Far-infrared astronomy
Far-infrared astronomy is the branch of astronomy and astrophysics that deals with objects visible in far-infrared radiation (extending from 30 µm towards submillimeter wavelengths around 450 µm).
In the far-infrared, stars are not especially bright, but we can see emission from very cold matter (140 Kelvins or less) that is not seen at shorter wavelengths.
Huge, cold clouds of gas and dust in our own galaxy, as well as in nearby galaxies, glow in far-infrared light. This is due to thermal radiation of interstellar dust contained in molecular clouds.
In some of these clouds, new stars are just beginning to form. Far-infrared observations can detect these protostars long before they "turn on" visibly by sensing the heat they radiate as they contract.
The center of our galaxy also shines brightly in the far-infrared: These emissions are from dust in circumstellar shells around numerous old red giant stars. These stars heat up the dust and cause it to glow brightly in the infrared. The Bolocam Galactic Plane Survey mapped the galaxy for the first time in the far-infrared.
