A disk of gas and dust spins around the young star HV Tau C, nearly edge-on to us. The James Webb Space Telescope examined its spectrum and detected the glow of hot molecular hydrogen (H₂). This revealed a wide, bipolar wind blasting from the inner regions far beyond the disk. It's not a narrow jet but a diverging cone, like steam over a boiling pot, only heated to two thousand degrees.
The gas temperature appears in two layers. The warm component heats to about 600 kelvins, while the hot one reaches 2000 kelvins. The same pattern is seen around newborn stars. Outflow speeds, tens of kilometers per second, allow material to escape the disk within tens or hundreds of years. Each year, the wind carries away the mass of a small asteroid. Accretion, the infall of material onto the star, is estimated from hydrogen lines to be at the same level or slightly weaker, possibly because the disk is edge-on and some infalling gas is hidden.
So molecular winds don't vanish after a star's infancy. They keep working: removing angular momentum and clearing the surroundings, influencing where and how planets form. The disk around HV Tau C is a living organism that breathes hot hydrogen and carves itself from within.
Molecular hydrogen H₂ is the most abundant molecule in the universe, but it's notoriously hard to observe directly because it barely emits under normal conditions. JWST captures its heat in the infrared.
In Stanisław Lem's novel "Solaris," the planet's ocean also exchanges matter with space — though in a far more mysterious way than a hot hydrogen wind.