2018 schedule

Sun 11:30-11:45
Mercure Conservatory

The variation of sky brightness with latitude and sidereal time in the absence of Moon or clouds

James Irish

Member, Astronomical Society of Victoria

The "New world atlas of artificial sky brightness" (Falchi et al., 2016) assumes that night sky brightness at dark-sky sites when the Moon is not visible and there are no clouds is 22.0 magnitudes per square arc second for the V spectral band. However, this depends on the solar cycle and, especially for sites in the southern hemisphere, latitude and sidereal time. Results will be presented, together with a model, for sky brightness in eastern Australia. The model is applicable to any site between latitudes 20 and 43 degrees South, and can be generalized to sites affected by light pollution.