean solar time, which tracks a fictitious "mean" sun with noons exactly 24 hours apart. In this watch, this complication is synchronised with sunrise and sunset times and they do not need to be set independently.

Martin Braun’s astronomic displays par excellence, the sunrise and sunset times, face one another at 2 and 4 o’clock in grey sub-dials. The control cams that enable this display will be individually produced for each customer given the latitude and longitude of his choice.

Just in between on the dial, another sub-dial in a lighter shade of grey displays the sign of the zodiac and the season. This is quite an unusual complication and those with a particular affinity to astrology will undoubtedly appreciate it. The reason for its presence, however, is more pragmatic: it is here to simplify setting the system! Indeed, each watch is supplied with a table from which the customer can read off the sunrise and sunset times for the location of his choice. All he needs to know to make a correct reading is the sign of the zodiac and the season, hence the presence of these indications.

On the other side of the dial, at 9 o’clock, a large aperture reveals an extremely realistic moon with its most important craters and seas clearly visible. A semi-transparent shadow gradually moves across the moon until new moon (i.e. when no crescent is visible). At this point, the disc changes direction (it is thus retrograde) and moves the other way until it reaches full moon. A little indicator at 12 o’clock tells you whether the shadow is moving towards full moon (i.e. is waxing or “+”) or towards new moon (i.e. waning or “-“).

The show on the back of the watch is equally impressive. The remaining energy of this 6-day power reserve timepiece is indicated in the brand’s characteristic comma-shaped aperture at 6 o’clock. A beautiful plaque bears the name of the model, “Tourbillon Astronomique” as well as the place selected by the customer as a reference for the astronomic indications with the latitude and longitude.

The most spectacular part of the case back is of course the generous bullet-shaped aperture in its middle with a detailed world map. It is used to indicate the declination angle both visually with the red line and numerically on the left-hand side of the world map. The declination indicates the latitude at which the sun stands 90° above the horizon at noon (i.e. the latitude at which a stick standing upright in the ground would cast no shadow). Lastly, the watch indicates the polar shadow, i.e. the area in which the sun does not rise. Once again, all these indications are synchronised with the sunrise and sunset and do no need to be separately set.

The Tourbillon Astronomique is presented in what can now be regarded as the trademark case for the brand, crafted in pink gold (although a white gold version may come soon). It is mounted on a beautiful brown alligator strap with a deployant buckle in pink gold and features a silver dial that seems to have a circular guilloché silver chapter ring and a brushed or opaline silver-tone centre (more on this after Basel of course). Limited to 12 pieces, it will retail for 500,000 CHF. This is a sensational model that I real look forward to see in person during the fair.

For a technical description of the timepiece and additional pictures: