The Longines Comet, a short-lived mystery dial from the seventies, is an unusual watch from Longines, featuring a broad arrow for hours and an orbiting dot for minutes. Both are on revolving discs, making them appear to move without being connected to the dial, hence the term 'mystery dial'.
The indication 'T Swiss Made T' on the bottom of the dial means that the watch contains a certain quantity of tritium that emits less than 227 MBq (7,5 mCi). This particular watch still has some lume appearing on the tips of the markers when the watch is placed close to the light of a lamp; natural light does not seem to have any effect. The dot and the arrow have a tendency to discolour to a yellow colour over time.
The indication 'T Swiss Made T' on the bottom of the dial means that the watch contains a certain quantity of tritium that emits less than 227 MBq (7,5 mCi). This particular watch still has some lume appearing on the tips of the markers when the watch is placed close to the light of a lamp; natural light does not seem to have any effect. The dot and the arrow have a tendency to discolour to a yellow colour over time.
The watch is considered to be uncommon, as the design was deemed too avant-garde for tastes at the time, so comparatively few were sold. Red is the most rare colour, followed by yellow, the most common colour being blue. It was also produced in black and white, and in brown, maroon and green variations.









