The purpose of the CALL web site is to allow those doing asteroid photometry and lightcurve work to to coordinate their efforts so that the best use of observing time can be made and to keep the asteroid community informed in a timely way.

Check, then Observe
Please use the Search page before you start work on a target, not after you have several sessions. This can help avoid unneccesary duplication. On the other hand, duplication is good if the new data are at a different phase angle or apparition or because the period cannot be effectively covered by one station or those of similar longitude.

There are thousands of asteroids within reach of backyard telescopes that have no lightcurve parameters at all and dozens that are wanting only good coverage at one more apparition for modeling. As more objects are covered, the statistical analysis of rotation periods, spin axes, and binary/tumbler populations will produce an improved picture of the system of minor planets.

CALL Site Functions

RegistrationRequired to submit notifications and lightcurve parameters

Edit RegistrationUpdate username , password, and/or other registration information

Lightcurve TargetsSelect targets and generate ephemerides based on year/month as well as limiting the range of magnitudes and declination.
Observing NotificationsLet others known what you're observing or ask for help

Lightcurve SubmissionsSubmit lightcurve parameters prior to publication

SearchSearch Notifications and Submissions.