Astronomers have discovered a new globular cluster.

He is world-famous as an astronomer.

He is a famous author and a person who is respected by many people.

The Earth is not perfectly spherical.

The time has come to start a new challenge.

Observing star clusters is a very important task for astronomers.

He discovered a new star.

He discovered a new star.

He was the first discoverer of that new species of plant.

An open cluster is a cluster of stars that consists of dozens to thousands of stars.