Cygnus A

Date of the discovery: 1939

Short Description: Cygnus A was, along with Cassiopeia A the first radio sources detected. Cygnus A is a radio galaxy with two radio lobes. These lobes are thought to be originating from relativistic jets coming from an active galaxy nucleus (AGN). These jets have speeds close to the speed of light and show effects that are described in general relativity (therefore relativistic jet). The discoverer Grote Reber had interests in amateur radio and amateur astronomy and combined them to radio astronomy. He was the only radio astronomer for a decade, conducting the first sky survey in radio frequencies. He build on the work by Karl Jansky.

Amateur Astronomer(s): Grote Reber

SIMBAD page:

Telescopes involved: 160 MHz reciever

Image of the radio telecope (credit: Grote Reber, source:
Other pages:


Credit for the header image: C. Carilli NROA (

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