1、thus ,we expect the square of the angular diameter,to vary on the average as the inverse square of the cluster's distance r from us.
2、if F(视亮度) are plotted against theta squared ,we should expect theoretically to see a straight-line relation
plotted against 什么意思(反比?)
3、there is scatter about the theortical line.
4、intrinsic variations(内因变化?)
5、because there must be intrinsic variations of the L and D of open clusters about some mean values
6、far-away clusters look intrinsically bigger than their measured apparent bighrnesses f would predict
7、such a special location for Eatrh has been anathema for astronomers since copernicus and this interpretation may therefore be reject
8、the ramaining possibility is then that far-away clusters have been dimmer by a general obscuration of starlight which incraese with increasing distance
远处的星团被星光遮掩早已变得昏暗,这种效果随距离增加而增加。
9、obscuring material is in the form of small solid specks, dust grains
遮掩物存在于小块物质、粉末中