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Re: (meteorobs) Aurora images online

    Paul wrote:

> Perhaps our more northern folks would like to
> chime in on visual appearance of aurorae (if it is not too off-topic).
> Since you are likely to see the one while you are looking for the other,
> however, maybe it isn't OT??

    I certainly wouldn't consider it so. I make mention of aurora in almost
every meteor report I submit. Just scanning back over this year's reports on
the Quadrantids:

> A huge single curl of mild aurora split the sky from north to south
horizons, receded for a while, then came up again in the neighbourhood of
the radiant, eventually forcing me to turn to the east and south. Midway
through the evening a ripple of cirrus cloud passed through, slightly
reducing our limiting magnitude.

...and Lyrids:

> All that said, my "dark sky" offered a few challenges other than
moonlight.
A band of aurora persisted in the northeast, blocked in places by the "dark
nebulae" of some heavier cloud. The aurora threatened at times to take over
the sky, gently rippling with potential energy which on this occasion at
least, never quite rolled up its sleeves and went to work. The brighter
portions of the aurora cut the limiting magnitude in half or more, and its
unpredictable subtle movement was quite distracting to the task of watching
for the unpredictable sudden movement of meteors.

    ...and delta Aquarids:

> Mild aurora and forest fire smoke conspired to keep the limiting magnitude
to a modest 5.0 or so, so I knew counts wouldn't be particularly high, but
it's easy to be patient when one has the beautiful night sky to keep one
company.

    I didn't even file my Perseids report this August because that session
was spoiled by aurora and lightning! (no relation)

    We get them frequently enough up here in central Alberta that a "no
aurora" night is worth noting. Living in the city makes me a poor judge, but
I have heard people say we experience some sort of aurora upwards of 100
nights a year, and I believe it.

    Most of it is relatively nondescript and a bloody nuisance to any sort
of serious observing, especially if transparency is an issue. But every once
in a while we get one of those 8 or 9 out of 10 all-sky blow-out aurorae,
and it is only the unfortunately single-minded observer who seems to object.
The best is the so-called coronal aurora, where the magnetic field lines are
directly overhead and the lucky observer can look right up the dancing grass
skirts of Madam Aurora! At those times one can occasionally see bursts of
super-saturated colours, primarily in the greens and violets but during
intense outbursts, almost more than I have language to describe.

    One particular morning of interest I remember was the Perseids of 2000.
It cleared very late, and under the clouds were ripples and flashes of
aurora that made it difficult at first to realize the clouds had receded. I
got about one hour at a "dark" site, and I saw about every different
recognized type of aurora -- rays, arcs, rayed arcs, flaming, glowing,
pulsating, patch, coronal, homogeneous, you name it. Beyond the aurora, or
around the same altitude, would shoot the occasional (bight) Perseid. In the
northeast rose Saturn and Jupiter, my first sighting of the giants since
they had shifted places while in conjunction with the Sun; now they were
grouped with the Hyades and Pleiades in the temporary asterism I instantly
dubbed the Millennium Diamond. Algol was in eclipse. I have never seen a
more dynamic (night) sky in two decades of observing.

    But my meteor count went straight out the window that night too. That
time at least, it was worth it.

    regards, Bruce

    PS: For more images, the excellent website www.spaceweather.com has a
gallery on pretty much an ongoing basis. Click on the hyperlink "auroras"
which is usually right on the front page. The site keeps track of solar
activity and forecasts geomagnetic activity (thus the name), particularly of
potentially major aurorae that some of you located in more southerly climes
might experience. There was one in October following that Class X28 solar
flare that was seen in the deep southern US.


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