NGC 7578 is a pair of galaxies located in the constellation Pegasus. NGC 7578A (also Arp 170, MCG 3-59-24, UGC 12477 and PGC 70933) is a magnitude +13.9 spiral galaxy located 554 million light-years away. NGC 7578B (also Arp 170, MCG 3-59-25, UGC 12478 and PGC 70934) is a magnitude +14.0 elliptical galaxy located 553 million light-years away.
The galaxies were discovered by German-British astronomer William Herschel using a 47.5 cm (18.7 inch) f/13 speculum reflector at Observatory House, Windsor Road, Slough, Berkshire on the 18th September 1784.