Determination of the meteor limiting magnitude

Abstract

We present our method to calculate the meteor limiting magnitude. The limiting meteor magnitude defines the faintest magnitude at which all meteors are still detected by a given system. An accurate measurement of the limiting magnitude is important in order to calculate the meteoroid flux from a meteor shower or sporadic source. Since meteor brightness is linked to meteor mass, the limiting magnitude is needed to calculate the limiting mass of the meteor flux measurement. The mass distribution of meteoroids is thought to follow a power law, thus being slightly off in the limiting magnitude can have a significant effect on the measured flux. Sky conditions can change on fairly short timescales; therefore one must monitor the meteor limiting magnitude at regular intervals throughout the night, rather than just measuring it once. We use the stellar limiting magnitude as a proxy of the meteor limiting magnitude. Our method for determining the stellar limiting magnitude and how we transform it into the meteor limiting magnitude is presented. These methods are currently applied to NASA's wide-field meteor camera network to determine nightly fluxes, but are applicable to other camera networks.

A Reference Meteor Magnitude for Intercomparable Fluxes

“…where N(M ref ) is the number of meteors brighter than magnitude M ref passing through area  A within time interval T. If the meteors belong to a shower, they share a common velocity vector  v ; the unit vector v is aligned with the meteors' velocity vector. Note that  v is the meteor's motion through space, and not its apparent angular motion; the latter plays a role in determining the limiting magnitude (Molau et al 2016;Kingery & Blaauw 2017).…”