本星系群

介绍了本星系群中最大的旋涡星系M31（仙女星系）的基本观测性质。

Observational properties of the largest Local Group spiral M31 ( Andromeda galaxy ) are presented .

仙女星系（M31，NGC224）是本星系群中最大的旋涡星系，而且离银河系并不遥远，无疑为我们提供了有利的观测条件。

Andromeda galaxy ( M31 , NGC224 ) is the biggest spiral in the Local Group . Since it is not far from Galaxy , it provides us a unique candidate that the galaxy structure and morphology can be observed carefully .

现在，我们来介绍一下明确属于本星系群的几个较小的成员星系。

For the moment let us describe the minor members that we are sure belong to the Local Group .

这些数据可以计算出时空弯曲的程度，从而也可得出我们邻居，一个含有50个星系以上被称为本星系群的质量大小，我们银河系和仙女座都包含在这个星系群中。

That allowed them to calculate the deformation of spacetime , and thus the mass , of our stellar neighborhood , aka the Local Group - a group of more than 50 galaxies , in which the Milky Way and Andromeda dominate .