Observer’s Guide – May 2015
It’s a new month and here in the Southern Hemisphere we’re starting to enter into winter when the stargazing is at its best. Cold dry air, with the best the southern skies have to offer all neatly presented, capped off with a nice selection of planets throughout the night makes for what should be an excellent month.I say “should be” because the weather doesn’t seem to realise what’s expected of it. My home town’s rainy season should have stopped months ago, and it should long ago have become too cold to enjoy an evening drink outside in a T-shirt, but so far none of those things have happened. In my own observing sessions, seeing has been consistently bad. The atmosphere just never seems to settle down and all my photographs are low on detail and full of big fuzzy stars (and yes, I do double-check my focus!).
But let’s stay positive and get on with what attractions the May sky has to offer.
On the 4th, the Moon will be full, so this is a good time for deep sky observers to remember that not everything in space is a faint fuzzy: Check out Venus, Jupiter and Saturn, all of which are beautifully placed and bright enough to not care about the moonlight.
On the 5th of May, the Eta Aquariid meteor shower peaks. This is usually a good shower, with a zenith hourly rate of about 55 meteors per hour, but conditions will be far from ideal, with the Moon only a day past full. Still, if you’d like to give them a go, remember to get up at about 2am, bundle up extra warm and face east. Good luck!
On the 8th, between sunrise and sunset, the Moon will be threading the needle between several open clusters north of Sagittarius, including M23 and M25. Depending on your location, you might even catch a cluster occultation (although at 85% illumination, the individual stars will be hard to spot).
Still with open clusters, Venus will pass very close by M35 in Gemini on the 10th and 11th. Venus is heading back towards the Sun at this stage, so head out early in the evening with binoculars to spot this. The Moon will be at last quarter on the 11th, so plan your deep sky observations for before midnight.
Somewhere around the 13th, comet C/2015 G2 Master will round the Sun and start to appear in the evening sky. Over the rest of the month it will move from Fornax to Lepus to Sirius to Monoceros, never getting very high above the early evening horizon and should be visible in binoculars.
On the 18th, the Moon will be new and the skies will be as dark as light pollution allows. Shallow sky observers: now’s the time to break out of your comfort zone and look for some of those faint fuzzies!
Two days later, on the 20th, a thin crescent of a Moon will pass near by the open cluster M35 above the north west horizon for southern hemisphere observers. This might be a nice photo opportunity.
The 20th and 21st are good for planet watchers. First, both Io and Ganymede will cast their shadows across Jupiter’s surface, between 22h04 and 22h33 UT. And the following evening the other two moons (Europa and Callisto) get their chance between 11h26 and 11h59 UT.
And finally, on the 25th, the Moon will be at first quarter, passing near Regulus in Leo.
As always, feel free to share your observations in the comments below!