Hubble images spiral galaxy with a bulge rotating perpendicular to its disk

By the Everything Space news desk · 18 Sep 2026 · written from the sources below

Image: Phys.org

NGC 4698's mismatched inner structure offers clues to how galaxies evolve through mergers and gas accretion.

A new Hubble Space Telescope image shows NGC 4698, a spiral galaxy roughly 55 million light-years away in the constellation Virgo, part of the crowded Virgo Cluster that hosts more than a thousand galaxies bound by gravity.

At first glance, NGC 4698 resembles a typical spiral galaxy like the Milky Way, with dusty arms studded by young blue stars circling a glowing central bulge. But its arms are unusual in that they only appear in the galaxy's outer regions, forming a ring-like pattern rather than winding into the core as is common in most spirals.

The galaxy's bulge, made up of older, cooler stars orbiting a supermassive black hole with millions of times the sun's mass, is stretched out and tilted at a right angle to the surrounding disk. Observations show that the stars and gas near the center actually rotate perpendicular to the rest of the galaxy's disk, a rare configuration among spiral galaxies.

Astronomers believe the galaxy's off-kilter structure was likely caused by material flowing in from beyond its own boundaries. This external gas may have settled into a rotating structure at an angle to the original disk. A faint stream of hydrogen gas trailing from one side of the galaxy suggests it once underwent a minor collision with another galaxy, supporting the idea that outside interactions reshaped its core.

The image comes from a broader Hubble survey examining galaxies within the Virgo Cluster in fine detail, including their star clusters and gas clouds. Researchers hope the data will clarify how a galaxy's motion through a dense cluster environment influences its long-term evolution and capacity to form new stars.

Written in Everything Space’s own words by our news-desk model from the sources above, and checked against them in code: every number in this report appears in its sources, and no sentence is copied from them.