This marvelous image captures two interacting ‘peculiar’ galaxies that lurk more than 300 million light-years from Earth, in the constellation of Andromeda.
The distorted appearance of the pair — formally known as Arp 273 — can be attributed to a close encounter of the galactic kind; something that occurs frequently throughout intergalactic space. The swatches of blue are high-mass, hot, blue-white stars, which emit large quantities of ultraviolet radiation. Many of which, were formed after the galaxies briefly interacted, jostling up the raw materials for star formation, ultimately collapsing to form proto-stars.
The larger galaxy of the two, GC 1810, is estimated to be about five times more massive than its companion (UGC 1813), though, at a cursory glance, it looks much smaller than that. Despite the obvious difference in mass, the smaller galaxy likely contributed a considerable amount of said materials after it dived deep (yet off-center) into UGC 1810, before swooping around behind the galactic bulge, and ultimately emerging on the other side.
Afterwards, the tidal bridge of materials that connect both galaxies formed. Amazingly, despite the fact that both appear to be very close together, they are actually separated by tens of thousands of light-years. However, over the course of the next few hundreds of millions of years, the gravitational dance will continue, before the new, larger galaxy emerges.
The image, which was released in homage to the Hubble Space Telescope’s 21st year in orbit, is a composite, put together using images taken at various wavelengths. Specifically, the three filters on board Hubble, most importantly the Wide Field Camera 3, captured a broad range of wavelengths, from ultraviolet to the bluer and more reddish portions of the electromagnetic spectrum.