I agree with all of the above... A great image indeed! Definitely up the ISO to 1600, and shoot upwards of 10~15 exposures to counteract the noise.... 15x1min subs at 1600 will blow you away compared to 10x1min at 200!
Great first go at Omega Cent! I look forward to getting my first shot of Omega Cent hopefully in the next few weeks!
Alex.