During our local astronomy club meeting last week, someone shared a recent picture of comet Pan-STARRS C/2011 L4, and I thought “Hey. I thought that comet was long gone! Maybe I should write an update on the comets.”
I discovered that L4 is still viewable in telescopes larger than 4” at a +11 magnitude, and photographing it reveals an amazing tail. An ion tail and a dust tail are clearly visible, while an anti-tail is pointing in the opposite direction towards the sun. I hadn’t heard of anti-tails, but apparently they form when the pressure of sunlight blows fresh dust back from the comet’s head.
In the meantime, ISON is currently streaking towards us at a leisurely 50,351 mph. Touted as possibly the brightest thing since sliced bread, ISON may not put on the show that everyone promised. It stopped brightening at the beginning of this year and has stagnated around +16 magnitude. Although it briefly sprouted a bright tail, the coma faded and became smaller and less condensed.
Everyone is still waiting to see just what kind of show ISON will put on, and we’ll know the answer to that around November 10 when ISON is expected to be visible to the naked eye. All we can do now is keep our finger’s crossed.
Our good friend Tony was out stargazing last week and sent us these spectacular pictures of Pan-STARRS (Comet C/2011 L4).
When Amy and I were at our club’s Messier Marathon this past weekend, some club members were showing off recent pictures of the comet, and it occurred to Amy and I that we should really get out and take another look at it before it’s gone.
Tony reports that the comet was still visible in binoculars last Thursday (4/4/13), and that he and a couple of other club members were able to view the comet with the tail and M31 at the same time using wider field binoculars.
He also reports that the comet is now about 20 degrees above the horizon in the evening sky just as the sun sinks below the horizon, and is difficult to see because of the sky glow. He said that mornings are better here in Wisconsin, when the comet is up 15-20 degrees around 4:00 – 5:00 a.m.
But as Tony notes in his email, we need to have a morning soon when it isn’t either raining or snowing, and those days are few this time of year in Wisconsin. Just this early morning, we received at least three inches of new snow. I’m hoping that all this precipitation will actually bring those May flowers soon!
Yay!! Woo Hoo!!! Wooot woooot! After three days of snow and clouds, Wednesday night turned out to be our best bet for seeing comet Panstarrs. We finally had sunshine all day! I bee-lined it over to Lynn’s house right after work. She gathered up her warm clothes, grabbed a bite to eat and looked up the directions to Tony’s.
Do we feel guilty about missing a club meeting? Naah, we just HAD to see this comet! As we drove in rush hour traffic we could see the sun slowly sinking in the western sky. As each turn took us closer to our comet encounter, we got more and more excited. We knew this could be our only chance of seeing it! It seemed like we hit every red light on the way out of town. We were sure we’d get there too late. Lynn kept watch on the GPS’s estimated time of arrival. We were making good time.
We met Tony outside his house and we trekked out past the barn, winding up a path to the observatory, then through the snow and up a hill to a flattened out spot in the snow. We all had our binoculars and Tony and his wife Tara brought out their cameras. The crescent moon hung about 40 degrees up, a guidepost for finding the comet. Soon the sun sank below the horizon and we scanned the sky. Using an outstretched arm with our hand in a fist to measure 10 degrees, we estimated the height of the comet. It should have been 10 degrees below the moon, roughly halfway between the horizon and the moon.
Now’s it’s around 7:20, our feet are frozen bricks, cameras are seizing up and we’re not sure we can make it back to the car in the dark without taking a tumble. No comet yet, but we’re not giving up. Around 7:40 Tony’s phone rang – a fellow club member called, they had spotted it! A brief moment of disappointment that we didn’t find it first gave way to a frantic search. We all had our binocs carefully scanning, straight down from the moon and slightly to the right until – there it was! I was so amazed by the beauty of it, the bright nucleus and the hazy tail behind it. I couldn’t see it naked eye, (that whole visual contrast thing) but Lynn was able to.
The picture above was taken by Tony. After a few seconds of exposure the comet seems to pop in the picture! It looks like it was just blazing in the sky but it was really more of a fuzzy without binoculars. When we first spotted Panstarrs it was about 5 degrees above those trees on the left of the photo. It didn’t take long for it to set, maybe 20 minutes or so. We kept watching it until the photo ops were gone and our feet just couldn’t take it any longer. It was a beautiful sight, well worth the trek and cold!
We made it back to town in time to meet up with our club members at the pizza joint we frequent after our meetings. A hot cup of coffee warmed my hands and a bar-b-que pizza warmed my tummy. We exchanged stories of our adventure and they caught us up with club news and the upcoming Messier Marathon! Watch for that adventure in April.
Not a bad night!
Another successful observing session: great fun, great people, great viewing!
Now that we’ve had our fill of asteroid action for a while, let’s look forward to something a little calmer that’s heading our way this year. Two very bright comets are on the horizon, and one later this year could be the brightest in recorded history. I was fortunate enough to stand in the Arizona desert in 1986 and see Haley’s Comet, and I’m hoping that 2013 will be just as memorable.
Pan-STARRS (Comet C/2011 L4) will be its brightest on March 10 and will hang around until about the middle of April. After swinging around the sun, Pan-STARRS will pass through the constellations Pisces and Andromeda, and will be perfectly positioned for us to see here in the Northern hemisphere. It is expected to be visible to the naked eye and should have an impressive tail.
But the real excitement is building for ISON (Comet C/2012 S1). On Nov. 28, ISON will pass within 680,000 miles of the surface of the sun, much closer than Mercury. Because it is passing so close to the Sun, it is hoped that large quantities of ice and dust will boil off and give us an impressive show. ISON may even be clearly visible during the daylight hours during the days leading up to Christmas. Well, unless the Sun breaks it into pieces first.
Although there are always comets in the sky, most of them pass too far away from the sun to develop large, visible tails. The nuclei of a comet is primarily made up of ice, dust and small rocky particles, and when it gets close to the Sun, the Sun’s heat vaporizes the ice of the comet and blows the ice and dust away with the solar wind – which is why a comet’s tail always points away from the sun.
Fortunately, we haven’t heard anything about either comet passing too close to the Earth for comfort. I mean sure, Jupiter was hit back in 1994 by Comet Shoemaker-Levy, and again in 2009 by another comet that left a bruise about the size of the Pacific Ocean. But hey — we’ve got nothing to worry about, right? (Note: See earlier Bruce Willis entry).