| Description: | The radio sky is an extremely violent environment which is constantly changing. Periodic compact objects, such as pulsars and RRATs, and cataclysmic single events like the famous "Lorimer Burst" can produce flashes of radio emission which vary on timescales as short as milliseconds. One of the aims of the LOFAR Radio Sky Monitor (RSM), a programme of the Transients Key Science Project, is to find these sources. In LOFAR cycle zero the RSM is focussing on a survey of the fields that pass overhead at the array, the "zenith strip". This animation shows a snapshot of a single HBA beam from the survey which has been 'time-sliced' to look for rapid variability. Each frame of the animation corresponds to a 10-second slice of the 11-minute snapshot. Near to the centre of the field (highlighted in the green box) is radio pulsar B0329+54; a nearby field source of comparable mean flux density is highlighted in the red box. The light curve in the lower panel shows the flux from each source measured from the 10-second images. Although some apparent variability is seen in the field source, the pulsar is clearly flaring a varying much more dramatically, trebling on timescales of less than a minute. This is the first clear detection of rapid source variability in LOFAR images: a systematic search for rapid variability in all images comes next. |
