Institution(s): 1. The Planck Collaboration
Planck scanned the entire sky every six months at nine frequency bands from 28 to 857 GHz with enough sensitivity to detect over a thousand extragalactic radio sources. It thus provides measurements of the mm and sub-mm spectra of these sources in a regular cadence, even at wavelengths hard to observe from the ground. Polarization measurements (or upper limits) are provided for brighter sources at 28-353 GHz. Finally, Planck is calibrated to <1% accuracy in most of its frequency bands.
I will first introduce the valuable data set Planck provides on extragalactic sources, in particular the Second Planck Catalogue of Compact Sources (PCCS2), then more briefly describe some of the scientific conclusions drawn from the Planck measurments.