The Andromeda galaxy, Bode's nebula (actually a galaxy), and the beautiful Double Cluster in Perseus. We have discussed them all before, but this week we will take a special journey, hopping from one to another, in a dance across the sky.
We can take this tour of the heavens with any small backyard telescope, or even a pair of binoculars. If you are using a pair of binoculars, try to use a pair with a large objective (main lens). This is the second number written on a pair of binoculars, and 50mm or better is usually recommended for astronomy, although for this star hopping expedition, even a pair of 40mm binoculars will provide the light gathering ability needed. In fact, dark skies and a good pair of binoculars would be perfect for this week's transit of the sky.
The place we will start is the giant spiral galaxy, M81. This is also known as Bode's nebula. M81 is a gigantic galaxy, drawfing our own Milky Way galaxy. This galaxy looks much like our own, and has been shown to have active star formation occuring in it's spiral arms.
To find M81, first you need to find the north star. Now, imagine a line running from the north star, directly down to the northern horizon. Starting at the horizon, travel upwards, through the north star, until you are between 1/2 and 2/3 of the way above the horizon. M81 should be about here around 8pm. Look for it as a spiral galaxy, about magnitude 6.9 (about as bright as Neptune). It appears from Earth to be about 1/2 degree across, about the same as a full moon, or the Sun.
Bode's Nebula never sets, and can be seen by the backyard astronomer at any time. Objects of this type are known as circumpolar objects, due to their proximity to the North Star, Polaris.
Half of a degree away from M81 is the elongated spiral galaxy, M82. This is also known as NGC 3034. Only about 1/3 the apparent diameter of M81, it is also dimmer, at magnitude 8.4. It is still well within the ability of backyard telescopes or binoculars to see this object.
Now travel about 45 degrees to the west, and down to slightly under 1/2 way up from the horizon. This is our next stop, the Double Cluster. Under dark skies, you should be able to see the double cluster sitting 40 degrees above the western horizon around 8pm. It shines at magnitude 4, about as bright as comets get before they start to attract the attention of the general public. Also known as NGC 869, it is one of the most beautiful abjects in the sky. Both of these clusters are open clusters; loose, graviatationally bound families of perhaps 10,000 stars each.
There is little star production in open clusters, and so most of these stars are very old. One consequence of this is that there is little material other than hydrogen and helium in these star clusters, so the chances of rocky, Earth-like planets here are small.
Finally, turn your gaze towards the west/northwest, and set your sights 18 degrees above the horizon. Shining at magnitude 3.5, here lies M31, the Andromeda galaxy. This is the most distant object visible to the naked eye. Long thought to be an impressive 2.3 million light years away, recent measurements from the Hipparchos satellite measure the distance to M31 at an even more stunning 2.9 million light years away. The Andromeda galaxy is much like our own Milky way galaxy, only a little larger. One of the most impressive things about viewing M31, is that it appears from Earth to be nearly three degrees across, the same as six full moons put side by side.
Clear skies, and good viewing.
Jim Maynard is the head of the astronomy department at Earth Treasures and has been an amateur astronomer for more than 20 years. He is a physics student at Keene State College and leads star parties at Wheelock Park in Keene, New Hampshire. If you have any questions about astronomy or star gazing, call him at 603-352-7192. Shop for telescopes and accessories at More About The Solar System: A primer Back To Starwatch Index Enter keywords...
Jim Maynard is the head of the astronomy department at Earth Treasures and has been an amateur astronomer for more than 20 years. He is a physics student at Keene State College and leads star parties at Wheelock Park in Keene, New Hampshire. If you have any questions about astronomy or star gazing, call him at 603-352-7192.
Shop for telescopes and accessories at
More About The Solar System: A primer
Back To Starwatch Index
Enter keywords...
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