Come on breh. Cell was bullshyttin. Everywhere on the internet has debated this shyt. Everywhere with intelligence says Cell was bullshytting. The only way dude was taking out the Solar System was causing the Sun to supernova. If Cell could have taken out the Solar System that means Gohan had to have sent back equal power to compete with his attack, right? Their attacks collided and only left a small crater from the impact. That is not Solar System destroying power. Cell has to blow the Sun up to blow up the Solar System. He can't do it any other way. I can't believe people in 2012 still overhype DBZ characters. Go read Saint Seiya or b*stard or Jo Jos or something else with actual strong people. Hell specific people in Bleach and Naruto could beat Goku.
Who know's if cell was bluffing but he did just a massive zenkai and inherited goku's strengths and powers. It basically comes down to who u believe. Again the DBZ world does not function the same as the world we know so blowing up the solar system might be different in dbz than marvel.
You also have to remember gohan was holding back on his attack from cell because he was afraid he was going to destroy the planet as stated here.
Dragon Ball Online Manga · SPECTRUM NEXUS