Hunter on the prowl, so tighten your belt

AS the summer begins — astronomically, it began at the moment of the solstice in the small hours of yesterday morning — the warmer nights tempt us to spend more time looking at the night sky.

Unfortunately, the late summer sunset, together with the hour of daylight saving, means that we have to wait until quite late in the evening to achieve our aim.

Tasmania has the longest summer days of any state, because we are the farthest south — and, of course, that means the shortest nights, too. With the sun setting about 8.50pm (summer time), the sky is not really dark until about 10.30pm. However, do go outside and take a look around.

When I was first finding my way around the starry night sky from the garden of the family home in Sandy Bay, one of the earliest star patterns I learned to recognise was the constellation of Orion, The Hunter. It is visible tonight towards the northeast.

The easiest way to find him is to look for the three bright stars in a row. They mark Orion’s belt, and are also known as the “Three Sisters’’.

Well above the belt are the two bright stars that mark his legs, and down below are those that mark his shoulders. The lower of the two “shoulder’’ stars — the one on the right — has a distinctive reddishorange colour. It is the star called Betelgeuse, often pronounced “beetlejuice’’, although its correct pronunciation is more like “bettlejooz’’. Betelgeuse is a red supergiant star that will explode soon — probably some time over the next million years.

Not far above Orion’s belt, you will see what appear to be three little stars in a row, much closer together than the belt stars and in a line at roughly a right angle to them. This is Orion’s sword, which dangles upwards from his belt for us in the southern hemisphere. The middle one of these appears to be rather “fuzzy’’. It is the famous Orion nebula, a cloud of gas and dust in space where stars are being formed. It is the most famous nebula in the sky, and you can see it more clearly using a pair of binoculars. Maybe Santa has been able to provide you with a pair!

If you make a quarter turn to your right, you will see the most famous of the constellations for us in Australia: Crux Australis, better known as the Southern Cross. However, you’ll notice that it’s nearly upside down, even for us, during the evenings at this time of the year. The famous “pointer’’ stars are to the right of the cross and a little lower down.

As the night progresses, you will become more aware of the glow of the Milky Way stretching from near Orion to the south, passing right through the Southern Cross.

You’ll be more likely to see it clearly if you are well away from the troublesome city lights, and with the moon steadily brightening at the moment, it’s a little harder to see than if the sky were perfectly dark.

The moon is a great feature of our evening sky this Christmas, being at the phase we call first quarter. This time in its cycle of phases is great for evening observation of the moon with binoculars and small telescopes, which reveal many of its craters and mountains.

However, you may ask: What about the “Christmas Star’’?

At the Planetarium, we are often asked about this as we approach the festive season. There have been many

Space

attempts to find an astronomical explanation for this famous biblical object, and if you are up in the twilit hours before sunrise, you may be tempted to identify it with the very bright object in the eastern morning sky. However, this is the planet Jupiter, with the Red Planet, Mars, seen just above Jupiter and to its left.

Enjoy the warm summer nights, and I wish you all the very best for Christmas.

Next week, we’ll have a preview of some exciting things to come in 2018.