In 1853 he left government service and devoted himself to studying astronomy.
He moved to Berlin in 1862 to study astronomy.
There, he worked as a math teacher, but found time to study astronomy.
By eight, he was studying astronomy during his free time.
"This human person may well have studied astronomy, but what can she tell us about matters here in the Core?"
I've seen his letter of application to study astronomy.
While working in the new observatory, studied astronomy under him.
A person who studies astronomy is called an astronomer.
After all, I wasn't sent here to study astronomy.
He decided to study astronomy just before he started at university.