The magnetism of galaxies

Open Night on 13 July 2019
“The magnetism of galaxies”


Members of the public are welcome to an Open Night at the SAAO in Cape Town on 13 July 2019, starting at 20h00. Dr. Samuel Legodi (South African Radio Astronmy Observatory (SARAO)) will present a talk titled The magnetism of galaxies. This will be followed by a tour of the site and (weather permitting) star gazing.

Summary of the talk

The interaction of electrons and magnetic fields produce some of the most spectacular displays of physics that can be observed with the naked eye such as the aurora above the Earth’s North and South poles. The same magnetic field guides certain migratory animals along to greener pastures amid unfavourable seasonal conditions. Still the same field shields organic life on Earth from harmful extra-terrestrial radiation. The same physical phenomenon, that is magnetism, results in the sunspot cycle observed on the solar surface.

Magnetism is also responsible for spectacular behaviour in other cosmological objects, such as pulsars, rapidly rotating and beaming magnetically generated signals at the Earth that a young Jocelyn Bell and contemporaries initially thought to be the work of little green men on a far away planet. Magnetic fields are also known to influence the formation of new stars as they influence the collapse of star-forming regions, exerting pressure to counteract gravity in stellar nurseries. On larger scales, these magnetic fields have been observed to mysteriously form complex patterns in galaxies and clusters of galaxies.

Dr. Legodi will give an overview of magnetism as we have observed on Earth and in the cosmos, along with some of the techniques used for such endeavours.


The Open Night will take place at the SAAO in Cape Town. The SAAO is located off Liesbeeck Parkway, next to the River Club.


Gates open at 19h30 and parking is available on site.

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