Ref. 5106 Celestial – Unique Piece
The case, in 18kt rose gold (with a bezel of 22kt rose gold), measures 44mm x 11mm. It is water resistant to 30 meters.
Movement is the automatic Patek caliber in-house 240LUCLC with 45 jewels and a power reserve of 48 hours. The movement measures 38mm x 7mm. Functions are: hours and minutes of local time (mean solar time), sky chart, time of meridian, passage of Sirius, time of meridian passage of moon, lunar orbit, moon phase and date on perimeter of dial.
The dial features three metalized sapphire crystal discs, with a apphire crystal glass with 31 metalized Arabic numerals as well as ellipse framing the portion of the sky visible from Geneva.
Notes
A lunar day is defined as the time between two consecutive passages of the moon across a specific meridian and on average lasts 24 hours, 50 minutes, and 28.328 seconds. A lunation – the time between two consecutive full moons – averages 29 days, 12 hours, 44 minutes, and 2.82 seconds. A sidereal day is the time it takes for a fixed star (such as Sirius) to make one complete passage across a specific meridian and averages out to 23 hours, 56 minutes, and 4.09892 seconds. These deviations from mean solar time call for appropriate step-up or step-down transmission ratios in the gear trains that transfer the force from the mainspring barrel of the movement to the individual astronomical displays. So far, some of these ratios known in horology have delivered a more accurate moon phase display and a less accurate solar day, others have reproduced the solar day more accurately than the orbit of the moon.
But after having calculated more than 25 trillion (25,000,000,000,000) ratio combinations, Patek Philippe discovered the one single ratio that produces the highest degree of precision in all displays. The result surpasses all expectations:
* The lunar day is accurate to 0.05 seconds per day, 18.385 seconds per year, or 30 minutes and 38.5 seconds per century.
* The day is accurate to 0.088 seconds per sidereal day, 32,139 seconds per year, or 53 minutes and 33.9 seconds per century.
* The moon phase is accurate to 6.51 seconds per lunation
