DISTANCES TO NEARBY STARS
AND THEIR MOTIONS:
An Introductory Astronomy Lab
Measure the parallaxes of a few stars
In this section you will determine the distances to a number of stars
by measuring their parallaxes.
Instructions
- Each row represents one star field. The images are negatives:
bright objects appear black and vice versa.
- The left-most image was taken first; the middle image 6 months later.
- Identify which star has undergone a parallactic shift. You may find
the right-most image -- a blinking of the first two -- especially useful.
- Follow the link measure the star's parallax. Make sure to always click
on the center of the star's position while doing this part.
- The angle you measure represents twice the parallax angle. (See
section 2 of this lab: stellar parallaxes)
- Find the distance to the star in parsecs and light-years.
Questions:
- How accurate are your distances? (Measure the parallaxes a few times;
do you get the same distance each time? Is it worse for one star than the other?)
- Which star is closer?
- Based on their relative apparent brightnesses, which star is
intrinsically the brightest? Explain.
