Sitting here with me ATPL notes on STAR/DELTA generators, trying to make sense of it again, just as well it didn't come up in the exam the other day!
From what I have it appears that a STAR has four outputs, the centre one being the one that is earther to the airframe (your Aux it would appear). Being three phase (hence the six diodes) there should be three outputs, one for each phase. Two should be at Line voltage and one a phase voltage, line voltage = 1.73 phase voltage.
I may have got it all wrong, but you may have another 2 outputs somewhere. The advantage of the star system for an airliner is that there are to voltages available, which may result in fewer transformers being needed.