C/2011 L4 (PanSTARRS)
First Observation (click on image below to enlarge)
Second observation (click on image below to enlarge):
Third observation (click on photo to enlarge):
Nikon D40: f/5.6, 200mm lens at ISO 800 for 4 seconds (cropped)
EAST ^ NORTH >
FIRST OBSERVATION: This comet was anticipated to be -1 magnitude at perihelion, which generated a lot of interest! It also "warmed up" well in the Southern hemisphere. That said, the tail length pre-perihelion wasn't very long, and it didn't seem to lengthen after perihelion (like some comets did for Southern hemisphere observers in recent years). It seems to have managed approximately magnitude zero, but is riding so low in the Western horizon after sunset to make it extremely difficult to see naked-eye.
My first observation was on Tuesday March 12, from the dog run area of Broemmelsiek Park, along with Steve Boerner. The very thick clouds prior to sunset were just beginning to thin out a little. It seemed crazy to even go out in the cold (upper 30's) temperatures with so many clouds, but I knew that I'd kick myself if it cleared off and others saw this comet and I didn't. After the sun had set, the clouds continued to thin as the sky began to darken. The wind was somewhat cruel, at 15-20mpg, which made it hard to face West.
I first acquired the comet in my 25x100 binoculars (tripod-mounted) at 7:45pm CDT. It was 3-4 moon widths left (South) of the thin crescent moon, which was only slightly more than 28 hours old at the time I spied the comet (I observed the young moon first at 7:19pm CDT = 28hrs 27mins old.). I was able to view it shortly thereafter in my 10x50 binoculars, in which the moon fit into the same field of view (FOV) just barely. The view in my 10x50's was nice, but the view in the 25x100's was jaw-dropping.
When viewing with the 10x50's, I could set my view up so that a distant tree would point to the comet. This enabled me to intermittently seeing the comet naked-eye. Under the seeing conditions though, I could not 'hold' it for more than a few seconds. Naked-eye sightings happened at 7:55pm and a few times more, ending around 8:05pm. I sized the comet by comparing to the moon. To me, the entire comet length was 1/3rd of the moon's diameter, so about 1/6th of a degree (10 arc minutes).
On Wednesday, March 13, 2013, the weather had been clear most of the day, and the excitement was building. I arrived at the planned meet-up, the DOE Mound at Weldon Springs, just before 7pm and grabbed my camera, tripod, and 25x100's and started climbing. Twenty-nine had come here to see the comet, and the conditions were close to perfect. Thank goodness the wind was low tonight!
David Lloyd called out the first sighting, and I was among the last! My first view was at 7:39pm CDT and my last view was at 8:16pm. Tonight I only had extremely fleeting naked-eye views, and tonight it was coma only, no tail naked-eye. Best views were from 8pm to 8:14pm on this night, from this mound top. Best tail length was at 8:13pm.
I spent some time trying to take some photos, but I had not had time to practice that day (a busy day at work) and so I struck out on one setup item. So, I put the 25x100's back on the tripod and continued visual observations.
The comet's tail was noticeably shorter on the Southern (left) side than on the longer and sharper right (Northern) side. The coma's p-nucleus was very bright and elongated. At it's best (8:13pm) I estimated the tail length to be 1/2 the moon's diameter, so that equates to 1/4 of a degree, or 15 arc minutes ( or expressed as 15').
Quite a bit cloudier this evening, but like the 12th, most clouds thinned out after sunset. I decided to spend this evening only taking pictures, and did so. The photo at left was taken at 8:08PM CDT March 13 from Broemmelsiek Park. Down is West, and right is North. The photos do a better job of showing color, and during bright twilight the comet appeared yellow-white, later yellow-orange, and as it neared the horizon it became reddish-orange.
The tail length, during the few times that I observed it visually, seemed to be just under 1/4 degrees. Slightly shorter than the night before. However, there was a lot of clouds in the sky, so no doubt the sky conditions were sub-optimal for seeing the tail thru the atmosphere.
I was at the park "solo" that evening, and was very glad to have my full concentration on the camera, as I really wanted to get a decent photo! I ended up taking 22 photos that showed the comet's progress, from early appearance in a bright sky to it becoming reddish-orange and diving into the tree line.
The camera was mounted on a mini-tripod, affixed to my car-top luggage carrier. I set the 10-second delay timer each time, to avoid shaking the camera (I have no remote shutter release). It was ghostly to see it show up so well on the camera's LCD, when I could not see it at all naked-eye.
I'm looking forward to many more observations on this comet.
Did a bino's only observation from my neighbor's driveway on March 14. No drawings. Showed the comet to my wife, my neighbor Brian, and his two sons thru the tripod mounted 25x100's and the hand-held 10x50's.
The days have been rainy, cloudy, and the rivers have flooded the past month or so. It has not been good for comet observation. The weekends have all been cloudy.
Finally from a dark site! Observed PANStarrs at 12:20AM on May 12 from Danville MO with the 25x100 binos, hand-held, near Gamma Cephei. Slight condensation, tail was averted vision but strongest "straight" and fanned out to the East diffusely. I did not notice an ion tail. I decided not to draw it (no mount for the binos). I am surprised that this comet tail is holding up so well visually still. Made me really wish that I had brought my telescope that night.