Sunday, March 18, 2012

Night and Day

The wonderful thing about having a small home based observatory is that there is virtually no set-up or preparation involved in observing.  Simply head outside, roll off the roof and wake the telescope mount from hibernation.  After a long day of work it is simply a 30 foot walk out the backdoor and I am relaxing under the night sky.

Earlier this week I was at a meeting with University of Arizona Astronomer Carl Hergenrother, who maintains an excellent blog called The Transient Sky which deals with comets, asteroids and meteors.  I highly recommend a visit to his site.  Carl reminded me that Comet C/2009 P1 Garradd was still fairly bright in the evening sky in the northeast.  I have been following this comet since late August 2011, when I first sketched it at magnitude 8.2 and have since made about a half-dozen sketches of it.  I remarked to Carl that I was amazed at how long this comet had remained fairly bright.  He indicated that the sustained brightness is a result of a rather large comet that did not approach the Sun very closely.  He remarked that had it come closer, it may have become a "Great Comet."

I last visited this comet in early February (see this post) and decided to have another look.  The comet is currently heading for a rendezvous with the Big Dipper asterism in Ursa Major and is well placed for observation much of the night. Below is a diagram of the comets orbit (courtesy JPL).

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Below is my sketch of Comet C/2009 P1 Garradd completed at 0420 UT on 3/15/2012 (9:20 PM MST 3/14/12).   At the time of my sketch, the comet was 1.301 AU from Earth and 1.91 AU from the Sun.

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As you can see, I was not disappointed in the mighty comet.  It is moving along at a stately pace of approximately 3.27 arcseconds per min and is currently sporting two diffuse tails.  The tail to the east appears much broader and more diffuse than the tail to the west.  I made this observation using my recently acquired TEC 8 inch f/20 Maksutov, with a 35mm Panoptic eyepiece yielding a magnification of 116x.  Current estimates place the comet at approximately magnitude 7.4.  I will be in Portal, AZ this coming weekend under magnitude 7+ skies and am very excited to have a look at Comet Garradd under truly dark skies.  Look for a follow up sketch next week.

Of course, the Lost Pleiad Observatory is a round the clock operation and until I invent a way to see the deep sky in the daytime (in visible light), I still observe our nearest star, the Sun every chance I get.  Below is a sketch I made of the Sun using my dedicated Hydrogen Alpha telescope on March 17th.  Happy St. Patrick's Day!

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