April: Omega Centauri the star of the show

Located some 800 light-years away in the constellation Vela the Sails, the Vela supernova remnant is what remains of a massive star that exploded more than 11,000 years ago, blasting its outer layers into space. As those layers ram into surrounding clouds of gas and dust, they glow. Photo: MPAS member Nik Axaris

The most impressive sight when looking up this month 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 bright star Acrux, or Alpha Crucis, is a multiple star in Crux that can be resolved by a small telescope. The galaxy M83, also known as the Southern Pinwheel, is an excellent large-aperture telescope object in Hydra. But the real star of the show is the stunning globular cluster NGC 5139, Omega Centauri, in the constellation Centaurus. A small telescope reveals many of its millions of stars.

It is also the perfect time of the year for observing the dark nebula known as the Coalsack, which is visible to the naked eye and sitting right next to Crux, aka the Southern Cross. The Coalsack appears dark because it stops the light from the stars behind it from getting to our eyes. Then not far from the Coalsack you will find the wonderful open cluster NGC 4755, the Jewel Box Cluster. It looks like a hazy star to the naked eye, but binoculars or a small telescope will reveal its individual, colourful twinkling stars. If you are observing with binoculars, make sure you do not miss two marvellous sights in the nearby constellation Carina: IC 2602, the Southern Pleiades; and NGC 3372, the Carina Nebula.

Mercury will be at its highest altitude in the evening sky on April 9, then at its greatest elongation east a few days later on April 12, which means it is at its farthest distance from the sun.

And there are two meteor showers in April. The Lyrids reach their peak on the night of April 21-22, when you can expect to see an average of 10 meteors an hour in dark, clear skies. Then the Puppid meteor shower will be producing its peak rate of meteors around April 24. No special equipment or a lot of skill is required to view a meteor shower. All you really need is a clear sky and lots of patience. For optimum viewing, find a secluded spot away from the city lights. Once you have found your viewing spot, make sure you are comfortable, especially if you plan to stay out long – meteor-watching can be a waiting game!

By Nerida Langcake
This article appeared in the April 2023 issue of the Mornington Peninsula Magazine.