Astronomer (noun)

1. A person who studies the stars, planets, and other objects in space.
2. A specialist in the branch of science that deals with the observation and interpretation of celestial phenomena.

Origin:

Late middle english: from old french astronomie, from latin astronomia, from greek astronomia, from astronomos "star-observer", from astro- "star" + -nomos "arranger".

Examples:

1. The astronomer studied the night sky through the telescope.
2. The famous astronomer Galileo Galilei made many important discoveries about the solar system.
3. Astronomers use telescopes to observe distant stars and galaxies.
4. The astronomer's job is to study the universe and learn about its origins.
5. Many renowned astronomers have made significant contributions to the field of astronomy.