[Prev][Next][Index][Thread]
Re: (meteorobs) Fireball mags...
In a message dated 97-09-04 23:25:45 EDT, you write:
<<
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 saw that -19 fireball, I figured I could have just as easily called it
anything from a -17 to a -21 and still feel satisfied...I took the
middle...-19. I based this magnitude upon the -15 that Bob and I witnessed
earlier ...the one that produced a sonic boom and all for us....this fireball
was a lot brighter than the -15 by a long shot. With a -15 fireball...I've
never heard anyone stating that they had to shield their eyes because it was
too bright for them to look at. Since I did with the -19...I figured it had
to be significantly brighter than the -15. The -15 was arrived at from the
very pronounced shadows on the ground and the estimate of a full moon at -12.
I guess I could have submitted a range of magnitudes to FIDAC...that is -17
to -21 and let them guess for themselves what magnitude to catalog it
as...but since I was the one that saw it, I thought it would be best that I
made the judgement call and make the final estimate to settle on....thus it
became a -19.
George Zay
Follow-Ups: