Complex sentence: The gas is hotter and denser closer to the star, creating a pressure gradient that partially offsets gravity from the star allowing the gas to orbit at roughly 50 m/s below the Keplerian velocity at its distance.
Split into simpler sentences: The gas is hotter and denser closer to the star, creating a pressure gradient that partially offsets gravity from the star. The partial support allows the gas to orbit at roughly 50 m/s below the Keplerian velocity at its distance.