Andy Briggs
Three connected boxes with what looks like different configurations of galaxies and voids inside.

What is dark energy?

Dark energy is one of the great unsolved mysteries of cosmology. It’s now thought to make up 68% of everything in the universe.

A ball of stars: globular cluster M13

What is a globular cluster?

Globular clusters are spherical collections of up to perhaps a million stars, orbiting mostly in the star halo of spiral galaxies, containing some of a galaxy’s oldest stars.

Airy-looking, cosmic-looking painting, dotted with round holes of various sizes.

What is dark matter?

Dark matter doesn’t emit light. It can’t be directly observed with any of the existing tools of astronomers. Yet astrophysicists believe that it and dark energy make up most of the mass of the cosmos. What dark matter is, and what it isn’t. here.

A white ball representing a star, with distorted-looking lines around it.

What is a neutron star?

Neutron stars are born in supernova explosions. They are stars with a couple of times our sun’s mass, squeezed into a sphere the size of an earthly city.

A black hole surrounded by magnetic fields and an accretion disk.

What is astrophysics?

Observational astronomy and astrophysics work together to further our understanding of the cosmos. Astrophysicists apply the laws of physics and physical theories to interpret the light gathered by observational astronomers.

Yellow-orange donut shape against a black background.

What are black holes?

Black holes are among the most bizarre and enigmatic objects in the modern universe. Click in for a black hole introduction.

A bright red star on the left. A slightly dimmer red star on the right.

Betelgeuse: What’s up?

The red supergiant star Betelgeuse, a bright star in the constellation of Orion, has been making headlines due to a recent drop in brightness. Is an explosion imminent? If it happens, will Earth be affected?

What is the asteroid belt?

The asteroid belt is a region of our solar system – between the orbits of Mars and Jupiter – in which many small bodies orbit our sun. Here’s a good basic introduction.

The location of the neutron star at the core of the supernova 1987A remnant. Via Cardiff University.

Astronomers find ‘missing’ neutron star after 32 years

Thirty-two years ago, Supernova 1987A erupted in the nearby Large Magellanic Cloud. Astronomers using the ALMA radio telescope now say they’ve found the small, compact neutron star created in this mighty star explosion.