Lovejoy gets kinky. In this photo taken January 8th, the comet’s tail is caught in the act of separated from the head or coma. Magnetic fields embedded in the stream of particles from the Sun occasionally reconnect on the rear side of a comet and pinch off its tail. Credit: Rolando Ligustri
Looks like Comet Lovejoy got its locks trimmed again. A flutter of solar wind swung round the comet and pinched off its tail, an event captured in the dramatic photo above. You can already see a new tail growing in place.
The solar wind, a dilute stream of electrons and protons blown free of the Sun, wafts across the solar system and touches everything from the biggest planet to the smallest comet.
An ion or gas tail like the one in the photo forms when cometary gases, primarily carbon monoxide, are ionized by solar radiation and lose an electron to become positively charged. Once “electrified”, they can be twisted, kinked and even snapped off by magnetic fields embedded in the Sun’s particle wind.
Having passed closest to the Earth on January 7th, Comet Lovejoy is now high in the southeastern sky at nightfall and near its maximum brightness of 4th magnitude. It’s a little dim with the naked eye, but once you know where to look, I think you’ll be surprised how easy it stands out. At least from the less light-polluted outer suburban and rural areas.
If you can find Orion, you can find the comet. Use Betelgeuse and Rigel (above and below the constellation’s 3-star belt) to form a right triangle with Comet Lovejoy. Once you fix the spot with your eyes, you may see the comet directly. If not, just point your binoculars there and sweep around a bit. Source: Stellarium
I’ve been using bright stars in Orion and Taurus to first guide my binoculars – and then my eye – to the comet. It’s easy to use two bright stars, like Aldebaran and Betelgeuse, and extend a line from each to form a triangle with Lovejoy at one of the corners. If you then point binoculars at that spot in the sky, the comet should pop out. You can then lower the binoculars to see if you can spot it with your naked eye.
The map above is drawn just for tonight. Click HERE for a map showing the comet’s changing position through January 23rd.
A halo rings the bright moon and planet Jupiter (upper left of moon) Wednesday night. Ice crystals in high cirrostratus clouds bends or refracts moonlight into a circle of light. Credit: Bob King
Two nights ago, when I last looked at the comet, a bank of icy cirrostratus clouds moved in around moonrise and created a lovely halo around the moon and Jupiter. These familiar high, wispy clouds are composed of myriad six-sided ice crystals resembling the cells in a honeycomb. Light entering one side of the crystal is refracted or bent out another side. Add up billions of these tiny bits of bent light and they to form a circle around the Sun or moon called a 22-degree halo. The number indicates the radius of the halo or distance from the moon to the edge.
The Sun rises over a “steamy” Lake Superior in Duluth this morning as seen through the window of a local hospital. Credit: Bob King
At the moment, a large swath of the U.S. is steeped in bitter cold air. That often means clear skies at night. Allow yourself at least 5-10 minutes to get your eyes used to the darkness and then another 5 hunting for the comet. If you plan it right, you can be in and out in 20 minutes!
Patches of iridescent colors glow near the Sun an hour after sunrise this morning. Light scattered or diffracted by the extremely small ice crystals in the clouds creates a full range of vivid colors. A single sundog glows at left from light refracted by ice crystals in lower clouds or perhaps within a frozen wisp of vapor rising from the lake. Credit: Bob King
In Duluth, Minn. this morning the temperature dipped to around -10F°. Whenever we go below zero, water vapor above warmer Lake Superior condenses in the chill air into curly wisps of fog locally known as “steam fog”. This made for a very pretty sunrise. If that wasn’t enough, high altocumulus clouds passed near the Sun shortly after sunup, creating a palette of delicious greens, reds and purples. We even had a solitary sundog appear for a few minutes in a different set of lower clouds composed of ice crystals.
A closer view of the Sun and the strikingly beautiful iridescence. Click to learn more about diffraction and iridescence. Credit: Bob King
What a treat for the eyes! My wife and I saw all this unfold from the window of one of the local hospitals where we’d gone for a routine procedure. Whenever light puts on a show like it did this morning, I always tell myself I really need to get up earlier to catch more sunrises. And pack something a bit higher-end than a mobile phone!