So if you take a time series of images of an asteroid through the night or over several days
you will find that its brightness varies in a most periodic way.
Using some available processing tools and a spreadsheet, it is quite straight forward
to measure the asteroid's period of rotation.
I use AIP4Win or Canopus to get the asteroid magnitudes, and
I use Canopus or Peranso to determine the period of the asteroid.
The rotational period of asteroids is valuable information for the professional astronomers.
The "CALL" web site provides information that allows one to select a target asteroid, and
a place to submit your measured periods.
See - Measuring Asteroid Periods: Methods & Tools
PERANSO
CANOPUS
AIP4Win
