Galaxies and clusters articles from across Nature Portfolio

Observations from the JWST MIRI-MRS instrument reveal the detection of rotational emission from molecular hydrogen near the only O-type star in the 3% solar metallicity galaxy Leo P, providing confirmation that significant quantities of molecular gas can form in such metal- and dust-poor environments.

It is widely believed that the Milky Way is set to collide with Andromeda, its nearest neighbour. New calculations using data from Hubble and Gaia that account for the effects of other galaxies show an almost 50% chance of our Galaxy avoiding this fate.

Gas distribution and motion patterns driven by a galactic bar of the J0107a dusty star-forming galaxy have analogues in local bars, indicating that similar processes of active star formation were already operating 11.1 billion years ago.

We demonstrate that in a major merging system, radiation from the quasar in one galaxy directly alters the gas properties in the companion galaxy.

Unexpected large-scale clustering of isolated, diffuse and blue dwarf galaxies, comparable to that seen for massive galaxy groups, challenges current models of cosmology and galaxy evolution.

As part of Black Space Week 2025, six extragalactic astronomers share information about their scientific interests, research projects and personal motivations for working in astronomy.

In the 100 years since Knut Lundmark established supernovae as a separate class, they have helped to expand our knowledge of the Universe.

As the Hubble Space Telescope celebrates its 35th year in orbit, this issue of Nature Astronomy includes two papers which mark JWST’s continued progress towards similarly reshaping our view of the cosmos. However, a proposed reduction to NASA's funding could delay or even prevent the launch of its next flagship space observatory.