In order to attend the conference, two steps must be completed:

 Pre-registration and, if desired, abstract submission to be done by filling the appropriate on-line form. When filling this form, you will choose a login to access your private area on the conference website (ao4elt.lesia.obspm.fr)

Note: The pre-registration form no longer accepts abstract submissions. To submit a post-deadline paper, please contact the LOC.

 Final registration and Payment, to be done on an external website, hosted by the University of Victoria, which has its dedicated private area and login identification. You are advised to use the same login on both website (conference and payment).