AAVSO - The American Association of Variable Star Astronomers.
This well-known and respected amateur astronomy group has been collecting data on variable stars for over 95 years. This data is particularly useful for understanding the lifecycle and behavior of stars, and may even be useful for identifying planets outside our solar system.
Despite the importance of this data, professional astronomers are unable to spend the time needed to regularly watch these stars and analyze their brightness. AAVSO's stargazers already enjoy scanning the sky and this provides a valuable purpose to an enjoyable hobby.
AAVSO volunteers receive some brief training online and given the tools to accurately measure star brightness. After an evening of observations the data is sent to AAVSO headquarters where it is combined with nearly 100 years of data, and analyzed by scientists around the globe.
Getting Involved is Easy:
1) Visit www.AAVSO.org and learn more about this exciting group.
2) Review the AAVSO Manual for Visual Observing of Variable Stars available at http://www.aavso.org/publications/manual/. The manual is available in English, French, Spanish, Italian, and many other common languages.
3) Take your personal telescope into the backyard on a clear night with a pad of paper, pencil, and the star charts described in the manual.
4) Submit data to the AAVSO WebObs system. Only AFTER submitting the data, review the observations from other volunteers to see how yours compare. Use this as a learning tool to help "calibrate" your observer's eyes.
5) Take satisfaction in advancing the variable star data available for other scientists (or yourself!) to analyze.
Good luck, and enjoy!