The vernal or spring equinox occurs today at 01:02HST. Today there will be little difference between the length of the night when counted against the number of daylight hours. This is the first day of spring as marked by many cultures in the northern hemisphere.
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 over the Hawai’i, AT6RC and Canon 60D
This evening will see the Moon and Jupiter quite close, about 2° apart at sunset. Look for the bright pair high in the western sky as the sky grows dark. The Moon will be about 36% illuminated and Jupiter will be quite bright at -2.2 magnitude.
A very young moon over Waikoloa, this is only 26 hours after new, visible to the unaided eye as a sliver in the fading glow of sunsetNew Moon will occur today at 09:51HST.
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.
C/2011 L4 ( PanSTARRS ) positions in the sunset as it passes through perihelion, chart for March 10th, 2013
An awful photo of C/2011 Pan-STARRS, SBIG STi and 100mm lensBut 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?
Tomorrow morning, on March 10th, the Moon and Mercury will form a close pair. The Moon will be a very thin crescent, only 1.75% illuminated. Mercury will be only 2° below, shining at 2.7 magnitude. The pair will rise about 05:38HST, and will be 12° above the horizon at sunrise.
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.
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.
C/2011 L4 ( PanSTARRS ) positions in the sunset as it passes through perihelion, chart for March 10th, 2013
Today the planet Mercury passes through inferior conjunction, passing between the Sun and the Earth. In a week or so the planet will again be visible in the dawn sky, climbing higher each day. Maximum elongation will occur March 31st.
