Constellations
As we approach autumn and winter, the summer constellations are on the wane and new ones loom into view. Now, in early September, is a great time to take a last look at Cygnus in the heart of the Milky Way and, if you want a real challenge, the zodiacal constellation of Sagittarius, with its Teapot asterism, low to the south. Then it’s time to move on to more seasonal targets.
Autumn is the time that the zodiacal constellations of Aquarius, Aries and Capricornus appear in the sky, along with some of the Perseus family: Andromeda, Cassiopeia, Cepheus, Cetus, Lacerta and Pegasus. Although Cassiopeia and Cepheus are circumpolar, so can be seen all year round, they’re particularly well placed at this time of the year. The unmistakable ‘W’ shape of Cassiopeia, rich in open clusters and emission nebulae, and the Great Square of Pegasus, with its beautiful globular cluster and galaxies, act as easy visual guides to their locations. And then there’s Andromeda, an enormous galaxy that lies between the two and also happens to be the most-distant object visible to the unaided eye.
As we move into winter, Perseus itself and family member Auriga become well placed. Both have beautiful open star clusters, while nearby is another family member, Triangulum, with its famous spiral galaxy. Cetus with its barred Seyfert galaxy and the zodiacal constellations of Pisces and Taurus are a clear reminder that winter is upon us. Taurus, the constellation of the Bull, is packed with beautiful open clusters, a supernova remnant and unmistakable ‘V’ shape. Orion and Gemini follow close behind. Orion is rich in nebulae and eagerly awaited as an imager’s paradise, while Gemini presents planetary nebulae, open clusters and emission nebulae.
In the New Year, look out for the Winter Triangle formed by the bright stars Procyon in Canis Minor, Sirius (the brightest star in the Northern Hemisphere) in Canis Major and Betelgeuse in Orion. Between Canis 0DMRU DQG &DQLV 0LQRU \RX OO QG 0RQRFHURV ZLWK its beautiful open clusters and several nebulae. Then as we approach spring, the zodiacal constellation of Cancer slides into an excellent observing position, bringing with it beautiful star clusters.