NGC 4559

NGC 4559 is an intermediate spiral galaxy with a weak inner ring structure in the constellation Coma Berenices. Its velocity with respect to the cosmic microwave background is, which corresponds to a Hubble distance of. However, 26 non-redshift measurements give a much closer distance of. It was discovered by German-British astronomer William Herschel on 11 April 1785.
NGC 4559 is a member of the Coma I Group.

Supernova

One supernova has been recorded in NGC 4559: SN 1941A was discovered by Rebecca Jones on 24 February 1941, and after checking previous photographs of the galaxy, it was determined that the supernova was visible starting 5 February 1941.

Luminous Blue Variable

NGC 4559 is home to the luminous blue variable AT2016blu. It was discovered by the Lick Observatory Supernova Search on 11 January 2012. It experiences repeated supernova-like outbursts: first when discovered, then again in 2014, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2024, 2025, and 2026.