Calculate a shower’s activity levels
As a bonus, monitor brightness distribution, trail colours and meteor trains
Photographing a meteor shower with a digital camera can provide important information about trails and activity levels. This is done by calculating the zenithal hourly rate (ZHR), and the best way of determining that is visually.
Photographic ZHR is more complex because each camera setup is essentially unique. A calculation of camera specific photographic ZHR provides a relative indication of the change in shower activity over time. Photographs also give an idea of brightness distribution, trail colour and train activity. A meteor train is a column of ionised gas that can sometimes be seen glowing after a bright trail has finished. The formula covered in the six steps here is for visual ZHR and is suitable for use with visual results. It can also
The major annual meteor showers, their peak dates and values of the population index (r), used for ZHR calculation. A value of r lower than 2.5 favours brighter meteors, with higher values favouring fainter trails.
be applied to video results, again as a relative value unique to each setup.