It appears as a spiral galaxy, which may be barred.

它看起来是一个旋涡星系，但可能是一个棒旋星系。

Barred spiral galaxy NGC 4731 lies some 65 million light-years away.

棒旋星系ngc 4731约在6500光年以外。

The mystery arises when one considers how a spiral galaxy rotates.

当人们考虑旋涡星系是如何转动的时候难题就来了。

On the right, surrounded by blue spiral arms, is spiral galaxy M81.

右边被蓝色旋臂环绕的是旋涡星系m 81。

Note that the shape of the normal-looking spiral galaxy has changed.

请注意，形状正常前瞻性的螺旋星系发生了变化。