LOFAR contributes to new solar eruption warning system

The design of a new solar radio telescope that works in conjunction with LOFAR to provide alerts on solar eruptions is now complete.

Appropriately named DISTURB, (Disturbance detection by Intelligent Solar radio Telescope of (Un)perturbed Radiofrequency Bands), its aim is to quickly alert other facilities to current and past solar radio interference on Earth. The design of DISTURB came from the Netherlands Institute for Radio Astronomy (ASTRON), S[&]T (Science [&] Technology Corporation) and KNMI (the Royal Netherlands Meteorological Institute).

Solar eruptions produce radio waves and sometimes also large amounts of UV and X-ray radiation that reach Earth, as well as large pockets of gas that typically arrive at Earth three days later. These gas clouds give us beautiful auroras but can also disturb or damage electrical systems and disrupt GPS navigation.

DISTURB detects the radio waves of solar eruptions in ‘real-time’; when the sun becomes over 4,000 times brighter than usual – and thus emits far more radio waves – DISTURB immediately alerts KNMI, the Dutch Ministry of Defence (both of which ordered the design of this solar radio telescope) and the LOFAR radio telescope, an SKA pathfinder. LOFAR can then immediately ‘turn its eye’ on the Sun as well and start more detailed observations.

DISTURB will track all radio waves with a wavelength between 10cm and 100m. For this, the solar radio telescope uses five different kinds of antennas, with which we can measure the amount of radio noise coming from the sun on over 600,000 different wavelengths. The antennas for the longest wavelengths are nearly identical to the ones LOFAR uses (LOFAR observes radio waves above 1.25m in wavelength); all others are either new antennas or re-used from parts of a design which LOFAR made for SKA during the design phase.

Although DISTURB will initially consist of a single antenna station, the DISTURB consortium aims to later have several DISTURB stations, distributed globally – just as LOFAR has. And also just as with LOFAR, DISTURB will send all its data to a central point. There is however one big difference: whereas LOFAR needs measurements to be synchronized up to a billionth of one second, for DISTURB this accuracy only needs to be around one tenth of a second, making it far easier to combine than LOFAR.

The next step is to find funding to turn the design into an actual prototype.

By Mischa Brendel (ASTRON)

Artist’s impression of a DISTURB antenna station.

Credit: ASTRON