i have 230 planets on scaned, so if i were remove those planet from the scans. can i scan for new planets with the same percentage as it was the first time ?i have the same equipment, Tachyon Sensor - Mark III, 446 scaning power.

if you scanned your first 230 with only 446 scan power, starting at your first one...
...then yes, if you were to purge them, your scan chance %'s would be the same as the first run...

current scan and current # planets in your list (regardless of ownership) affect your scan chance
(note: planets that are currently only visible to you because someone shared it with you do not affect your chance... unless you take the planet)

more planets = less chance of finding another (cloaked or not)
less planets = higher chance of finding another (cloaked or not)

more scan = higher chance of finding another planet (cloaked or not... though scan also helps you break through cloaks to keep the planet in your list)
lower scan = less chance of finding another planet (cloaked or not... though scan also helps you break through cloaks to keep the planet in your list)

ah okay thanks, now i just got to get 105 star chart purgers to get rid of the usless planets -.- any advice for that?

there's a mission available at lvl 115 that is repeatable an unlimited number of times... 750 total energy and 750 total exotic matter will give you 1 star chart purger

alternatively, you have a chance of getting star chart purgers for 1000 artifact points from your arti pulls... (if you drop below 1K, don't pull another arti... save up till you're above 1K again)

in addition to both of those methods... there's a third method (but it's really a waste of money for this particular item)... 8 GP = 1 purger

also does the scanning percentage count if i hacked a planet off someone?

yes, hacked planets are counted in the equation