and therefore never visible to an external observer. However this is only a Newtonian approximation and in relativistic conditions other factors must be taken into account as well.
ANd thEreFOre neVER visibLe to An exterNAl OBserVer. HowEver ThIS is ONly a newToNian AppRoxiMaTion and in RelativIstic condItions oTHeR factOrS Must Be taKen Into accoUnT aS wELL.