South African astronomy is big news at the moment, with the exciting and ongoing development of the Square Kilometer Array (SKA) and the precursor telescope, MeerKAT.
But there is another array that people don’t hear about too often. You will be forgiven if you have never heard of the Hydrogen Epoch of Reionisation Array (HERA) telescope, which is also located in the South African Karoo Astronomy Reserve. That should change now that it’s bagged a R128 million investment from the US National Science Foundation, which will be used to expand on its current capabilities and begin imaging the very earliest formations of stars to light the sky.
Only a few kilometres away from from the MeerKAT radio telescope, HERA has 19, 14-metre radio dishes designed to study low frequency wavelengths from 50-250MHz. In July it was been granted the status of a Square Kilometre Array (SKA) precursor telescope, and scientists will use it to inform the design of the SKA-low antennae and analytics over the next few years.
With the extra cash injection, the 19 dishes will be expanded to 37, with the ultimate goal of having as many as 220 dishes in two years’ time.
But what exactly does HERA do? Well, it has only one job, and that is to characterise the epoch of reionisation, of course. That’s the name given to the period of time before the stars were formed.
“HERA is designed to detect radio waves in the low-frequency range of 100–200 MHz, which allows it to detect fluctuations in the emissions from neutral hydrogen gas that was found throughout the universe before stars, galaxies and black holes formed,” SKA explains in its overview.
In short it will give us a 3D map of the universe.
“The Universe was formed in a Hot Big Bang of particles and radiation 14 billion years ago, but soon cooled down and was dark for hundreds of millions of years, before any stars formed. Nobody yet knows when these stars formed. Today’s announcement increases the chances that signs of the first stars and galaxies ever to be created will soon be detected – in South Africa’s Northern Cape,” explains the SKA South Africa chief scientist, Dr Fernando Camilo.
When the project is completed. the HERA array will be the most sensitive of its kind in the world. And it’s in your backyard.