Looking at the sky and observing the day and month is the basis for people to make time and work when the machinery is not invented. The medieval European church bell tower is marked with constellations and sun symbols, which illustrates the development of astronomy and watches over the centuries Nowadays, with the vigorous development of modern timepiece machinery, astronomical timepieces have never been absent, especially with the assistance of today’s precision instruments. The difficulty of making astronomical timepieces is not out of reach. The watch on the list has repeatedly appeared.

For Jaeger-LeCoultre, an exceptionally strong Jaeger-LeCoultre, it is not difficult to launch an astronomical watch, but it is too “easy” to just put a starry sky map on the faceplate. Therefore, the Master Grande Tradition Grande Complication watch was released. He is also a member of the Hybrid Mechanica complex series, letting go to integrate three major complex functions-three questions, perpetual calendar and tourbillon, to re-draw the starry night sky of the northern hemisphere.

The incredibly light tourbillon floats above the faceplate and makes a full revolution around the outer edge of the faceplate. It also records the trajectory of stars in the night sky, indicating the stellar time four minutes slower than the usual solar time.

Presenting the night sky above the northern hemisphere, the deep color and exquisite mechanical carving are fascinating. Not only that, Jaeger-LeCoultre specially added the flying tourbillon device, and at the same time it is the first revolving tourbillon in the brand. When the tourbillon follows the faceplate ‘One day’ makes one full revolution, and the face of the northern hemisphere starry sky map means that the stars on the plate have also gone one day. It is worth noting that the day defined here is not the usual 24 hours used, but a stellar day that is 4 minutes slower, and the stellar day is not based on the sun, but is referenced by other stars. Is the 24-hour time scale indicating the general solar day. In addition, Jaeger-LeCoultre carefully depicts the names and locations of the horoscopes on the faceplate. With the outer month and corresponding constellation symbols, it can grasp the constellation position at any time of the year.

One day is generally defined as one rotation of the earth’s rotation, but astronomy has different definitions due to reference points. For example, the sun in the picture is labeled as the common solar time. Because the earth’s rotation and revolution, it is slightly longer than the stellar time.

The suspended tourbillon has a vibration frequency of 28,800 revolutions, which is rarer than ordinary tourbillons. It is more accurate, but on the other hand it also means more energy consumption. Therefore, the Jaeger-LeCoultre tourbillon frame is made of titanium. The escapement fork and escapement wheel are made of lightweight and non-lubricated silicon material, both of which can greatly reduce weight and effectively transmit power, which improves the efficiency of the movement by 15%.

Continuing the crystal sound spring developed in 2007, and the sound mechanism of the scale hammer extended from the trebuchet in 2009, the crisp bell chime celebrates the beauty of the stars

The minute repeater is another highlight of the model. The crystal gong technology developed by the master repeater is used. The square cut surface can expand the contact area with the hammer and improve the percussion quality. And adopt the balance hammer design developed by the big self-sounding watch. At the end of the hammer, connect a steel cable with the hammer and a spiral hairspring, which can increase the power transmission to 80% and make the hammer more powerful. When the power is activated, the volume and sound quality are more prominent, and the moving music under the beautiful starry sky is composed.

Master Grande Tradition Grande Complication

18K white gold material / 945 manual winding movement / hour and minute display / minute repeater function / perpetual calendar function / flying tourbillon device / northern hemisphere star map display / sapphire crystal, transparent bottom cover / waterproof 50 meters / table diameter 44mm / limited 75 pieces / Reference price: 2,363,000 RMB