almost that time to leave

1. What are the four ways astronomers can detect extrasolar planets?
radical volocity, astrmetry, transit method, optical detection
2. Choose one of the four ways and explain it in detail.
the radical volocity is like the doppler effect i detect when something is moving closer or away from the planet/star.
3. In your answer to #2 you chose one way that astronomers detect extrasolar planets. Search the Internet to find how many extrasolar planets have been detected using this method.
42 extrasolar planets has been found