Our Star Charts are updated monthly. Keep checking back here for the latest guide to the stars above.
DOWNLOADABLE STAR CHARTS
Star Chart for April 2015 – Western Sky
Star Chart for April 2015 – Eastern Sky
Star Chart for May 2015 – Western Sky
Star Chart for May 2015 – Eastern Sky
AUTUMN SKY GUIDE
MARCH 2015 I APRIL 2015 I MAY 2015
As the Earth tilts to a new season, a new set of constellations appear in the night sky. The zodiac constellations feature strongly in this period with Gemini, Cancer, Leo, Virgo, Libra, Scorpius, and Sagittarius all making an appearance.
By mid April the sky has moved around and the summer landmark, Orion, is now setting in the early evening followed soon after by the ‘Dog Star’, Sirius. Looking north, there are a series of zodiac constellations with familiar names dating back to antiquity.
From west to east we can see Gemini, marked by the two bright stars, Pollux and Castor. Cancer though is quite inconspicuous and hard to pick out if you are competing with city lights or bright moonlight.
On the other hand, Leo, the next constellation moving eastwards, is easy to pick out because of its bright, orange star, Regulus. East of Leo is Virgo, easily identified by its bright star, Spica. Spica is brilliantly white, which means it’s very hot, much hotter than our Sun. Near to Spica there is a conspicuous quadrilateral marked by four stars forming a handy signpost – the constellation of Corvus (the Crow). This procession of zodiac constellations will cross the northern sky from east to west as the night goes on, followed later by Libra, Scorpius and Sagittarius. In the southern sky, the key landmark to locate is Crux (The Southern Cross) the iconic constellation of the Southern Hemisphere. At this time of year, face south and look up high and you should pick it out without difficulty. Just to be sure, check that the two bright stars of Centaurus (commonly called ‘the Pointers’) are pointing to the top of the Cross.
Following an imaginary line up the sky from the Pointers, on through Crux, you will find the constellations of Carina, Vela and Puppis. There are a number of different patterns you will come to recognises here but most people notice the distinctive shape of the ‘False Cross’. It isn’t a constellation but it is so obvious that astronomers call it an asterism. It actually consists of two stars from Carina and two from Vela, all having roughly equal brightness. The brightest star in Carina is the brilliant Canopus. It is the second brightest star, second only to Sirius, and the most luminous star within 700 light-years.
Continuing our imaginary line beyond the False Cross, essentially following the centre line of the Milky Way, we find the large constellation of Puppis. While this isn’t a household name, it is quite bright and passes overhead in New Zealand.
This trio of important southern constellations – Carina, Vela and Puppis – once made up a single, huge constellation called Argo Narvis (being the mythical shop of Jason and the Argonauts). Argo Narvis was created in the 2nd century before being divided into smaller, more manageable constellations in the 17th century.
At this time, if you can see the autumn sky on a moonless night away from city lights, you can easily pick out the disk of our galaxy – the Milky Way. It looks like a ghostly cloud running from the south-eastern horizon passing through the Pointers, Crux, Carina, Vela and Puppis and on across the sky passing between Orion and Gemini in the north-west. This band of faint light is the combined light of some of the estimated 200 billion stars that make up our galaxy.
In early March Mercury is visible in the eastern sky just before dawn. Moving back towards the Sun it is soon lost in the glare. Mercury reappears in the western sky but is hard to spot near Mars and the Pleiades in early May.
Venus is low in the north-west after sunset during March but moving away from the Sun, it will become progressively more prominent in the north-western sky in the early evening into May. By late May it will be close to Pollux and Castor, the Gemini Twins.
From March through to May, Mars will be setting very soon after sunset and hard to see.
During March Jupiter can be seen after sunset, low in the north-east. It lies roughly midway between Regulus (Leo) and the Gemini Twins, Pollux and Castor. Jupiter, however, is actually in Cancer. By April, it is almost due north but only about a third of the way up the sky. Because Jupiter is so far north, we will not get the best telescopic views from the Southern Hemisphere. Still, even low in the sky, telescopes will still show many of its famous features. By mid-May it will be setting at around 11pm.
Saturn continues to rise earlier each night as autumn comes on. In mid-March it’s rising with Antares (Scorpius) just after midnight, changing the familiar pattern of this iconic constellation. In mid-April it is rising at 8pm and it reaches opposition to the Sun on 23 May, at which time it is rising as the Sun sets. This is the best time for telescopic observations of Saturn in 2015. In Auckland it reaches 71 degrees above the horizon by midnight and about 10 degrees lower in the far south of the country.