Comet C/2021 A1 (Leonard) in Southern African skies

28 December 2021, Tim Cooper

Discovered on 3 January 2021 by Greg Leonard at Mount Lemmon Observatory, the comet was expected to be the brightest comet of 2021, and was predicted to peak at about magnitude 4 around closest approach to Earth on December 18. After that it was expected to fade as it became visible in southern skies during the early evening from December 18 onwards. But when it re-emerged from the solar glare it was clearly undergoing an outburst. Two further outbursts occurred on December 20 and 23, both times resulting in the comet being visible to the naked eye from dark sky sites, and sporting a beautiful tail (image courtesy Kos Coronaios). With perihelion occurring on 2022 January 3, at which time the comet comes under its maximum warming by the sun, further outbursts may still occur.

The graphic shows where to find the comet during the first week of January. It should be easy to find just below the star Aldhanab (gamma Gruis, magnitude 3.0) in the constellation of Grus, the Crane. During January evenings the comet sets earlier each evening, and will be lost in the solar glare again by mid-month.