Protostars are observable by radio telescopes but hard to detect in visible light because they have _____ and are ____.
A) low surface temperature; very distant
B) small size; very hot
C) low surface temperature; surrounded by dust
D) small size; very distant

Question

Quizplus · Accepted Answer

Protostars have low surface temperatures and are often surrounded by dense clouds of dust and gas, which absorb visible light but allow radio waves to pass through, making them detectable by radio telescopes.

Protostars Are Observable by Radio Telescopes but Hard to Detect