Canes Venatici — A Nothing Constellation With A Surprise Or Two

Polish astronomer Johannes Hevelius created the constellation Canes Venatici in 1687 from several loose stars near the end of the Big Dipper’s handle. The dogs strain at the leash, eager to chase after the Great Bear Ursa Major (at right). Urania’s Mirror / William Jamieson

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.

Just find the Big Dipper and you’re on to Canes Venatici, represented by its two modestly bright stars, Cor Caroli, and Chara. Stellarium

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.

M3 looks like a small ball of haze in binoculars but it’s 180 light years across and contains some 500,000 stars. Globular clusters are spherical collections of stars held together by their own gravity located our galaxy’s outer halo. M3 was the first object discovered by astronomer Charles Messier that ended up in catalog of 110 objects. Jim Misti

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.

If you’d like to try and find either of the hunting dogs’ this map will help you get there. M3 is about halfway between Arcturus and Cor Caroli while the Whirlpool Galaxy lies 3.5° from the end star (Alkaid) of the Big Dipper’s handle. Stellarium

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.

M51 or the Whirlpool Galaxy is a superb example of a spiral galaxy seen face-on. Astronomers think that gravitational tugs from the smaller galaxy at right have helped to sharply define the Whirlpool’s spiral arms. The dark material that lines the inner edges of the spiral arms is made of star dust, some of which is being compressed by gravity into new star clusters — the pink spots. Jim Misti

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.

 

 

5 Responses

  1. Edward M Boll

    I’ll have to look at these. Since the Moon travels at about 12 degrees a day. I call within half of that a conjunction. Finally after a few weeks of Jupiter and Saturn conjuncting with Mars, the conju nction is over. But now comes Jupiter and Saturn. These 2 will be 6 degrees from each other or less for nearly a year and a half. Comet Y4 may have faded again just a bit. Most observations put it between magnitude 9 and 10. If it were brightening at average it might still be something to be in awe of. My brightest hope now is that when it was near magnitude 7, it was in outburst and will now act normal, but from what I have read, this is probably not the case.

  2. Edward M Boll

    New Swan Comet discovery. Magnitude 10 now, about the same as Atlas. Swan now deep in the south is expected to move north rapidly by mid May possibly as a nice placed binocular comet . Perihelion seems to be fairly close to the Sun. I do not have the exact coordinates as this new comet was announced on Friday. I hope this one does not disappoint. If so, it would be a small consolation for the possible future loss of Atlas.

    1. astrobob

      Edward,
      Cross your fingers. I observed ATLAS last night. My, how it’s changed. It’s still largish with a 5 minute coma and magnitude 9.5 but much less condensed. The nuclear region is fascinating now — clearly elongated with at least two condensations, but they’re difficult to discern. Best at 357x. The Swan filter still improves contrast and fattens the coma by an additional arc minute.

  3. Edward M Boll

    Yes, I ought to try for it but I’m thinking it will be so faint that I won’t know if I have it in view for sure. Most now recorded obversations are now with over 50 magnification.

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