What does "periastron" mean?

That point of the orbit of a celestial body which is closest to the star around which the body is orbiting.

How do you pronounce "periastron"?

Pronounced //pɛɹɪˈæstɹən//.

/pɛɹɪˈæstɹən/ noun

noun ·Rare ·Advanced level

Noun

1
That point of the orbit of a celestial body which is closest to the star around which the body is orbiting.

From Ancient Greek περί (perí, “around”) + ἄστρον (ástron, “star”).