Comet C/2011 L4 PanSTARRS

Well past perihelion comet C/2011 L4 continues to put on an impressive show. Amateur sky-watchers have been enjoying the impressive anti-tail reaching out a few degrees from the coma. True, you may need a telescope or at least good binoculars to see the comet. It may be dimming, but still worth the effort to observe.

Comet C/2011 L4 PanSTARRS
Comet C/2011 L4 PanSTARRS, 10x4min with TV-76 and Canon 60D @ISO2000

Comet C/2011 L4 Pan-STARRS

The weather finally broke, leaving a clear western sky and a chance to photograph the comet. I set up and managed just a few shots before the comet set into the top of a tree across the street.

At least I was able to get on-sky. Much more than can be said about our ‘scopes on the mountain. Observing was cancelled earlier this afternoon, there is too much ice on the domes to operate safely. At least the ice was pretty, and photogenic.

Comet C/2011 L4 Pan-STARRS
Comet C/2011 L4 Pan-STARRS over the Hawai’i, AT6RC and Canon 60D

Comet C/2011 L4 Pan-STARRS at Perihelion

Today Comet C/2011 L4 (Pan-STARRS) will pass through perihelion, its closest approach to the Sun. Take a good look now, given the 110,000 year orbital period, the comet will not be back anytime soon.

The comet should be visible as a 1st magnitude object 13° above the horizon at sunset and directly above the glow of the setting Sun. It will climb higher each evening after passing through perihelion. It will begin to fade as well, most likely dimming below 4th magnitude by the end of March.

Comet 2011 L4 Perihelion
C/2011 L4 ( PanSTARRS ) positions in the sunset as it passes through perihelion, chart for March 10th, 2013

Comet C/2011 L4 Pan-STARRS

Now for a truly awful comet image.

C/2011 L4 PanSTARRS
An awful photo of C/2011 Pan-STARRS, SBIG STi and 100mm lens
But it is all I managed to get this evening. A to-do list that is much to long and vehicle trouble caused me to reconsider plans to observe at the VIS. Thus I planned to observe the comet from the driveway. This works well in some respects, using the mounting points in the driveway I can have the ‘scope reasonably well polar aligned in the daytime. This would make finding the comet far easier, I could offset from the Sun and have the ‘scope aimed at the correct coordinates before it was dark.

It had been wonderfully clear all afternoon. It was just as the sky darkened that trouble appeared, a band of high clouds sweeping in from the west. Noooo!

The comet appeared in the STi guide camera right on schedule, my coordinates less than half a degree off! Not bad with a manual telescope mount offsetting from the Sun. The clouds swept over the comet a few minutes later, just as the tail was beginning to appear in the darkening sky.

I did grab a few images from the guide camera and snap a few frames with the DSLR. The monochrome CCD on the guider managed slightly better shots despite a fairly bright sky. I managed a few more frames as an opening appeared a few minutes after that. It is still an awful image. The only reason I could tell it was the comet is that it remained centered as the clouds swept through the image. Take my word for it, the barely there spot at the center of the photo is the comet.

At least my vehicle is fixed, a new alternator in place. Try again tomorrow?

Comet C/2011 L4 Pan-STARRS Closest to Earth

Today Comet C/2011 L4 (Pan-STARRS) will make its closest approach to Earth. Not that that is saying too much, close approach will be 1.09 AU or about 101,300,000 miles, just over the average distance from the Earth to the Sun. In contrast Comet C/2012 S1 (ISON) will approach us to closer than half that distance, about 0.42 AU or 39,000,000 miles from Earth on December 26th, 2013.

The comet should be visible as a 2nd magnitude object 7° above the horizon and a little south of the Sun at sunset. It will climb higher each evening, passing through perihelion, close approach to the Sun on March 10th.

Comet 2011 L4 Perihelion
C/2011 L4 ( PanSTARRS ) positions in the sunset as it passes through perihelion, chart for March 10th, 2013

Comet C/2011 L4 Pan-STARRS

Like so many other amateur astronomers, I am eagerly awaiting the appearance of Comet C/2011 L4 Pan-STARRS.

The comet was discovered in June of 2011, by the Pan-STARRS survey telescope atop Haleakala, Maui. The comet will pass closest to earth on March 5th, at a distance of 1.09 au. Perihelion, the comet’s closest approach to the Sun, occurs early on March 10th UT.

Comet 2011 L4 Perihelion
C/2011 L4 (PanSTARRS) positions in the sunset as it passes through perihelion, chart for march 10th
For northern hemisphere observers the comet is still quite low, just rising out of the Sun’s glare. Over the next week it will rise above the sunset, and will be 12° above the horizon at sunset on Saturday, March 9th.

Initial predictions were quite optimistic with this comet, indicating a possible -1 magnitude for the comet. Reality seems to be somewhat more restrained, with a peak somewhere between magnitude one and two being more likely. Reports indicate that the comet has brightened to about 2nd magnitude, bright enough to be easily seen without optical aid.

Even more convenient, the comet will be well placed for observation this coming weekend. With new moon occurring on March 11th, this will be the prime weekend for a telescope outing. Amateur astronomers everywhere are already planing for this weekend. Our local club is no exception, expect a good crowd of telescopes to be at the Mauna Kea VIS this weekend. Myself? I will probably setup at the Substation site, just across the road from the VIS. The site offers a much better western horizon, which is blocked from the VIS by a line of pu’u, old cinder cones.

I will be taking photo gear, looking to get a decent photo of the comet. Stay tuned to Darker View to see the results if I meet with any success.

The latest orbital elements from the MPC

Another interesting opportunity will come on March 12th, when a slim crescent Moon will join the comet in the sky. A 1.4 day old moon, about 2% illuminated will be about 4° north (to the right) of the comet.