The James Webb Space Telescope (JWST) has redefined humanity's capacity to study the cosmos. Its unprecedented sensitivity in ...

Studying the line spectra produced by hot gases and absorbed by cooler gases allows us to identify the elements in stars. When a gas is very hot, it doesn’t emit all wavelengths of light.

High brightness, narrow bandwidth pulses: They collapsed the frequency combs to a single, ultra-bright "tooth"—i.e., a single spectral line with ... Spontaneous Emission in an X-Ray Free ...