Meteor Shower Radiant Calculator

HR = ZHR * sin(altitude) * (1 / (lm_factor))

Zenithal Hourly Rate (ZHR)

Radiant Altitude (degrees)

Limiting Magnitude

Formula

Visible Rate = ZHR * sin(altitude) / limiting_magnitude_factor

What is ZHR?

Zenithal Hourly Rate is the theoretical maximum number of meteors visible per hour under perfect conditions with the radiant at zenith.

Why do I see fewer meteors than the ZHR?

The radiant is rarely at zenith, light pollution reduces limiting magnitude, and sky conditions vary.

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