The Sardinia Radio Telescope (SRT), one of Europe’s most advanced radio observatories, is undergoing a major technical upgrade before resuming its study of fast radio bursts and other deep-space phenomena. The work is expected to keep the facility offline until at least September.
Sardinia Radio Telescope Prepares for New Observations
Reaching the Sardinia Radio Telescope requires a winding journey through the rugged mountains north of Cagliari, the Italian island’s main port city. The isolated landscape contrasts sharply with the sophisticated 64-metre radio telescope that has produced notable scientific results during its first decade of operation.
Surrounded by extensive sheep and cattle pastures, the observatory sits on a plateau roughly 700 metres above the Mediterranean Sea. The location was selected partly because the surrounding terrain offers protection from wind and relatively low levels of radio interference.
The fully steerable telescope cost approximately €60 million to build. Along with supporting radio astronomy research, it forms part of the European Space Agency’s deep-space communications network.
Technical Upgrade to Expand Telescope Capabilities
The SRT is currently offline while engineers complete a significant technical upgrade. Once operational, the facility will continue conducting general astronomical observations while supporting communications with spacecraft travelling through deep space.
The telescope routinely observes radio frequencies ranging from 300 megahertz to 116 gigahertz. For comparison, the lower end is broadly associated with conventional television broadcasting frequencies, while the upper range overlaps with radar technologies used in modern vehicles.
More than 1,000 individual aluminum panels form the telescope’s large parabolic surface. Each panel is supported by electromechanical actuators that maintain the precise alignment needed to collect faint radio signals from distant regions of the universe.
Telescope Detected Record-Low Fast Radio Burst Frequency
The Sardinia Radio Telescope’s best-known achievement is its detection of the lowest-frequency fast radio burst recorded at the time.
Fast radio bursts, commonly known as FRBs, are powerful flashes of radio energy lasting only a few milliseconds. They originate at cosmological distances and can release enormous amounts of energy despite their extremely short duration.
The SRT detected FRB 180916 at a frequency of 328 megahertz. The signal originated in a star-forming region inside a massive spiral galaxy nearly 500 million light-years from Earth, in the direction of the northern constellation Cassiopeia.
The discovery helped astronomers broaden their understanding of the frequency ranges at which these mysterious signals can be observed.
One-Time Bursts and Repeating Signals
Researchers generally distinguish between fast radio bursts that appear only once and those that repeat. Some repeating FRBs, including FRB 180916, have displayed activity patterns with measurable periodicity.
Scientists have proposed that one-time bursts could result from catastrophic cosmic events, such as the merger of two neutron stars. Such an explosion would not be expected to produce additional signals from the same source.
“Repeaters cannot be caused by a one-time explosion,” Maura Pilia, a radio astronomer at the Cagliari Astronomical Observatory in Sardinia, said by email.
For repeating bursts, one of the leading explanations involves magnetars, Pilia said.
Magnetars Remain a Leading Explanation for Repeating FRBs
Magnetars are neutron stars with exceptionally powerful magnetic fields. Their intense activity is believed to be driven by the loss and reconfiguration of vast amounts of magnetic energy.
The Milky Way contains numerous known magnetars. However, all fast radio bursts detected so far appear to have originated beyond our galaxy.
When the upgraded Sardinia Radio Telescope returns to service, its broad observing range and highly precise surface will allow astronomers to continue investigating FRBs and their possible origins. Its future observations could help determine whether magnetars account for repeating bursts and clarify what produces the universe’s more elusive one-time signals.
Sophie MacKenzie is a contributor to CA News Ottawa, covering news, politics, business, technology, sport, entertainment, and lifestyle. She focuses on clear, accurate reporting and useful information that helps readers stay informed about current affairs and developments that shape their communities. Her work highlights relevant stories, emerging trends, and important issues, presenting them in a balanced, accessible, and reader-friendly manner.
