Something doesn't add up in the Chandelier Cluster, Hubble telescope finds — Space photo of the week

NGC 6723 is a globular cluster, an ancient inhabitant of the Milky Way galaxy. (Image credit: ESA/Hubble & NASA, A.

Sarajedini, G.

Piotto) Quick facts What it is: NGC 6723, the "Chandelier Cluster" Where it is: 27,000 light-years away, in the constellation Sagittarius When it was shared: June 26, 2026 In this single Hubble Space Telescope image, tens of thousands — possibly millions — of stars bound tightly by gravity sparkle as one.

This is NGC 6723, a glittering globular cluster about 27,000 light-years away, in the constellation Sagittarius.

Also known as the Chandelier Cluster, this swarm of stars is one of about 150 known globular clusters that orbit in the halo of the Milky Way, though others may remain hidden behind thick cosmic dust or crowded star fields at the galaxy's bright core.

Globular clusters like NGC 6723 are among the most ancient structures in our galaxy.

What baffles astronomers most is the age of the stars within them.

These clusters often contain stars older than 10 billion years, with some dating back almost to the beginning of the universe itself 13.8 billion years ago.

They likely formed early in the history of the Milky Way, billions of years before the thin disk of stars where the sun now orbits took shape.

It was once thought that all stars inside a globular cluster formed at the same time, from the same material, during a single burst of star formation.

If that were true, the stars would have the same age and chemical composition.

However, Hubble's view demonstrates that this is not the case.

The cluster is densely packed at the center, where many bright-blue stars appear concentrated, while orange stars are more prominent toward the edges.

Blue stars are younger than orange stars, suggesting that globular clusters can have complex histories, with different populations of stars and subtle chemical differences among them.