UGC 1840, also known as Arp 145, are a pair of interacting galaxies located 250 million light-years away from the Solar System in the Andromeda constellation.

[2] The earliest known reference to the pair of galaxies is in part 2 of the Morphological Catalogue of Galaxies, published in 1964, where it is listed as MCG +07-06-002.

[7][8] With a diameter of 1.3 arc minutes, close to 100,000 thousand light-years, they are roughly the same size as the Milky Way.

Both galaxies are listed as Arp 145 in the Atlas of Peculiar Galaxies which was created by Halton Arp.

[10][11] They fall under the category of objects that have emanating material and both classified as galaxies that have ring systems.