April: The Lion’s share of intriguing galaxies

Centaurus A, aka the Hamburger Galaxy (NGC 5128), is the fifth brightest galaxy in the sky, making it an ideal target for amateur astronomers. It’s an active galaxy about 12 million light-years from Earth and is famous for the dust lane across its middle and a giant jet blasting away from the supermassive black hole at its centre. Photo: MPAS member Guido Tack

Leo plays host to many interesting galaxies that can be seen with relatively modest amateur equipment. These include the Leo Triplet (the M66 Group), a group of galaxies that consists of the bright spiral galaxies M65, M66 and NGC 3268; and the Leo I Group (M96 Group), a group of between eight and 24 galaxies that includes three bright Messier galaxies: the spirals M95 and M96 and the elliptical galaxy M105. They are found clustered around a region at roughly the halfway point between the stars Chertan (Theta Leonis) and Regulus (Alpha Leonis). M65 and M66 appear as grey smudges of light through a small telescope.

The very finest of all globular clusters is the startlingly bright Omega Centauri globular cluster (NGC 5139). At 13 billion years old and containing a million stars, NGC 5139 is thought to be the nucleus of a dwarf galaxy that collided with the Milky Way. It can be found by making an equilateral triangle using The Pointers, the Southern Cross (Crux) and Epsilon Centauri.

But by far the most impressive sight with the unaided eye is the great arc of the Milky Way galaxy. It stretches all the way from the magnificent region in the east around the constellations Scorpius and Sagittarius, through Crux, Carina and Vela, and down to Puppis and Canis Major.

The Lyrid Meteor Shower is usually active between April 16 and 25 every year. It tends to peak around April 22 or 23, and by ‘peak’ I mean the most you could expect to see is up to 18 meteors an hour. Named after the constellation Lyra, it is one of the oldest recorded meteor showers. According to some historical Chinese texts, the shower was seen more than 2500 years ago. The fireballs in the meteor shower are created by debris from comet Thatcher, which takes about 415 years to orbit the Sun. The comet is expected to be visible from Earth again in 2276.

By Nerida Langcake
This article appeared in the April 2022 issue of the Mornington Peninsula Magazine.