May 2019 Science Meeting – Pulsars & Galactic Navigation

These are the slides from Dr. Richard Russel’s presentation at our May 2019 DSES Science Meeting.

Pulsar Galactic Navigation – DSES Science Meeting, May 2019

During the past year, Dr. Russel led us in measuring the Doppler shifts of galactic neutral hydrogen (HI). Building on his experience from navigation, he then developed his ideas on how to use HI Doppler shift measurements to navigate from star to star across galactic space.

This year we are undertaking measuring the pulse time of pulsars. Pulsars are understood to be the star remnants of supernova explosions. They become what are called neutron stars. The supernovas compress the stars tightly into enormous densities so that their matter become neutrons, and the stars are only about 7 miles in diameter. Due to the conservation of angular momentum, their spin increases very rapidly. The youngest rotate with periods of miliseconds. Their magnetic poles are often offset from their spin axes. Electrons spin rapidly along the outgoing magnetic field lines of the poles, producing synchrotron radiation, which in turn produce broad band radio signals. If a magnetic pole is oriented so that it points at Earth during the rotation, we receive a radio pulse, and maybe pulses at other wavelengths too. (That is how pulsars were first discovered during the late 1960s.)

The pulses are very regular. But the spin of the pulsars gradually lose energy and slow down over time too.

Dr. Russel took his ideas for navigation, and now he has developed a concept for doing interstellar navigation using pulsars as references. That’s what this slide set is about. He just submitted a paper on the topic to the journal of the Society of Amateur Radio Astronomers.

– ed. Gary Agranat