The March 2005 issue mentioned a newly discovered stellar neighbor, SIPS 1259-4336. How do astronomers use parallax to determine if a star is a close neighbor of the Sun?
DAVID SALVIA, SANTA BARBARA, CALIFORNIA
The two images (above) that appeared in the news story "New star found near Sol" show the star's proper motion, not its parallax. Proper motion is the apparent movement of a star across the sky year after year. It results from both the star's movement through space and our own. In the same way, as you drive down the highway, nearby objects such as road signs appear to pass by fast, whereas distant objects such as mountains seem to move slowly. The two images of the new star were taken 10 years apart.