Photoevaporation Valley · The Radius Gap
unseel.com · XUV wind · super-Earths · sub-Neptunes
Valley 1.8 R⊕
L_x/L_bol saturated ~10⁻³
Stage
Young X-ray star
XUV / escaping H
Sub-Neptune (keeps gas)
Stripped rocky core
Unseel.com · Photoevaporation Valley: How Stellar X-rays Carve the Radius Gap