当黑子接近日面西边缘时，向中心一方的半影没有消失的趋势。

When the spot approaches the west limb, the penumbra toward the disk-center has no tendency to disappear.

youdao

当黑子接近日面西边缘时，向中心一方的半影没有消失的趋势。

When the spot approaches the west limb, the penumbra toward the disk-center has no tendency to disappear.

youdao