HEAVY METAL IN SPACE: NGC 6496

They contain a higher proportion of metals (heavier elements other than hydrogen and helium) than stars in similar clusters. This glowing region is NGC 6496, a globular cluster about 10 billion years old, and the stars in it are quite special. Not only are they rich in metals, but some of them also exhibit variable star properties. This means that the brightness of these stars changes over time.

NGC 6496 hosts long-period variables, which are giant, pulsating stars whose brightness can take up to a thousand days to change, and short-period eclipsing binaries, whose brightness decreases when eclipsed by a companion.

The brightness variations of these stars provide important information about their masses, radii, luminosities, temperatures, compositions and evolution, and allow astronomers to make measurements that are difficult or impossible to obtain with other methods.

Image description:

Glowing stars of different sizes almost completely cover the darkness of space in this image. Most of the stars emit an eerie bluish glow, while some are yellow. Diffraction spikes can be seen on some stars.