SUNSET: 
Loosening the Hubble Tension
New James Webb Space Telescope observations may have done with one of the longest-standing tensions in cosmology.
How to Define a Planet – The Sequel
Hold your breath: astronomers are re-evaluating their definition of a planet. Spoiler: it won’t bring Pluto back into the family.
Status Report: Gravitational Waves
Astronomers at the International Astronomical Union report that we have now detected more than 200 gravitational-wave events, most the merger of two black holes.
New Simulation Sheds Light on Black Hole Growth
New supercomputer simulations reveal the journey gas takes to enter a galaxy and surround and enter its black hole. That journey holds a few surprises for astronomers.
A Black Hole for Omega Centauri
The motions of individual stars in the core of Omega Centauri, a massive globular cluster, confirm the existence of a black hole at its core.
Wil Tirion, 1943–2024
Dutch astrocartographer Wil Tirion will be remembered as the creator of the most beautiful star maps and atlases of our time.
Rethinking the Milky Way’s “Galactic Fountain”
The Milky Way recycles gas from dying stars to make new ones — but new observations show pristine gas also comes in from outside our galaxy.
Gotcha: Firm Evidence for a Neutron Star in Supernova 1987A
After decades of debate, James Webb Space Telescope observations provide firm evidence of a neutron star inside the 1987A supernova remnant.
Astronomers Find "Big Ring" 1.3 Billion Light-Years Across
Standard cosmological scenarios might not explain the breadth of a newly discovered cosmic structure.
Astronomers Watch Another Giant Star Dim
Turns out, Betelgeuse isn't the only giant star to undergo a "Great Dimming."
Webb Telescope Peers into Puffy Planet with Clouds of Sand
A mere 200 light-years away, there's a planet with the density of styrofoam and clouds of sand. How did it get so weird?
New Cosmology Probe Presents First, Stunning Images
The Horsehead Nebula and other stunning scenes highlight the talents of the just-launched Euclid mission. The telescope will reach into the depths of the cosmos to understand dark matter and dark energy.
Ghost-like Galaxy Defies Dark Matter Model
Astronomers have discovered a large but very dim ghost-like galaxy. Its existence challenges our notions of dark matter.
Largest-ever Computer Simulation of the Universe
The Flamingo simulations are not only the largest but also the most all-encompassing simulations of the universe, from 13.75 billion years ago to today.
Surf’s Up: Waves Might Be Breaking on This Star
An unusual star system that brightens and fades every month might have giant plasma waves breaking on its surface.
Does the Hyades Star Cluster Harbor Black Holes?
The nearest black holes might be hiding just around the corner, 150 light-years away in the Hyades star cluster.
Astronomers Find Mysterious, Slowly Pulsing Star
An unidentified source has been beaming out a pulse of radio waves every 22 minutes since 1988.
Gravitational Waves from Supermassive Black Holes Revealed
Radio observatories across the globe have found compelling evidence for the existence of very-low-frequency gravitational waves.
Mystery Bursts Give Astronomers a View into Galaxy Halos
Flashes of radio waves — whose exact sources are still a bit of a mystery — are helping astronomers learn about the hot gas that surrounds the Milky Way.
The First Stars Weren’t Born Alone
New evidence suggests the first stars to shine in the universe formed in groups.
