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?

Mercury Appears in the Dawn

Mercury will begin a morning apparition this week. The planet is currently about 10° above the rising Sun, climbing higher each morning. Look for a 2nd magnitude star-like object just above the glow of dawn. Mercury will reach a maximum elongation of 28° on March 31st.

Tomorrow morning, March 10th, the planet will be just 2° below a razor thin Moon. The Moon will be about 1.7% illuminated and will rise at 05:38HST, just 14° and about and hour ahead of the Sun.

200,000

Another large, arbitrary number… I have rolled the odometer on my 1995 Ford Explorer past 200,000 miles. It occurred when driving back from counting whales along the Akoni Pule highway north of Kawaihae.

Two Hundred Thousand Miles
The odometer of my Ford Explorer at 200,000 miles
When I bought this vehicle it was the first vehicle I had ever purchased new. I took delivery with eleven miles showing on the odometer. It seems so odd to consider 200,000 miles. I try to remember all of the wonderful memories of those two hundred thousand miles… Old mining roads in Arizona, dozens of star parties with the back packed with telescopes and gear, driving past sandstone arches in Utah, snow and ice covered highways, parked underneath a Saguaro cactus having lunch among desert wildflowers, the back heaped with wet scuba gear on a Hawaiian beach, a sunset atop Mauna Kea.

I remember worrying when I bought the vehicle, $23,000 was a lot of money to me back then, would I get to use the vehicle enough to make it worthwhile. Would I end up wrecking the vehicle in the first year? Would it be stolen or experience some horrible break down? Two hundred thousand miles later I can answer that question.

Keck Observatory Completes $4 Million Adaptive Optics Fund

W. M. Keck Observatory press release…

The W. M. Keck Observatory has successfully completed a $4 million campaign that will give astronomers the most detailed Adaptive Optics images of the cosmos ever created by mankind. Furthermore, the campaign was funded entirely by private philanthropy.

The Gordon and Betty Moore Foundation, the W. M. Keck Foundation and The Bob & Renee Parsons Foundation awarded three grants totaling $3.7 million to significantly upgrade the Keck II Laser Guide Star Adaptive Optics (LGS AO) system. The balance of the campaign came from individual gifts from Friends of the Keck Observatory.

Continue reading “Keck Observatory Completes $4 Million Adaptive Optics Fund”

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