C/1941 B2 (de Kock–Paraskevopoulos)

Lore & Background

The comet was first observed by Reginald Purdon de Kock in Paarl, South Africa on 15 January 1941 while he was observing the variable star R Lupi. He estimated its magnitude at 5.8 and its tail at half a degree. Frank Skjellerup independently discovered it in Melbourne on 20 January, and a person named Barnes also notified Melbourne Observatory about the comet on 21 January. John S. Paraskevopoulos of the Harvard College Observatory in Bloemfontein, unaware of the other discoveries, found the comet on 23 January and sent a radiogram to Harvard College, leading to its being known in the United States as comet Paraskevopoulos.

The comet brightened rapidly to magnitude 2 to 3 in the following days, with its tail reported at about 5 degrees. It reached perihelion on 27 January and made its closest approach to Earth two days later at 0.2655 AU. On 27 January it also reached its southernmost declination of -57°. Harley Weston Wood reported a magnitude of 3.26 and a tail length of 5° by naked eye on that day. Ronald Alexander McIntosh reported magnitude 2.2 and a tail length of 6 degrees on 31 January.

In February the comet began to fade as it moved away from both Earth and the Sun. The tail appeared bent in the first days of the month. By mid-February the comet had faded to about magnitude 5 and was no longer visible with the naked eye. In March the solar elongation decreased, and the comet passed 0.6 degrees from the Sun on 28 April. It was recovered on 4 July by George van Biesbroeck and last detected on 27 September 1941.

Reader's Guide

The comet C/1941 B2 (de Kock–Paraskevopoulos) is significant as a bright non-periodic comet that reached naked-eye visibility in the southern hemisphere during early 1941. Its independent discovery by three observers across South Africa and Australia highlights the coordinated observational networks of the era, with John S. Paraskevopoulos's radiogram to Harvard College ensuring its recognition in the United States. The comet's rapid brightening to magnitude 2–3 and its tail extending up to 6 degrees made it a striking object for southern observers. Its perihelion on 27 January and close approach to Earth at 0.2655 AU on 29 January provided a brief but intense period of visibility. The comet's fading in February and its passage within 0.6 degrees of the Sun on 28 April marked its transition to a difficult object, though it was recovered in July and tracked until September 1941. The comet's legacy lies in its well-documented observational history, including magnitude estimates and tail measurements by multiple astronomers, and in its role as a notable example of a non-periodic comet that brightened rapidly near perihelion.

Did You Know?

• The comet was independently discovered by three people: de Kock, Skjellerup, and Paraskevopoulos.
• It reached its southernmost declination of -57° on 27 January 1941.
• The comet passed only 0.6 degrees from the Sun on 28 April 1941.
• It was last detected on 27 September 1941.