Next week's full moon is a great time to start lookng for two of the brightest stars, writes Ian Griffin.
Summer is on the way. I know this because not only are warm temperatures being forecast for this week, but also because I managed to spot the distinctive pattern of stars which makes up the constellation Orion rising over Portobello harbour while taking Connie, my springer spaniel, for a late-night walk last weekend.
The moon is full on Saturday, which means that bright moonlight will wash out the dimmer stars for most of the next week. While the period around full moon is not great for those of us who enjoy tracking down dim galaxies, it is an excellent time to get a head start on locating the two brightest stars in the sky.
As our chart shows, Orion is rising in the east just before midnight. By midnight this week, the giant red star Betelgeuse, which marks the hunter's shoulder, is just over five degrees high (the same angle subtended by your three middle fingers held at arm's length), while at the other end of the constellation, the bright blue giant star Rigel (called Puaka by Maori) will stand some 25 degrees above the eastern horizon.
If you manage to pick out Betelgeuse, casting your gaze to the left and slightly upwards reveals the lovely orange-red star Aldebaran in the constellation of Taurus the Bull, with the distinct pattern of Matariki close by.
If you want to find the brightest star in the sky (other than the sun), there is a really easy way to do it using Orion's stars as helpful guides.
Just draw an imaginary line through the three bright stars which make up the hunter's belt and extend it to the right, where it will eventually reach an unmistakably bright blue-white star. This is Sirius (called Takurua by Maori).
We can also use stars of Orion to help us find Canopus (called Atutahi by Maori), which is the second-brightest star in the sky. If you draw another imaginary line starting at Betelgeuse, towards the star Saiph and then continue that line in the sky, you will eventually reach Canopus.
