Jocelyn Bell and the antenna

3. A Pulsing Signal

Members of the Cavendish radio astronomy group built the new telescope. Among them was Jocelyn Bell, who had joined Professor Hewish as a research student at the start of construction. When the telescope started operating in July 1967, Jocelyn Bell was responsible for operating it and analysing the data.

The telescope output data on four 3-track pen recorders, producing around 30 metres of chart paper each day. These charts were analysed visually by Jocelyn Bell, who quickly learned to recognise scintillating sources.

Two months into her observations Bell became aware of a bit of 'scruff' on the records. This new signal didn't look like it was due to a scintillating source or any sort of man-made interference. Checking back through her records Bell found the scruff had occurred before but always came from the same patch of sky.

This strange new signal deserved closer attention, so at the end of October Jocelyn Bell started making faster chart recordings of the correct area of sky. For weeks she found nothing, then finally at the end of November the source appeared on a fast recording. The 'scruff' was a series of pulses, equally spaced and always 1.3 seconds apart.

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