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(meteorobs) Fireball mags...
Hi guys,
Marco wrote:
>Probably my brightest meteor was a daylight fireball in 1986 that must have
been -15 or so... A -10 appeared a year later. But in honesty, I guess that
anything brighter than -10 is difficult to estimate. I think that an
estimate like -19 should
be mentioned as near -20.
I find that -19 vs. the -20 comment interesting. Personally, the brightest
I've ever seen was -10, and I've seen only two of them since I started
serious meteor observing back in 1968. Mind you, I missed most of the
1980's...
But, how do you guys estimate really bright fireballs? I agree with Marco
that a -19 should probably be called a -20. For myself, I go by the
brightest stars and planets, then the moon, and have impressions of
magnitudes in the middle.
When I was observing with Pierre Martin for the Perseids, I asked him before
the start of the max night, how he would call the magnitudes for several
mercury campground lights in the distance (<behind> where we were facing!).
Good exercise for both of us...
I have seen a lot of fireballs under -10, but I think I'd call a -10, not a
-9 if something was in that range. In other words, the judging gets more
'binned'. Something from -9 to -11, I'd probably call a -10. Likewise, for
some of the other mags for the bright stuff...
Comments? Any guidelines??? Nighttime guidelines vs. daytime guidelines,
when sounds (if any) kick in, how much shadow cast, effect of colour on
guidelines, etc....
- Cathy
Great White North