At 250 million light-years, Arp 220 has a luminosity of more than “a trillion suns.”
Shining like a bright beacon amid a sea of galaxies, Arp 220 lights up the night sky in this view from NASA’s James Webb Space Telescope.
Actually two merging spiral galaxies, Arp 220 shines most brightly in infrared light, making it an ideal telescope target.
It is an ultraluminous infrared galaxy (ULIRG) with a luminosity of more than a trillion suns.
By comparison, our Milky Way galaxy has a much more modest luminosity of about ten billion suns, according to NASA.
Located 250 million light-years away in the constellation of Serpens, the Serpent, Arp 220 is object number 220 in Halton Arp’s Atlas of Odd Galaxies.
It is the closest ULIRG and the brightest of the three closest galactic mergers to Earth.
The collision of the two spiral galaxies began about 700 million years ago. It caused a huge burst of star formation.
About 200 huge star clusters reside in a dusty, compact region about 5,000 light-years across (about 5% of the diameter of the Milky Way).
The amount of gas in this tiny region is equal to all the gas in the entire Milky Way.
Previous radio telescope observations revealed about 100 supernova remnants in an area less than 500 light-years.
NASA’s Hubble Space Telescope discovered the nuclei of parent galaxies separated by 1,200 light-years.
Each of the cores has a rotating ring of star formation that emits the dazzling infrared light so evident in this view by James Webb.
This dazzling light creates diffraction spikes, the starburst feature that dominates this image.