Hey, Sky Fans! Scott here. Happy Monday. I hope everyone had a good weekend. It’s been a tough few days. I hope you’re getting by.
I’m late today, but the meetings are done, Al Green is on the hi-fi, and the coffee is fresh and hot. So, at long last…
Did you see the Moon and Jupiter on Saturday? The skies here were clear and beautiful. A couple of people in the neighborhood were out and feeling chatty. Alignments like those are always wonderful on their own. When you stop to think, and have a chance to talk with other people about what we’re really looking at it, two of our closest neighbors along the same line of sight, wow… I always get a great sense of place from it.
As I turned to come inside, I looked around for a few other stars, and snapped this shot of the southeast’s sky with my little pocket click-o-cam set for 15 seconds at ISO400. Someone was kind enough to label the sky right when I had the shutter open. Here’s a non-emboxified version.
Sort of in the middle, you can see one of my favorite stars: orange Arcturus, the brightest star in the constellation Boötes, the herdsman. It’s fourth brightest in the entire night sky, and the second brightest visible here in the northern half of the Earth. Do you know the other three?
Once you’ve followed the arc of the Big Dipper’s handle to Arcturus, you’re in a part of the sky that doesn’t have a lot going on, so Arcturus really stands out.
You want astroexcitement? I’ll give you astroexcitement. The root of Arcturus’s name, arc, comes from Greek, and means “guardian of the bear.” It refers to Ursa Major, the great bear, which is in the northern sky. In turn, arc is the root of the word Arctic, itself an allusion to Ursa Major. Right, so, Arcturus guards Ursa Major, and by extension, the entire north, from all the frightening miscellany a giant astronomical bear can’t protect itself from.
It’s an old star; a red giant, about 36 light years (LY) away. If you’re at that part of your life, you’re looking at light that left it right around when you were born. Meanwhile, the good people living there are only now getting their first glimpses of Indiana Jones in Raiders of the Lost Ark, mere minutes after they saw Han Solo frozen in carbonite.
If you can, try to imagine that distance. Think of all of the things you’ve been through in that time, while those photons have silently and patiently made their way through space for their one shot, their one chance, at your eye. And 36 LY years isn’t even very far as these things go!
Red giants like Arcturus are similar to the type of star our own Sun will turn into billions of years from now, as it cooks through its hydrogen fuel. It’s a bit of a stretch, but, in some way, looking at it is like looking at our own future.
In the box, you can see a friendly, almost-complete circle of stars. That’s another small and easy constellation, Corona Borealis, the northern crown. We’ve talked a bunch about some of the great, smaller constellations, and here’s another for your collection.
Corona, which is even smaller than Corvus, is about 20 degrees — the width of both of your fists held out at arm’s length — to the left of Arcturus, at the moment. The rest of the crown curves out behind the moderately bright double star, Alphecca, in both directions. Keep an eye on that group of stars as the summer goes on. You’ll see it slowly rise higher and higher through the night. Watch it rotate and move above Arcturus, following it to the horizon. By late July, it’ll be shining high in the southwest by mid-evening.
Scorpius, certainly stunning, always gets the summertime press. For my dime, the smaller and dimmer Corona Borealis, is at least as great a place to spend summer nights. I hope you’ll try it on (get it… crown… you can wear… sigh…)
Clear skies, everyone!