The AAVSO International Database is a precious resource for the science of variable star astronomy, and we hope your research will benefit greatly from the use of these data. The amateur and professional astronomers who have contributed data to the AAVSO over the last century did so hoping to make a positive contribution to variable star research, and it is our goal to facilitate the use of these data by the astronomical community. AAVSO data are and always will be provided free of charge upon request, as a service to the scientific community.
Our only requirements for the use of AAVSO data are simple:
First, please acknowledge the use of any and all AAVSO data used in publications with the appropriate acknowledgements  we have provided on our webpage. If the data form the basis of your research, we ask that a representative of the AAVSO be included as an author; in exchange we will assist you in the analysis and interpretation of these data at a level appropriate for a coauthor. And please use the AAVSO facilities keyword in any journal publications.
Second, if you use our data in a publication, please let us know! We are thrilled to see the work of our observer community in print, and our observers are equally thrilled to see their work put to good use. The AAVSO has created the AAVSO In Print  page for just this purpose. It shows the observers that their work is paying off, it showcases your hard work in using and analyzing AAVSO data, and it proves to the astronomical research community that the AAVSO continues to be a relevant and valuable resource for variable star astronomy. If your paper is accepted, in press, or published in a magazine, journal, or conference proceedings, please email us at firstname.lastname@example.org  with the paper title, the authors, the year of publication, and the journal and reference information. If the paper appears on the arXiv.org preprint server , please include the URL for the abstract page.
We are very pleased to provide you with whatever data we have of interest to you. If our data prove valuable to your research, please let us know!
Dr. Arne A. Henden, Director
American Assocation of Variable Star Observers