The phrase "gas envelope" refers to a surrounding layer of gas that surrounds something, like a planet or a spacecraft. It acts like a protective cover, providing insulation or trapping certain gases. Full definition
And we just got our solids, liquids, and gases envelope in the mail. (themeasuredmom.com)
Eventually, Stars Aa and Ab will lose much of their current mass, from intensified stellar winds that eventually puff out their outer gas envelopes of hydrogen and helium (and lesser amounts of higher elements such as carbon and oxygen) into interstellar space as planetary nebulae. (solstation.com)
Eventually, the star will lose much of its current mass, from an intensified stellar wind that eventually puffs out its outer gas envelopes of hydrogen and helium (and lesser amounts of higher elements such as carbon and oxygen) into interstellar space as a planetary nebula. (solstation.com)