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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