Seeing in a New Light (and Searching for Extraterrestrials) with LOFAR
One of the coolest things about being an astronomer is being the first one to look at brand new data of some distant object in our universe. It is even more exciting when we, as a community, are breaking into new or barely-explored regions of the electromagnetic spectrum. LOFAR (the pan-European Low Frequency Array) is one of several projects doing just that.
At the Royal Astronomical Society’s National Astronomy
Meeting in Glasgow, LOFAR released new images and observing plans for
the telescope that is currently under construction. With 44 stations, each with dozens of antennas, spread across Europe, the observatory will have unprecedented spatial resolution for meter-wave astronomy.
With nearly half of the stations built, they present a really great image of a radio source called 3C61.1. This shows the jets of relativistic electrons screaming away from the supermassive black hole of a distant galaxy. Low frequency observations show less energetic, or older, populations of electrons, thus showing us emission that traditional centimeter-wave radio telescopes may not detect.
In addition to radio jets, cosmic rays, intergalactic hydrogen, and whatever new natural phenomena are out there, LOFAR has signed on to help with the Search for Extraterrestrial Intelligence, or SETI. After all, we don’t know what frequencies our Galactic neighbors might be using for communication, so we may as well check as many as we can!
The first step is a feasibility test. That is, can researchers remove all the man-made radio interference well enough for SETI? I can tell you from experience, there is a LOT of interference at these frequencies (I’m looking at you, digital TV.)
Although it has been 50 years since the first SETI project by Frank Drake in Green Bank, West Virginia, we have yet to find a signal. We have, however, only been exploring a small part of our galaxy and in limited frequency ranges. Any expansion of our capabilities is helpful to the search, as long as they don’t find anything before I teach my “Life Beyond Earth” class this summer. I’d hate to have to rewrite the syllabus on short notice!
VIDEO: Will the real ET be little green men or little green bacteria? SETI Institute Senior Astronomer Seth Shostak theorizes what our first alien encounter might be like.
Image: New image of 3C61.1 from LOFAR on the right, compared to previous low-frequency surveys (center) and 21-cm observations with the Very Large Array (left). (Reinout van Weeren (University of Leiden)/ASTRO)