May 30, 2020

02.11.09:The Low-Down on LOFAR.

European radio astronomers at the Netherlands Institute for Radio Astronomy (ASTRON) have recently opened a potentially new window on the universe with an exotic new instrument. Dubbed LOFAR, or the Low Frequency Array, this unique instrument will examine the sky at extremely low radio frequencies, with a low band of 30 to 78 MHz and a complimenting high band of 120 to 168 MHz. In contrast, the radio dish at the Arecibo Observatory in Puerto Rico operates in a range of 400-5000 MHz. We’re talking very low frequencies, in a range not well understood. Three arrays currently centered on Exloo in the Netherlands saw first “radio light” earlier this year, examining the powerful radio source Cygnus A, a suspected black hole candidate. As computer power increases, scientists hope to add arrays across Europe from Britain to the Ukraine to increase the resolution of the array. The low gain antenna masts are simple and cheap to construct, and are basic omni-directional dipole antennas utilizing a synthetic aperture. LOFAR will map events at low radio frequencies, from ionization in the Earth’s atmosphere caused by gamma-ray bursts to corneal mass ejections on the Sun to re-ionization of neutral hydrogen in the primordial universe. And that’s not to mention any surreptitious discoveries that always seem to crop up when a new portion of the electromagnetic spectrum gets analyzed… perhaps some ultra-advanced race communicates via low frequency black hole resonances? I seem to remember a plot in Arthur C. Clarke’s Imperial Earth that involved intelligent aliens and low frequency waves… watch for LOFAR “antenna farms” cropping up along the European country-side soon!