DJ Cosmic Jellyfish Rocks The ABELL 2877 Cluster

QUOTE: “Astronomy compels the soul to look upward, and leads us from this world to another." - Plato

The picture rendered from the collected data using the Murchison Wide-field Array (MWA) in the FM 87.5MHz - c200 MHz range resembles a jellyfish and has been referred to not as Jamiroquai’s Cosmic Girl but rather the “Cosmic Jellyfish”. When observed from Earth it is over a third of the Moon's diameter but can only be seen with some low-frequency radio telescopes as most telescopes can't observe it at the low range or because of their location.

The image is reportedly quite bright around regular FM radio frequencies but drops off rapidly around 200 MHz which is very unusual and tricky to explain. The favoured explanation of the uniquely steep spectrum is that about 2 billion years ago, a handful of supermassive black holes from multiple galaxies spewed out powerful jets of plasma. This plasma then faded, went quiet, and lay dormant until recently the plasma started mixing again at the same time as very gentle shock waves passed through the system. Torrance Hodgson explains, “This has briefly reignited the plasma, lighting up the jellyfish and its tentacles for us to see…" as electrons at the edge of the cluster were gently accelerated and lit up dimly in the radio part of the electromagnetic spectrum.

The MWA is a precursor to the Square Kilometre Array (SKA) which will, along with many other telescopes being developed and built, add enormously to astronomers toolkit and pave the way for more amazing discoveries and images. The SKA will produce incredible amounts of data that will require new data processing and storage solutions that leverage diverse knowledge bases across the fields of maths, computing, astronomy, physics and perhaps even biology. Mr Hodgson’s doctoral supervisor, Professor Johnston-Hollitt, suggests that the SKA will enable the making of a high resolution, fast frame-rate movie of the evolving radio Universe from the first stars and galaxies through to the present day. What a blockbuster … and maybe DJ Cosmic Jellyfish can contribute to the soundtrack!

Its an exciting time to become an astronomer or cosmologist, far better than being an astrologer or cosmetologist!

QUOTE: “New directions in science are launched by new tools much more often than by new concepts. The effect of a concept led revolution is to explain old things in new ways. The effect of a tool driven revolution is to discover new things that have to be explained” [which then leads to technological and social spinoffs) - Freeman Dyson

As a final interesting aside experiments aboard NASA's first Spacelab Life Sciences (SLS-1) mission in 1991 investigated how space-raised jellyfish coped with life back down on Earth. NASA found the jellyfish had something akin to vertigo – pulsing and movement abnormally compared to their cousins born and raised in full Earth gravity. Unlike these space jellyfish DJ Cosmic Jellyfish has no such issues, happily bopping away in zero G!


Summary Links

Astronomers See A Space Jellyfish video

Astronomers See A Space Jellyfish

The Abstract of the paper:

Ultra-steep-spectrum Radio “Jellyfish” Uncovered in A2877”. The Astrophysical Journal, 2021 by

Torrance Hodgson, Iacopo Bartalucci, Melanie Johnston-Hollitt, Benjamin McKinley, Franco Vazza, Denis Wittor.



Space Time With Stuart Gary 29 March 2021 (c6 min 30sec in)

Professor Johnston-Hollitt discusses the SKA on The Science Show

Dark Matter Halo the band references the usual informative and humourous banter on “Daniel & Jorge Explain the Universe” of 2 March 2021 discussing globular clusters.


Music Of The Spheres: Music, Science and the Natural Order of the Universe”

Jamie James