By Mike Lynch
I love hanging holiday lights all over the outside of my house. I don’t have as many lights as Chevy Chase had in “National Lampoon Christmas Vacation,” but I do have a lit up star on a pole on top of my garage.
The night sky over Everett has a touch of Chevy Chase with all the bright stars and constellations of winter, such as Orion the Hunter and Gemini the Twins. This year we also have the extremely bright planet Jupiter among them, the closest it’s been to Earth in more than a year.
If you happen to get a telescope for Christmas make Jupiter one of your targets with its four brightest moons and the cloud bands that stripe the disk of the largest planet of our solar system. Just make sure to let your telescope and all its eyepieces sit outside at least a half-hour before you use it so the optics can adapt to the cold. Otherwise you get some really funky images.
There really aren’t any constellations or constellation stories that have much to do with Christmas. Most of the names and stories we know of for constellations around here involve early Greek and Roman mythology. The gods and goddesses never got into the holiday spirit and so there’s not much celestial mistletoe and holly.
There is however a miniature but distinct symbol of the holiday season in the eastern sky, but you have to dig for it a little bit. It’s called the Christmas Tree Cluster because that’s exactly what it looks like.
You’ll need binoculars or a small telescope and you’ll have to wait until after 8:30 or so for it to be high enough above the eastern horizon. It might take a little work to find the Christmas tree cluster.
It resides in a very obscure constellation called Monoceros the Unicorn. It’s just so faint and undefined, it’s best to use the bright constellation Orion the Hunter, perched diagonally in the southeastern sky. That’s the dominant constellation of winter with the three bright stars in a nearly perfect row that make up the belt of the mighty hunter.
On the upper left corner of Orion a bright reddish tinged star called Betelgeuse marks the armpit of the hunter. On the upper right corner of Orion is the star Bellatrix, not quite as bright as Betelgeuse. Draw a line from Bellatrix to Betelgeuse and continue that line to the lower left about 10 degrees from Betelgeuse (about the width of your fist at arm’s length.).
Scan that area with your binoculars or telescope, and you should find the Christmas Tree Cluster. This is a great week to find it because there isn’t much moonlight.
Once you spot it you’ll see that the 20 or so stars are arranged in the shape of Christmas tree with a couple of brighter stars that mark the top of the tree. The starry little tree will appear to point to the right in binoculars but in most telescopes it’ll appear to point left since the optics in most telescopes give you an inverted view of the heavens. It’s brightest star is actually at the base of the tree.
The Christmas tree shape of the cluster is arguably a pleasant coincidence. The stars just happened to be arranged that way in our view from Earth. Like most open clusters this group of young stars formed out of the large nebula of hydrogen gas, much like our sun did over five billion years ago. These clusters of young stars hang out together for several hundred million years until gravity from other surrounding stars breaks them up.
This Christmas tree cluster astronomically bids tiding of joy from a long ways away at moare than 2,600 light-years, with one light-year equaling almost 6 trillion miles.
Mike Lynch is an astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, “Washington Starwatch,” available at bookstores. Check his website, www.lynchandthestars.com.
The Everett Astronomical Society: www.everettastro.org/.