I get it since the block is a ghost to anything the only thing it isn't a ghost to is trying to place something within it's space, sort of like a door or an area block.god mode -> go to the EXACT center of the sector-> build a station in cubic form-> one-several blocks should refuse to place, showing you the star's "origin" block.
[DOUBLEPOST=1438212972,1438212818][/DOUBLEPOST]I wonder if you can hit is with anything? Since it shouldn't collide with anything once you have it's location shooting things at it to test what it is and isn't able to be shot by should be an easy task.