May: Constellations, clusters and conjunctions

NGC 6334, the Cat’s Paw Nebula, is an emission nebula and star-forming region located about 5500 light-years from Earth in the constellation Scorpius. The stars created here would be 10 times the mass of our sun. The nebula is in the Carina-Sagittarius Arm of the Milky Way. Photo: MPAS member Chris Kostokanellis

In the southern hemisphere this month you will be treated to the richness of the constellations Centaurus, Scorpius and Sagittarius. The Milky Way rises high in the south, with Sagittarius and Scorpius sitting in the east. The large constellation Centaurus, the Centaur, sits within the stunning star fields of the Milky Way. Looking south to Carina, the magnitude 3.8 open cluster NGC 2516 sits roughly 3.5 degrees away from the star Avior, or Epsilon Carinae. It contains about 100 stars and can be viewed with just a pair of binoculars.

In the east, several star clusters are on view in the constellation Ophiuchus this month. Besides the globular clusters M12 and M10, which are both prime targets for a small telescope, there is the magnitude 4.6 open cluster NGC 6633, which is roughly the same size in the sky as the moon. Composed of 30 stars, this open cluster is a wonderful sight through a small telescope. Northwest of NGC 6633 is another large and scattered open cluster, IC 4665, which lies close to the Cebalrai, or Beta Ophiuchi, and is easily visible with binoculars.

This year the annual Eta Aquariid meteor shower peaks around May 6-7. It is caused by the dust left over from Halley’s Comet entering our atmosphere and vaporising, and you can expect to see roughly 30 meteors an hour if you are 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 further south you are, the better view of the shower you will get.

A conjunction is when two astronomical objects appear close to each other in the sky, and there are quite a few to see this month. On May 1 is the conjunction of Venus and Jupiter, May 22 the moon and Saturn, May 25 the moon and Jupiter, May 27 the moon and Venus, and May 29 the conjunction of Jupiter and Mars.

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