The stars in a CCD image include stars in a cluster and stars in front of the cluster (i.e. starts that don't belong to it). One group has parallaxes clustered around of 3 milli-seconds of arc (or "3 mas"). The parallaxes of the other group range from 10 mas to 15 mas. Which group contains the stars in the cluster? Explain your answer.

What is the parallax angle of a star that is 50 pc away? enter your answer in arc seconds

3 4 Suppose that someone in the Andromeda galaxy had a super-telescope through which they were looking at Earth right now. They would see Earth A B C D B As it was about 2 ½ million years ago C As it was about 100,000 years ago Which of the following statements about stellar parallax is true? As it will be about 2 ½ million years from now A We observe all stars to exhibit at least a slight amount of parallax. E As it is right now Stellar parallax was first observed by ancient Greek astronomers. The amount of parallax we see depends on how fast a star is moving relative to us. D It takes at least 10 years of observation to measure a star's parallax. The closer a star is to us, the more parallax it exhibits.