Dr. Stella Kafka, Director of the American Association of Variable Star Observers (AAVSO), spoke to our club at the April 2018 public meeting. She told us about the different kinds of variable stars and how observing them is a rewarding scientific pursuit. Founded in 1911, amateur astronomers have contributed over 30 million observations to the AAVSO! Professional astronomers use the observations for many reasons, e.g., to schedule observations by the Hubble Space Telescope of a variable star during a particular phase of its activity. The AAVSO has a variety of observing sections, including exoplanets, eruptive variables, pulsating variables, young stellar objects, eclipsing binaries, and the sun. Headquartered in Cambridge, Massachusetts, the AAVSO has members from around the world.

Light Curve of Mira (omicron Ceti) - a long-period pulsating variable star

CREDIT: American Association of Variable Star Observers

Resources for observers – how to get started

• Equipment (your eyes, binoculars, DSLR, telescope, CCD…)
• Training materials:
• Manuals (visual, DSLR, CCD, solar, exoplanet) -- https://www.aavso.org/observing-manuals
• CHOICE courses (online training seminars – reduced rate for members) -- https://www.aavso.org/carolyn-hurless-online-institute-continuing-education-choice
• 10-star training tutorial -- https://www.aavso.org/10-star-training
• Stars Easy to Observe -- https://www.aavso.org/easy-stars
• Mentoring (membership benefit) – request a mentor at: https://www.aavso.org/mentor-program
  
• Sky charts with information on variable stars of interest and appropriate comparison stars-- https://www.aavso.org/apps/vsp/
  
• Possible targets – 
• AAVSO Target tool (register to get targets visible from your observatory’s location) https://www.aavso.org/aavso-target-tool 
• Target tool help at: https://www.aavso.org/aavso-target-tool-help 
• Also, AAVSO alerts can be found here: https://www.aavso.org/aavso-alert-notices-for-observing-campaigns-and-discoveries 
• Subscribe and receive our alerts in your inbox: https://www.aavso.org/aavso-alert-notice-subscribe
  
• Tools for observers:
  
• Light curve generator: https://www.aavso.org/LCGv2/
• VPhot (member benefit): to reduce CCD images and extract light curves: https://www.aavso.org/vphot
• VStar: light curve analysis; you can upload a light curve from your computer or from the AAVSO International Database: https://www.aavso.org/vstar
• Observing log (up to you – can be an excel spreadsheet, can be hand-written)
  
• Observer code: register on our web page and request your unique observing code at: https://www.aavso.org/apps/member/
  
• Submit data through WebObs: https://www.aavso.org/webob