Wednesday, March 6, 2013

Updates: Viewing Comet PanSTARRS

by Alan MacRobert

Looking west in bright twilight. Don't expect the comet to be this obvious!
Bring binoculars to pick the comet out of the twilight low in the west. Don't expect it to look as obvious as this! For a finer-scale chart starting earlier, see the bottom of this page.
(Diagram Source: Sky and Telescope Magazine)

Long awaited, Comet PanSTARRS (C/2011 L4) now looks likely to break 2nd magnitude at its brightest around March 10th, when it will still be low in the western evening twilight for Northern Hemisphere observers. (Here's a graph of its altitude above the horizon by latitude on that date.)

So far, Southern Hemisphere skywatchers report that its condensed appearance and high surface brightness have been helping its visibility in twilight. Our turn in the north should begin very soon now!

We covered the comet in the February and March issues of Sky & Telescope. Here's the latest:

March 6: Moving north! The latitudes where Comet PanSTARRS can be seen low after sunset are moving north day by day. The Southern Hemisphere has had a good look, as the reports and pictures of the last few weeks testify, and it's still in view there; here's a March 4th pic from Trevor Sellman in Australia. And here's some video from Australia March 5th, naked-eye equivalent and then through a 10-inch Dobsonian scope.

But the zone of good visibility is heading north now through the tropics. For instance, last night (March 5th) came this report from "Preston in San Miguel de Allende" in central Mexico, latitude 21° N. He was at an elevation of 6,000 feet, certainly a big advantage. "I observed PanSTARRS last night at about 6:50 p.m. for 10 minutes before it descended into the smoke/haze only to be totally lost. It was easily naked-eye visible, and the tail could be made out without binoculars."

Right now the comet is moving north by 3° per day and has almost stopped its apparent motion toward the Sun (at a solar elongation of 16°). Its zone of visibility should reach the latitudes of the southern U.S. very soon now depending on your sky conditions.

For instance, at the latitude of Los Angeles (34° N) tonight, the comet will be only 3° above the horizon a mere 20 minutes after sunset (a little to the left of due west). They're going to try from Griffith Observatory there starting tonight anyway.

More - Link >>>

Source: Sky and Telescope Magazine.

Special Thanks: Eric G. Canali, Former Floor Manager of Pittsburgh's original Buhl Planetarium and Institute of Popular Science and Founder of the South Hills Backyard Astronomers amateur astronomy club.

Related Blog Posts --

Comet Pan-STARRS Brightens for March Apparition (2013 March 5):

 Link >>>

Possible Naked-eye Comet in March  (2013 Feb. 7):

Link >>>



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