cheers guys thanks for your reply. the star is Xi1 Centauri, Catalogue number: HIP63724. Hi Louie, im already using GradientXterminator. the gradient is explained here:
http://www.iceinspace.com.au/forum/s...ad.php?t=19205
due to electricity cables.

next time, i need to image at certain time then let it pass the electricity cable then image again.