May: Omega Centauri a sight for your eyes

The Milky Way, with the gas giant Jupiter visible in the top left corner. Photo by MPAS member Tony Nightingale

Sitting high in the southern sky during May is the prominent constellation Crux, the Southern Cross. If you have a small telescope, be sure to point it at Crux’s brightest star Acrux, which is actually a double star made of two blue-white stars. Whether you are observing with the naked eye or a telescope, it is the globular cluster NGC 5139, Omega Centauri, you will want to set your sights on this month. You can see it easily as a hazy star with the naked eye, whereas a telescope reveals many of its millions of stars in a tight ball. If you have a large aperture telescope, turn it towards the fine spiral galaxy M83 that sits in the constellation Hydra.

The Milky Way rises high in the south this month, with Sagittarius and Scorpius sitting in the east – a clue that winter is on its way in the southern hemisphere.

Caused by the dust left over from Halley’s Comet entering our atmosphere and vaporising, the Eta Aquariid shower peaks every year around May 5-6. You can expect to see roughly 30 meteors an hour if you’re very lucky. The meteors appear to be coming from a point near the star Eta Aquarii in Aquarius, and tend to be quite fast-moving. The farther south you are, the better view of the shower you will get.

Looking up on May 12, the moon will be between Jupiter and Saturn in the evening sky. Then on May 15-16, Mars will be near the waning moon. On May 22, the planets Mercury and Venus will appear close, and May 24 will see a thin crescent moon near Venus.

By Nerida Langcake
This article appeared in the May 2020 issue of the Mornington Peninsula Magazine.