Friday, 22 May 2015

Solar Eclipse Through LOFAR's Radio Eyes

Whilst KAIRA and an assortment of LOFAR's international stations were observing the ionosphere for effects of the solar eclipse on 20th March 2015, the main Dutch LOFAR array was imaging it in radio across the majority of the frequency range available with these antennas.  Images were produced in near real time and released on social media as press releases later that day.  Today, an ASTRON "Image of the Day" showed the latest movie of these images, also reproduced below.

Michiel Brentjens, who led the effort to run the experiment and produced the images describes the day at ASTRON in the Netherlands:

"The images shown here were observed in the high band from 115 to 170 MHz, while low band observations were happening using the very same stations. Every frame consists of 5.5 seconds of data, recorded at a cadence of once per 5 minutes.

Soon after the first images appeared on twitter, an ad-hoc team of colleagues showed up in the control room to volunteer their services. In the end we had Roy van der Werp (media contacts and Astron overview page about the solar eclipse), Jan David Mol and Wouter Klijn (social media and notification of various web sites), Tammo Jan Dijkema (creating and updating movies of the eclipse up to the latest image, see movie), Ronald Halfwerk (Astron branding, and creating of eclipse movies combined with introductions to LOFAR and Astron), and Michiel Brentjens (observations and imaging)."

A superb effort from all involved!

Friday, 8 May 2015

Midnight Sun on Svalbard

As summer is on its way, here on Svalbard we have had the midnight sun for several weeks already. Last "night" turned out to be optimal to try a photomontage with the sun slowly approaching the northern horizon and being only hidden by the mountains.
The picture below is based on images taken between 22:00 yesterday evening and 03:15 today (local time), from the third floor exterior stairs of the Sjøskrenten student housing, in Longyearbyen.

Picture: M. Grandin.