Multi-wavelength observations of the flares in NOAA 8307 active region Original Research Article

We analyse in detail a series of four solar flares observed in NOAA 8307 active region on 18 and 19 August 1998 using ground-based Hα and space-based X-ray observations. All the four analysed flares had very similar structure. The observed changes in their morphology and physical properties can be attributed to the gradual changes of the macroscopic magnetic fields of the active region.