Discovered by Hubble, the target galaxy has nine rings, like Saturn!
The Bulleye galaxy shows nine marked rings. © NASA, ESA, IMAD PASHA (Yale), Pieter Van Dokkum (Yale)
Although fortuitous, it is a great discovery that we owe to Hubble and a researcher from the University of Yale: a galaxy which has nine rings! It was previously known as the little poetic name of LEDA 1313424, but its complex structure had not been spotted so far. She has now taken the nickname of Bulleye Galaxy, the “target galaxy”.
“It's serendipitysaid Imad Pasha, doctoral student at the University of Yale (Connecticut). I consulted an imaging study on the ground, and when I saw a galaxy with several clear rings, I was immediately attracted. I had to stop to investigate, and it was the team that then nicknamed it the target galaxy. ”
If we compare it to our Milky Way, it is twice as large with around 250,000 light years in diameter, making it a cosmic juggernaut-our galaxy is “only” 100,000 light years. The target galaxy is in the direction of the constellation of fish, at a distance from the land of 567 million light years, therefore beyond our super-continent Laniakea.
Comparison of the size of the Milky Way and the Target Galaxy. © NASA, ESA, Ralf Crawford (STSCI)
Rings full of gas, stars and planets
It is in fact a spiral galaxy which was crossed about 50 million years ago by another, dwarf it, just in its center-we see the latter, bluish, on the left of the 'Image at the start of the article. This is also the reason for its name of the target galaxy, because the arrow is still present. It is his spiral arms which, because of this interaction, adopted this ringed structure filled with gas, stars and planets.
Thus, we observe this galaxy at a very precise moment in its history, but with in addition the ideal angle of view which creates the illusion of very concentric rings.
A ninth ring to govern them all
It can be noted that only eight rings are visible to the naked eye, but a ninth was detected by the Keck telescope.
Illustration showing the nine rings. © NASA, ESA, Ralf Crawford (STSCI)
Last very interesting point: this transformation into rings of the spiral galactic arms had been predicted by mathematical models on this crossing scenario by a dwarf galaxy, but never observed in this small temporal window possible. It is therefore a happy confirmation of the theory that Hubble permitted.
“It is extremely rewarding to confirm this long -standing prediction with the target galaxy”said Pieter Van Dokkum, co -author of the study.
