(meteorobs) Need moon magnitude help please

[Chris Peterson]

Hi Tom-

For conventional Moon phase (0% new, 100% full), you can use this:

mag = -3.33 ln(phase) + 2.79

to give the zenithal magnitude of the Moon. You might want to correct that 
for zenith angle, just as you would for a meteor, although it usually isn't 
necessary when using the Moon as a brightness reference for fireballs.

At the time of your event, the Moon's phase was 72%, so I'd put its 
brightness at mag -11.5. At an altitude of 50°, I wouldn't worry about any 
corrections to that. Your meteor was low enough, however, to be somewhat 
attenuated. If you are able to compare it with the Moon, you should probably 
increase its estimated brightness slightly to compensate for atmospheric 
extinction.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "Thomas Ashcraft" <ashcraft at heliotown.com>
To: "Global Meteor Observing Forum" <meteorobs at meteorobs.org>
Sent: Friday, October 09, 2009 10:31 AM
Subject: (meteorobs) Need moon magnitude help please


>I captured a super-sized fireball last night over New Mexico and need to
> know the Moon magnitude for 0804 UT, Oct 9, 2009.
>
> I am creating my report at this moment but can't find Moon magnitude
> calculations on the internet.
>
> Thank you in advance for your assistance!
>
> Thomas Ashcraft