Comet C/2006 VZ13 (LINEAR) & Aurora

Date: 11 July 2007 U.T.
Time: 5:50 U.T.
Instrument: 20x80 Binoculars
Seeing: Steady (for binoculars)
NELM: 6.5
Temperature: +55 F (+13 C)


The above sketch shows the basic appearance of Comet C/2006 VZ13 LINEAR as seen with hand-held 20x80 binoculars. Only a few of the many visible field stars appear in this sketch. South is up. West is to the left. The comet is the large, round, nebulous object with a brighter middle. The galaxy, NGC 6015 was visible in the 20x80 binoculars as a much smaller and fainter nebulous object to the west of the comet. The comet was easily visible with 8x42 binoculars as well as with the 20x80s.

The comet was in the constellation Draco. Its rough location at the time of this observation was RA 15hr 57min, Dec. +62 degrees 28min. I estimated the comet's coma to be about 0.2 degrees in diameter. The comet is currently well placed in the evening sky for observers at mid-northern latitudes.

An aurora was visible a few degrees above my northern horizon. The aurora was somewhat brighter (with a small amount of structure visible) around 5:20 U.T. than it was at the time of the comet observation (5:50 U.T.). The aurora never extended very much above my northern horizon and seemed to have little or no effect on the limiting magnitude higher in the sky.

Aurora Borealis

Date: 15 December 2006 U.T.
Time: 2:00 - 4:15 U.T.
Transparency: Mostly Clear to Mostly Cloudy
Latitude: 45.5 North
Location: Northwestern U.S.

Shortly before 2:00 U.T. I stepped out the south door to check sky conditions. (The sky had been cloudy earlier.) I was greeted by a mostly clear sky and a strong glow in the east. A look out the north door verified my suspicion: An aurora was in progress.

A large, bright, pale green auroral glow extended from within Orion in the east-southeast through Auriga, Cassiopeia, etc. all the way to Cygnus in the northwest (basically following the Milky Way) and all points northward. The display consisted of an amorphous glow with a few, small, pulsating patches -- mostly in the northeast.

At roughly 15 minute intervals I checked on the auroral activity. Throughout my auroral watch the large glow described above remained visible. This glow had the appearance of a huge, broad dome. Its high point, in the direction of magnetic north, was within a few degrees of the zenith.

Around 3:15 U.T. a pulsating arc would occasionally appear and disappear in a matter of seconds, passing above Polaris.

By 3:45 U.T. the thin clouds were beginning to grow thicker everywhere. A short, bright, rayed-arc was visible near the horizon in the direction of magnetic north (a few degrees east of true north). This arc, in addition to the huge glow mentioned earlier, remained visible until the clouds became nearly opaque at 4:15 U.T.