The Sun’s activity appears not only in the well-known 11-year Sunspot cycle, but also in short duration eruptions as flares and coronal mass ejections (CMEs). Such eruptive events, also known as space weather, can harmfully influence our Earth’s environment and technologies, such as GPS navigation, satellite communications and electric power grids. These events are accompanied with an enhanced radio emission of the Sun, especially in the frequency range (30-240 MHz) covered by LOFAR.
Hence, LOFAR is of great interest for solar physicists, since LOFAR with its spectroscopic and imaging capabilities is well suited for studying active processes in the Sun’s corona. This is the reason why the Key Science Project “Solar Physics and Space Weather with LOFAR” was founded. During LOFAR’s commissioning phase and the first cycles of regular observations, the solar KSP performed observations of the Sun, together with ASTRON.
On 30 January 2019, ASTRON, together with S[&]T started the design of a solar radio telescope to directly detect eruptions on the sun, at the request of the Ministry of Defence; the Royal Netherland Meteorological Institute (KNMI) is also involved. The project is called DISTURB (Disturbance detection by Intelligent Solar Radio Telescope or (Un)perturbed Radiofrequency Bands). “We finished the initial development phase on June 15th,’ says ASTRON senior scientist Michiel Brentjens. “Currently we are looking for funding, so that in the next three to five year we can build a fully functional prototype.” That prototype will then be able to directly detect eruptions on the Sun. Eventually the solar telescope might be scaled up to seven to twelve stations worldwide, providing global coverage.
An impression of what the solar radio telescope will look like. (Credit: ASTRON)
Brentjens points out that DISTURB is not so much an expansion of LOFAR as it is reusage of its technology. However, the development of this solar radio telescope will enable LOFAR 2.0 to study space weather more quickly and more accurately. DISTURB warns LOFAR that a solar eruption is taking place, so that LOFAR immediately can start measuring solar radio waves. Brentjens: “We no longer will have to stare at the Sun for weeks up to months without something happening; now we can immediately respond to a live warning from DISTURB; much more efficient!”