From ESA press releases, January 31 and February 5, 2015:
New maps from ESA’s Planck satellite uncover the ‘polarized’ light from the early Universe across the entire sky, revealing that the first stars formed much later than previously thought.
Between 2009 and 2013, Planck surveyed the sky to study this ancient light in unprecedented detail. Tiny differences in the background’s temperature trace regions of slightly different density in the early cosmos, representing the seeds of all future structure, the stars and galaxies of today.
Scientists from the Planck collaboration have recently published the results from the analysis of these data in a large number of scientific papers over the past two years, confirming the standard cosmological picture of our Universe with ever greater accuracy.
However, despite earlier reports of a possible detection of gravitational waves in the polarization of the CMB, a joint analysis of data from ESA’s Planck satellite and the ground-based BICEP2 and Keck Array experiments has found no conclusive evidence of primordial gravitational waves.