Sky brightness is an essential topic in the field of astronomy,especially for optical astronomical observations that need very clear and dark sky conditions.Thi
We observed an Hα surge that occurred in NOAA Active Region 12401 on 2015 August 17, and we discuss its trigger mechanism, and kinematic and thermal properties
From the Reuven Ramaty High Energy Solar Spectroscopic Imager(RHESSI) catalog we select events which have approximately the same GOES class(high C- low M or 500