A Method for Comprehensively Determining the Vector Magnetic Field of A Solar Active Region

In this article the scanning photographic data of the strong magnetic field of a solar active region are used to calculate the total magnetic field,and longitudinal magnetic field,and then to derive the value of the transverse field,of which the direction is determined in the light of the morphology of the penumbral filaments,thereby calculating the vector magnetic field of the active region.The advantages of this method are that only a simple observing equipment is needed and that the vector magnetogram can easily be obtained by means of the spectral data reduced wrth.a computer.But the shortcoming of this method is that the vector magnetic field obtained is limited with in the sunspot regions.However,it is known that most of the trigger points of solar flares appear in the sunspot regions of which the structures are complex;and therefore the method is of great significance and worth while being applied and popularized.As an example,the vector magnetic field of Hale No.17906 sunspot group is calculated ih detail.