It’s been an exciting week with the return of Comet Catalina to the morning sky. I got my first frozen fingers of the winter season standing along the shore of Lake Superior adjusting camera settings trying to get a photo of the comet. As I write this, the cold is forgotten. What remains is the memory of seeing Venus reflected in the wavy water and the beauty of the zodiacal light, a huge cloud of desiccated comet and asteroid dust, rising from the wet lake.
A growing number of skywatchers have spotted the comet in binoculars and telescope with at least one naked eye report. Magnitude (brightness) estimates vary, but most fall around magnitude +6, right at the naked eye limit. I saw it faintly Sunday in binoculars very low in the southeastern sky. Had it been clear this morning, Catalina would have been an easier target because it’s since climbed higher in the sky.
Michael Jaeger’s image of Comet Catalina is one of the best I’ve seen so far. If you look very carefully, you can see three tails. The blue-hued ion or gas tail pokes out to the right (northwest) of the gaseous green coma; a prominent Type III dust tail extends to the lower left (S.East) and a classic but very stubby Type II dust tail fluffs out between them closer to the gas tail. Carbon monoxide fluorescing in the sun’s ultraviolet light gives the gas tail its distinctive blue color. The Type II tail consists of dust particles released by the comet during perihelion on Nov. 15th when it was closest to the sun, while the bigger dust tail is composed of larger dust chunks released before perihelion.
According to Australian comet observer Michael Mattiazzo, the angle of separation between ion tail and dust trail will remain this way
until after Catalina swings closest to Earth in mid-January. Thereafter the “fan” will close to 90° in late January.
I love the moon, but tonight it’s full and brightens both evening and morning skies, making it harder to see the comet for a time. In a week, when with its phase has whittled to half, the morning sky will be darker, the comet higher and views much improved. I still encourage you to give it a go if you’re game. Head out about 2 hours before sunrise, when Catalina will be highest in the sky. Use the map to help you pinpoint its location; you’ll need at least 50mm binoculars (7×50 or 10×50) or a small telescope to see it in a moonlit sky. By the way, the comet will pass only a minutes of arc (fraction of a degree) SE of the 4th magnitude star Lambda Virginis on Friday morning the 27th. Find the star and you’ll see the fuzzy comet right next to it.
Yes, a Full Frost Moon. That’s what you can expect along with some real frost on the ground tonight provided the sky is clear. Watch for the moon to rise around sunset in the constellation Taurus the Bull. November’s full moon “rides high”, meaning it will climb to a high altitude and shine brilliantly from above around midnight. Seen so far up from the horizon haze and its scattering effects, the frost moon will shine hard white without a trace of the usual yellow tint when viewed lower in the sky.
Many of us have tomorrow off from work because it’s Thanksgiving. That means it doesn’t matter if you lose a smidge of sleep tonight, right? Great! Because the full moon will cover the Taurus’s brightest star, 1st magnitude Aldebaran, tomorrow morning for skywatchers across Canada and much of the U.S. Timing’s a killer — the event happens around 4:30 a.m. CST (5:30 a.m EST, 3:30 a.m. MST, 2:30 a.m. PST) — but the smallest of telescopes and maybe even a pair of 7×35 or 7×50 binoculars will show the orange-red star suddenly blink out as it’s occulted by the left edge of the moon.
About an hour later, as the moon moves eastward in its orbit, Aldebaran will blink back into view along the moon’s opposite limb. Check out Bob Moler’s blog for a coverage map. The best way to figure out exactly when the moon will cover Aldebaran for your location is to download the free planetarium-style software program Stellarium. Once set up, under Sky and Viewing Options uncheck the Scale Moon box and set the star Relative size number to around 0.3 to obtain an accurate picture of the event.
There’s always a feast in the sky — Happy Thanksgiving!
