April: Magnificent arc shows the Way

Flame Nebula – Photo by MPAS member Steven Mohr

As the skies get dark this month you will notice that the constellations scattered along the arc of the Milky Way come into view. Crux, also known as the Southern Cross, and Centaurus, with the bright stars Rigil Kentaurus and Hadar – or Alpha Centauri and Beta Centauri – are on show. In the southeast, do not miss the bright star Antares in Scorpius. On the opposite side of the sky you will see Canopus in Carina.

There is relatively little going on in the sky overhead because this area is dominated by the long and winding constellation Hydra. However, you will find the bright star Spica in Virgo high in the east. 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.

By far the most impressive sight 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 – Alpha Crucis – in Crux is a multiple star that can be resolved by a small telescope. The galaxy M83, also known as the Southern Pinwheel, in Hydra is an excellent large-aperture telescope object.

For the early risers, April 7 will see Saturn near the waning moon in the morning sky, with Jupiter near the crescent moon the next morning. Then at 1am on April 28 there will be a perigee full moon, which is the moon’s closest point to Earth in its monthly orbit.

By Nerida Langcake
This article appeared in the April 2021 issue of the Mornington Peninsula Magazine.