RR Lyrae Observing Program

The RR Lyrae Stars observing program is administered by the Chair of the AAVSO RR Lyrae Stars Committee, under the auspices of the AAVSO Director and Council. The purpose of this program is to monitor the visual behavior of RR Lyrae stars in order to determine or revise elements where necessary. There are currently 40 stars in the program, many of them of small amplitude. Stars may be added to the program as a result of general interest or at the request of an astronomer. Special finder charts for these stars are available.

Observers make their observations using the appropriate finder chart and according to a standardized procedure, and report their observations to the Chair in a standardized format. Strict adherence to observing procedures is necessary because of the small amplitude of variation of the stars. The data are reduced and archived in electronic form in the RR Lyrae Stars section of the AAVSO International Database. The unreduced observations (observer reports) are also archived, in both electronic and hardcopy format. Observations from the early years of the program's existence are being digitized; at present they exist only as hardcopy. Observations are available from AAVSO Headquarters or the Committee Chair on request. Plans are underway to publish times of maximum and O-C curves of a number of program RR Lyrae stars.

More Information

• Astronomy Picture of the Day - Beautiful movie of the varying RR Lyrae stars in the bright globular cluster M3
• Observed Maxima Timings of RR Lyrae stars
• RR Lyrae Bulletin
• RR Lyrae Charts recently placed online
• RR Lyrae Ephemerides
• RR Stars - Observing Procedures/Objectives
• Recommended Comp Stars For CCD Observers
• RR Lyrae Variable Stars of the Season