The Comet C/2011 L4 (PanSTARRS) is scheduled to make an appearance low in the Dusk Western skies during the month of March. At first, the predictions for this comet were grand but now expectations have been greatly reduced downward. The Comet will make its closest approach to the Sun on 10 March 2013 where it will be very low in the bright Western twilight. The Comet will not easily be seen in the bright glow of Dusk's Twilight. The Comet when it's "at its best" for our area is predicted to be about +4 magnitude (which is as bright as some of the stars in the handle of the Little Dipper [Ursa Minor]). The comet is predicted to have about a 2 degree long tail (which is very short or about the size of the Pleiades Star Cluster [M45]). The Comet will not be easily seen with the unaided eye.
How to Observe It:
About 30 minutes after Sunset look for the Comet with binoculars. The Comet should be above and to the right of the Sunset point. It will be difficult viewing the comet in Dusk's Twilight. Small hand held binoculars may only show the brightest part of the Comet's head in the twilight. The tail is going to be much harder to see and much fainter than the head. To see the Comet's "V Shaped" tail well; you will need a pair of Giant Binoculars such as 25 X 100 or larger or telescope of 6" (150mm) aperture or more with a wide field. A typical wide field for a 6" (150mm) telescope; the magnification or power of the eyepiece would be around 25X and the view through it would be about 2 degrees.
The general observing window for the comet for our area is from 9 -19 March 2013. After the 19th of March the Moon will get brighter and wash out or ruin the views of the Comet. Also after the 19th the comet is expected to fade in brightness and size. Astronomical observing experience will certainly be useful in helping to locating this small comet.
Best Chance To See the Comet:
For the General Public the best chance to see this comet will be on 12th and 13th of March. Hand held binoculars will be necessary to find the Comet using the Crescent Moon as a guide. On 12th March the Comet will be just left of a very thin crescent Moon (about 30 minutes after Sunset, very low in the West). The next evening 13th of March, the Crescent Moon will be high above the Comet. If you have not found the Comet by 1 hour after Sunset; you will not see the comet. The reason why is the Comet has set by then. Binoculars mounted on a tripod or other support will help you steady the view and allow you to sweep (search) for the Comet.
This is not a favorable showing of Comet C/2011 L4 PanSTARRS for our area. There is a very narrow window of opportunity to see the comet at it's "brightest". This is not going to be a bright easy comet to find or see. Unaided eye views of the comet are going to be very difficult at best and disappointing. Observe the Comet too early after Sunset and the Comet will be washed out by the bright glow after Sunset. Wait too late and it will get dark and the Comet has already set. Binoculars will give the best chance of finding and seeing the comet.
If there are any changes with the Comet; more updates will be posted on this website.
Next Bright Comets (?):
Some of the internet websites have been talking about the possibility of 2 more bright comets this year. Let's take a look at the 2 comets:
C/2012 F6 (Lemmon):
This comet is currently visible in the Southern Hemisphere skies. This comet will not be visible in our area until May 2013 in the morning sky. By that time, the comet will have moved into the Northern Skies of our viewing area where it's expected to live up to its namesake. The comet is predicted fade in brightness and size; perhaps be at +6 magnitude (which is as dim as the faintest star you can see with your unaided eye.). If predictions hold true the comet will be barely visible to the unaided eye as a faint stain of light in the Northern Skies. There is not much hope for this comet to be a bright one.
C/2012 S1 (ISON):
This very faint comet is now beyond the reach of most amateur astronomers' telescopes. If things go as predicted; this comet could be the one. The comet is expected to slowly brighten up as it approaches towards the end of this year. If predictions come true then this comet could easily be seen by the unaided eye in the Pre-Dawn sky in December. One thing this comet has going for it unlike C/2011 L4 PanSTARRS; this comet will quickly move out of the Dawn Twilight and into the Pre-Dawn dark skies of December 2013. This comet will have a favorable showing for our area. By November 2013 we'll have a much better idea if this will become "The Great Comet of 2013". Of all the comets in the skies now, C/2012 S1 (ISON) has the best chance to be thee bright comet. Time will tell if the predictions and calculations are correct.
Gary T. Nowak
Vermont Astronomical Society