June 9, 2010

Look For Comet McNaught C/2009 R1 In The Early Morning

Comet McNaught C/2009 R1 will become brighter than first thought and will be visible to the naked eye over the next few weeks.

Australian astronomer Robert McNaught discovered the comet last September using the 0.5-meter Uppsala Schmidt telescope and a CCD camera. 

Enough observations were made of the comet to allow Brian Marsden of the Smithsonian Astrophysical Observatory in Cambridge, Mass., to calculate its orbit.

Comet McNaught is expected to pass closest to the sun at 37 million miles on July 2. 

The comet is visible now for people with dark skies away from urban and suburban lightning.  It may be an easy skywatching target for most people by mid-June.

Comets brighten as they get closer to the sun because solar radiation boils icy particles and dust off the comet's nucleus. 

As the comet approaches the sun, amateur and professional astronomers around the globe have been watching with interest as it slowly increased in brightness.

The comet was estimated at magnitude +12 when April began.  That is about 250 times dimmer than the faintest star that one might see with an unaided eye.  However, the comet started brightening more rapidly in the days and weeks that followed and it is now bright enough to be seen with the naked eye in a dark, clear sky.

Alexandre Amorium of Florianopolis, Brazil told Space.com that he saw the comet on June 6 by using 10x50 binoculars and estimated the magnitude as +5.5.  That is about as bright as the faintest star in the bowl of the little dipper.

The comet is expected to continue to brighten as it gets closer to the sun.

The best time for a person to try and catch a glimpse of the comet is about two hours before sunrise.  The comet is currently moving through the constellation of Perseus, which will be low in the northeast part of the sky at an early hour.

The comet will appear as a dim and diffuse, circular path of light. 

John Bortle, a well-known comet observer, said McNaught's appearance resembles an "apple on a stick."

"From the few rough magnitude estimates I have seen posted, it would appear that the comet is perhaps a magnitude brighter than had been anticipated, but whether this trend will continue is, as usual, anybody's guess," Bortle told Space.com.

Comets are unpredictable, but astronomers believe the comet will reach a magnitude of +2 by the end of June.

Image Courtesy Royal Astronomical Society of New Zealand


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