Besides the big and little dogs (Canis Major and Canis Minor) there’s another pair of hounds in the night sky called Canes Venatici. Let’s pronounce that once — KAY-neez veh-NA-teh-si. It rhymes with the improbably “Hey knees, try not to sigh.” Böotes the Herdsman holds the eager dogs on a leash that dangles below the handle of the Big Dipper.
If there were ever a constellation that represents more figures with the fewest stars this is it. It has but two — Cor Caroli (the brightest) and Chara, second brightest and a Greek word that means “joy.” Both belong to the more southerly of the two dogs. The northern dog is comprised of stars too dim for most of us to notice.
Finding the constellation is super easy. Look high up in the northeastern sky as soon as it gets dark and locate the familiar form of the Big Dipper, the brightest part of Ursa Major the Great Bear. A little more than one fist to the right of the star at the end of the handle you’ll spot Cor Caroli, the “alpha” star in the hunting dogs. It’s a little fainter than the Dipper stars and appears single with the naked eye but put a small telescope on it, and this hidden gem becomes one of the most beautiful double stars in the heavens. 50x will give a fantastic view of not one but two suns in orbit about the other.
Directly above Cor Caroli you’ll see a fainter star, Chara. Connect the two stars with an imaginary line and that’s it — you now have the entire constellation. Once found you’ll see Canes Venatici routinely because it’s right next to the Dipper. Dogs may be difficult to picture among its sparse stars. Instead imagine a stick you might throw to a dog to play fetch.
While the constellation lacks visual pizzazz it’s home to two of the most stunning sights in the sky, the globular cluster M3 and the Whirlpool Galaxy, also known as M51. The “M” stands for Messier, as in Charles Messier, the 18th century French astronomer who first cataloged many of the brightest and best known clusters, nebulae and galaxies. Both of these objects are faintly visible in a pair of 7×50 or 10×50 binoculars from country skies but best appreciated in a telescope. Or just enjoy the pictures!
M3 is a gigantic, globe-shaped collection of half a million stars 33,900 light years away that orbits the Milky Way Galaxy far above its plane. The fact that you can see it in binoculars a third of the way across the galaxy testifies to cluster’s “star power”. We’re used to thinking that the solar system is extremely ancient with an age of 4.5 billion years, but M3’s suns are more than twice as old. They formed 11.4 billion years ago when the galaxy itself was only getting its legs. Like a hallowed tree that raises its gnarled branches over a changing landscape this starry sentinel has witnessed much in its lifetime.
Many of the cluster’s brightest stars are red giants and easily visible in the photo. Red giants are evolved versions of our sun that have blown up like balloons in their old age. The sun will do the same in about 5.4 billion years when it too becomes a red giant, just one stage in its long evolution.
You’ll find the cluster easily enough. It’s located about halfway along a line from Cor Caroli to Arcturus. A 6-inch telescope will reveal a fuzzy, bright core surrounded by faint tentacles of stars reaching in all directions. Larger telescope give incredible views, making the globular look like a hoard of spilled jewels.
Canes Venatici’s other little secret is the magnificent Whirlpool Galaxy. Named for its shape, the Whirlpool hails from about 23 million light years away. Like the Milky Way it’s classified as a spiral galaxy but smaller with a diameter only 43 percent as large and possessing far fewer stars. When you buy a telescope this is the galaxy many of us cut our teeth on when it comes to seeing spiral arms. While galaxies show tremendous detail in photographs features even large features like spiral arms can be elusive. A 6-inch scope will begin to show the brighter whorls but you’ll need at least an 8-inch instrument to detect the full whirlpool and the nearby galaxy NGC 5195. When the arms materialize through the eyepiece the sight will make you cry. It really is that beautiful.
M51 is the showpiece of a meek constellation and one of the approximately 2 trillion galaxies that populate our unimaginably rich universe.