A guide to what's up in the sky for Southern Australia

Comet Pons-Brooks (10th Apr 2024)

Looking west on the evening of April 27., 30 minutes after sunset. Locate the orange star Aldebaran, then scan to the left until you come to a fuzzy spot in the sky. Train your binoculars on it, the comet will be 239 million kilometres away. Graphic generated with Stellarium planetarium software.

The appearance of a “hairy-star”. We will be looking forward to seeing a naked-eye visitor to the evening sky in late April and into early May.

Comet 12P/Pons–Brooks is a periodic comet with an orbital period of 71 years. Comets with an orbital period
of 20–200 years are referred to as Halley-type comets. It is one of the brightest known periodic comets, reaching naked eye visibility on most returns. Comet Pons-Brooks was discovered at Marseilles Observatory in July 1812 by Jean-Louis Pons, and on its next appearance in 1883 by William
Robert Brooks. There are ancient records of comets that are suspected of having been apparitions of 12P/Pons–Brooks, as far back as 245 CE.

The next close approach to the Sun occurs on 21 April 2024, with closest approach to Earth of 232 million kms on
2 June 2024. The comet nucleus is estimated to be around 30 km in diameter.

The best time to see the comet is from late April until about May 10. There’s no Moon in the sky to interfere. As
the chart shows below, look low in the west about an hour after sunset. Once you spot the fuzzy object, grab your binoculars and get a closer look. It’s very difficult to predict what the comet will do after its close approach to the Sun on April 21.

Image of Comet Pons-Brooks taken by Borut Prasnikar on
March 13, 2024 @ Blegos, Slovenia. (Nikon Z6 ISO 4500, 105mm, f2.8, 20 x 30sec exposure. Andromeda galaxy is at topright.

As the comet is heated by the Sun, it may outburst and brighten, or perhaps most of its volatile components may
have already been used up, and we’ll see no change. Somebody once said, “Comets are like cats. They do what they bloody well want to!”

Your best chance of seeing this visitor from the outer solar system is to make sure you travel to a dark sky, have a very clear western horizon, and have a pair of binoculars ready.

Happy hunting!!