The epoch when the very first stars appeared is a key period of cosmic history. These stars began the manufacture of the chemical elements (those heavier than hydrogen and helium) and their light began the reionisation of the neutral cosmic gas. These stars thus mark the dawn of the universe as we know it today and the start of the so-called Epoch of Reionisation.
The National Science Foundation has approved funding to expand the Hydrogen Epoch of Reionisation Array (HERA) in South Africa. Upgrading the number of antennas from 19 to 240 by the year 2018 will enable HERA to study more clearly the impact of cosmic dawn, the moment a few hundred million years after the Big Bang when the first stars and galaxies blazed awake.