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At 09:08 AM 7/5/96 +0200, you wrote:
>generally lunar are much less freqeunt than solar halos. To my mind that
>is mainly because the conditions for such event are rare, too. You need
>a bright (i.e. almost full) moon and uniform cirrus for a lunar halo
>to be seen at all. In addition, you can observe more often at daytime
>than during the night. On average, I am observing solar halos on
>approximately 70 days per year, but only about 10 days with lunar halos.
>
>So long, I've never seen colored lunar halos, since they are
>*really* rare. In the German network such events are observed only a few
>times per year. I guess it has to do with the sensitivety of our eyes: If
>the light source is too faint, we don't see any colors but only
>black/white images. So many lunar halos might in fact be colored, but we
>cannot recognize it in most cases. Remember great comet Hyakutake (if it
was
>visible from your latitude ;-) - it showed wonderful colors on
>photographs, but they did not appear to the naked eye.
>Sirko
At the time I saw the colored lunar halo, it was full moon, so I guess
the criteria of a bright light source clearly fit the bill. What was
amazing about the halo then was that its color intensity caused a lot
of people to notice it. The normal white halo is normally noticed only
by those really interested, like us. This instance of a colored lunar
halo was the first time I saw such an event. Really breathtaking, plus
it lasted quite a long while (about 2 hours)!
On Comet Hyakutake, yep, we were able to see it quite well during the
month
of March and first week of April. Was really glad to be in an equatorial
position so we could see the comet well when it started in Libra and went
north. Of course, the only disadvantage was watching it spend time near
Polaris, since at 15 deg. North, Polaris and the comet were dimmed by the
horizon haze. Still the comet was really fantastic, and in a dark site,
the
ephemeral blue color of the long tail was fascinating. Believe we also
noticed that the coma was blue-green in color when the comet was moving in
close to earth, while the inner coma was white. The only color we did not
see were the reported orange coloration near the head.
The letdown was seeing it in the southern sky when it developed a dust
tail.
The skies had already deteriorated over our area as the monsoon season had
started. Too bad! We should have seen it too!
Jun
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< Jun Lao, Editor, the Appulse >
< The Philippine Astronomical Society >
< Bringing the Heavens Down to the Filipino >
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