What is astrometry?
Q: What is astrometry?
A: Astrometry is a part of astronomy that has to do with measuring the motion of objects in space such as stars.
Q: What are two main ways to measure these objects?
A: Two main ways to measure these objects are proper motion and parallax.
Q: How is proper motion measured?
A: Proper motion is measured by looking towards the same place at different times and seeing how far the star has moved, usually measured in arcseconds per year. When a star has a large proper motion, it usually means that it is nearby.
Q: How does parallax work?
A: Parallax is the apparent difference in position of an object when seen from two or more different places. When an object is seen from a new place, there is a new line of sight going from the viewer to the object showing a different background in the distance. Parallax can also be used to measure distances to the nearest few thousand stars, usually measured in parsecs which are equal to about 3.26 light years.
Q: What star has the largest proper motion?
A: Barnard’s Star has the largest proper motion, only moving 1 degree across the sky (3600 arcseconds) in 348 years.
