system
Given the following post, respond as if you're commenting on Reddit:
human
Why do scientists say TrES-4, the largest discovered exoplanet, should 'theoretically not exist'?

I understand it is partially because the planet is so big of course, but I would like a more in depth answer, I couldn't find any.
gpt
It's much larger than jupiter, but much less massive. This is somewhat paradoxical. Jupiter itself is a gas giant, with a good portion of the planet being clouds of gas. For an even larger planet to be even less dense doesn't make much sense to scientists, as all the gravity of the planet should pull in the gasses to form a more dense ball. Since the gravitational constant doesn't vary throughout the universe, a planet of a specific mass really only has a certain range of sizes that make sense, and this planet falls outside that range.