What does the word star mean in a scientific term?

Have there been manned missions to the outer planets? Do Extraterrestrials really exist? What is the the least count of sextant? Why your shadow changes during the day? What factors that affect the atmosphere? How many solar systems are there in the universe? What was sir john Franklin's motivation to explore? What characteristic of the atmosphere stays the same? Where do space stations get there source of power? What did Apollo 11 bring back from the space? Can you tell if you had intercourse? What was the biggest nuclear explosion? How long would it take to know the sun has burned out? If you weigh 89 pounds how much would you weight on Jupiter? Why do some Stuhrling watches have 39 days on their date dial? What word names the science study by astronomers? What kind of candles last the longest? What did Yuri Gagarin do that only dogs had done before? What would cause balloon to expand if taken to the top of a mountain? How can space exploration improve medical industry?