King Tincomarus of the Atrebates was a client king of Rome. He ruled southern and central Britannia starting in 25-20 BC. He was educated in Rome and brought Roman coin technology to Britannia. The star symbol on the coin is in reference to the divine comet of Augustus which was seen at the time of the death of Julius Caesar. This may have been the brightest daylight comet in human history.
The Romans would use astronomical symbols to justify annexation of new provinces. The divine comet of Caesar was minted on the coins of Augustus in 19 BC. Bear in mind the comet of Caesar occurred in 44 BC which was 24 years before this coin was minted. We seen this theme later on the Antioch ram coin series with the annexation of Judea in 6 AD. Photo Munzhanlung Ritter