Messier 90 (also known as M90 and NGC 4569) is an intermediate spiral galaxy exhibiting a weak inner ring structure about 60 million light-years away[a] in the constellation Virgo.

As a result of this process, which is referred to as ram-pressure stripping, the medium and star formation regions appear severely truncated compared to similar galaxies outside the Virgo Cluster[8] and there are even H II regions outside the galactic plane,[8] as well as long (up to 80,000-parsec—that is, 260,000-light-year) tails of ionized gas that has been stripped away.

[11] However, its center appears to host significant nebula and star formation, where around 50,000 stars of spectral types O and B that formed around 5 to 6 million years ago[12] are set amidst many A-type supergiants that were born in earlier starbursts, between 15 and 30 million years ago.

[15] The spectrum of Messier 90 is blueshifted, which indicates that, net of non-aligned vectors of motion, the gap between it and our galaxy is narrowing.

However, since the phenomenon was limited mostly to galaxies in the same part of the sky as the Virgo Cluster, it appeared that this inference based on the blueshift was incorrect.