CMO/OAA Cahier #09
Halleyfs Comet Observed by Ch HUYGENS
This is a translation of the Japanese article published in the Heavens (Journal of the OAA) in October 1985.
ounting from 1986, 76~4=304 years before, the Halley comet in 1682 observed by Edmond HALLEY was observed equally by the famous astronomers such as HEVELIUS, CASSINI, FOOKE, NEWTON, BOYLE, FLAMSTEED and so on: Here we should add Christiaan HUYGENS (1629~1695). He left an excellent sketch of the Halley Comet:
The drawing in Fig 1 is found@in the K Manuscript of the@Œuvres Complètes de Christiaan Huygens Tome 15 p131@and seems to have been produced on 5 or 6 September 1682 at around 8 PM (5 ve1 6 Sept. 1682. hora 8 vesp).
He was poor in health and left off his long study
On the other hand he wrote a letter to his brother Constantyn HUYGENS on 13 September 1682 (Tome 8, p390) and reported that he observed the Comet by the 12 pieds telescope and added the sketch. Figure 2 is the one and must have been a copy of the comet in the K Manuscript. In the letter Christiaan described that the head is small but bright like a point as was the case in the comets in 1664 and 1665, and pointed out that to the direction of the Sun a stream of water vapour was thickly protruded, though it was not like the tail. He also alluded to the inconvenience of 21 pieds telescope for the observation of the comet.
In the K Manuscript, he reported furthermore that he had begun to observe the comet from 8 to 10 days before, and pointed also that it had a brightening nucleus at the head, and the tail was 8 to 10 degrees in length pointing to the opposite direction of the Sun. The altitude of the comet above the horizon was about 15 degrees, and the direction was between the north and the west. It seems he observed several days, and described that the motion was rather swift from the pole to the westwards direction.
The sketch of the comet appears quite excellent to the present writer.