Wheeled by Earth’s rotation, stars leave arc-shaped trails as they rise in the eastern sky last night. Details: 11 minute time exposure with a 24mm lens at f/2.8 at ISO 400. Photo: Bob King
While last night’s clear sky was perfect for stargazing, it would have been even better to have shared it with my friends at the Chippewa Valley Astronomical Society. They’re hosting the annual Starfest weekend from their observatory near Eau Claire, Wisconsin. Work precludes that possibility but I just want to say a big "Hi!" to all you guys. I know you’re sitting down by now to blueberry pancakes and sausages after a night that knew no sleep. Tonight looks like another clear one and I’ll be out there in spirit with you.
The sky really was fantastic Friday night — my gosh, the Milky Way looked like a lighted ski trail. I was poking around in the eastern sky with my binoculars and spent some time browsing the cluster-rich constellation Cassiopeia. We keep returning to the famous W for several reasons:
* It’s bright and has an easy shape to recognize.
* Within its borders are dozens of star clusters for binoculars and telescopes.
* You can use the W to point you to other interesting places.
Cassiopeia the Queen is an obvious W-shaped pattern of stars about three fists high in the northeastern sky at nightfall. With binoculars, drop down below the left side of Cass to spot the Double Cluster. The "E.T" cluster — named after the alien in the movie E.T. — is a misty patch touching a bright star immediately below the W. The top half of the W will point you to the Andromeda Galaxy which is 1-2 outstretched fists to the right. The best time for viewing these delicacies is from 10 o’clock on. Photo: Bob King
We’ve visited the Double Cluster in Perseus the Hero in a past blog. You can see this double dose of starry richness with your naked eye as puffy patch just below the left side of the W. Binoculars begin to resolve each cluster into individual stars. Very pretty! Now point your binoculars to the star just below the middle of the W as shown on the map above. If you look closely, you’ll see a delicate mist or spray of stars called NGC 457. This star cluster is better known as the "E.T" cluster because through a small telescope its two brightest stars look like extraterrestrial "eyes" staring back at the observer. The bulk of the cluster forms a sort of alien torso while two spindly arms of stars seem to reach right out into space on either side of the creature. E.T. is 9000 light years from Earth and contains at least 100 stars.
Can you see the alien in NGC 457? The two stars at top form the eyes and the arms reach out to the left and right. This is how the cluster appears in a modest-sized reflecting telescope. Another nickname for NGC 457 is the Owl Cluster. It’s an eye thing. Credit: Henryk Kowalewski
Finally, if you imagine the top three stars of the W as an arrow, it will point you straight down and over to the Andromeda Galaxy. What looks like a spoonful of Milky Way to your eye is 2.5 million light years away, the farthest most of us can see without optical aid. Even from a city’s outer suburbs Andromeda is visible on a moonless night, and from the country the galaxy jumps right into your arms once found. Binoculars will expand its size to at least four full moon diameters and reveal a bright, compact center where most of the galaxy’s starlight is concentrated. Don’t expect to resolve Andromeda into stars anytime soon. Even in big scopes, the galaxy remains as smooth and amorphous as fog.
The Andromeda Galaxy and two of it companion galaxies, NGC 206 (directly below) and M32, the bright spot at the 9 o’clock position from the center. Andromeda is similiar in size to our own Milky Way galaxy. Credit: John Lanoue
We’ll be stopping by the Andromeda Galaxy again this fall as it climbs ever higher in the evening sky. Meanwhile, back to enjoying the fine day ahead.
