100 billion times more luminous than the Sun
Arp 256 is a system of two barred spiral galaxies in the early stages of colliding and merging, located about 350 million light-years away at the western end of the constellation of Cetus ( the Whale ). The system is a luminous infrared system radiating more than a hundred billion times the luminosity of our Sun.
Despite the large separation of the galaxies’ nuclei, the two galaxies are strongly disrupted. The strong interaction between the galaxies is responsible for an astonishing number of blue knots of star formation.
The galaxy on the right (MCG-02-01-052) consists possibly of two overlapping galaxies, and the large galaxy to the left (MCG-02-01-051) has two very notable extended ribbon-like tidal tails of gas, dust and stars. Some of these super hot blue stars may really not be related to the galaxy itself.
It is the 256th galaxy in Arp’s Atlas of Peculiar Galaxies, which is a catalog of 338 peculiar galaxies produced by Halton Arp.
Image Credit: A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA