First pulsar detected - November 28, 1967

On this day in 1967, astrophysicist Jocelyn Bell Burnell became the first person to detect a radio pulsar.

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Episode Transcript

Speaker 1 (00:00):
This Day in History Class is a production of I
Heart Radio Greetings, I'm Eves and welcome to This Day
in History Class, a show that believes no day in
history is a slow day. Today is November. The day

(00:25):
was November. Nineteen sixty seven, Astell physicist Jocelyn Bill Burnell
became the first person to detect a radio pulsar. A
pulsar is a celestial source of pulse stating electromagnetic radiation
that is thought to be a rapidly rotating neutron star.
Pulsars amit pulses of radiation like radio waves, at short,

(00:47):
relatively constant intervals. In nineteen sixty seven, Jocelyn Bell was
pursuing her doctorate at the University of Cambridge, where her
advisor was radio astronomer Anthony Hewish. That year, Huish and
his graduate students completed a radio telescope that was designed
to observe the scintillation of stars, particularly quasars. A quasar

(01:10):
is a region at the center of a galaxy that
omits an exceptionally large amount of energy. The first quasars
were discovered by the early nineteen sixties. Bill helped build
the telescope at the Millard Radio Astronomy Observatory. Once the
telescope went into operation in July of nineteen sixty seven,
Bill began operating it and analyzing the data by hand.

(01:33):
One day, she noticed a strange signal at a wavelength
of three point seven meters. The signal continued to appear
over the next several months. On November, she captured a
recording of the signal that gave more detail. Bill called
the reading a quote bit of scruff in the data.
It showed that the signal corresponded to a burst of

(01:54):
radio energy that came in regular intervals of about one
point three seconds. The re was sinked with sidereal time
rather than Earth time, and it consistently came from the
same part of the sky. So she set about determining
the source of the signal. It couldn't be coming from
any natural sources like stars, galaxies, or solar wind, and

(02:15):
it did not come from any human or human made
sources like radar reflected off the Moon, other radio astronomers,
television signals orbiting satellites, or buildings near the telescope. After
ruling out all those sources, she and Huish called the
signal l g M one because they couldn't rule out
little green men a k a. Aliens, But soon Bill

(02:38):
found another signal, this one pulsing at one point to
second intervals. This signal was coming from a different part
of the sky. That meant that the signal was likely
not sent by extraterrestrial beings. Later that year, Bill noticed
a couple more of these unusual signals. In January nineteen
sixty eight, Bell Hwish in colleagues submitted paper describing their

(03:01):
discovery to the journal Nature, and the paper, Observation of
a Rapidly Pulsating Radio Source was published on February. The
paper noted that they had recorded unusual signals from pulsating
radio sources and positive that the radiation may be associated
with oscillations of white dwarf or neutron stars. But even

(03:24):
though they had announced the discovery, they still didn't know
the source of the signal. That didn't stop other scientists
from trying to discover more of these pulsating sources and
where they were coming from. By the end of nineteen
sixty eight, more had been discovered, and it had been
suggested that neutron stars were a source. Hewish first used

(03:45):
the word pulsar in an interview with the Daily Telegraph.
In nineteen sixty, Bell and Hwish changed the name of
the signal from l g M to CP or Cambridge Pulsar,
and the first radio pulsar they detected was dubbed CP.
Nineteen eighteen, he was received the nineteen seventy four Nobel
Prize in Physics for his role in the discovery of pulsars,

(04:07):
a controversial decision because Bill's contributions were not recognized. Since
their discovery, pulsars have been used to study extreme states
of matter and search for gravitational waves. I'm Eve Jeffcote,
and hopefully you know a little more about history today
than you did yesterday. Send your best history memes to

(04:28):
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