Astronomers might soon be able detect the first stars in our universe. Scientists have created a new detection technique that could help with this.
This method uses a radio line of neutral hydrogen or a line 21 cm in length. This radiation is actually the radiation that was emitted during the Dark Ages when the young Universe was filled with hydrogen atoms.
These signals are extremely weak, hundreds of thousands times weaker than the typical radio signals found in our galaxy. Complex data analysis is necessary to identify such signals. Scientists will be measuring the difference in hydrogen cloud emission and signal behind them. They hope to see stars like “shadows in fog”.
It is very difficult to find the first stars. According to the Big Bang theory the Universe was transparent to electromagnetic radiation in the Dark Ages. However, the first stars were also surrounded by clouds made of neutral hydrogen. These absorb light extremely well and make it difficult to observe or detect the light from such objects.
Scientists are looking for stars that formed around 400,000 years after Big Bang. However, some studies have suggested that stars could have formed as early as the proton age, which is only 30-50 000 years after Big Bang.
Scientists will use the Square Kilometer Array radio telescope (SKA), currently under construction, for research. This radio interferometer will be the largest in the universe. Its antennas are located in Australia and New Zealand, with South Africa as its base. Its sensitivity is 50 times greater than similar telescopes. This should allow it to be used by astronomers to create new ideas.