Skip to main content



Secular Variation of the Mode Amplitude-Ratio of the Double-Mode RR Lyrae Star NSVS 5222076, Part II


David A. Hurdis
76 Harbour Island Road, Narragansett, RI 02882

Tom Krajci
P.O. Box 1351, Cloudcroft, NM 88317

Presented at the 100th Spring Meeting of the AAVSO, May 21, 2011; Received June 28, 2011; revised July 15, 2011; accepted July 15, 2011


We present results from our ongoing investigation of the double-mode RR Lyrae (RRd) star, NSVS 5222076, and specifically of the long-term temporal variation of the amplitude-ratio, A0/A1, of the star’s fundamental and first-overtone pulsation modes. Our earlier paper on this subject (Hurdis and Krajci 2010) described a seemingly monotonic decrease of the amplitude-ratio in the V band, from 1.93 in 2005 to 1.76 in 2008 to 1.48 in 2009. After further observation of the star during the 2010 and 2011 observing seasons, we report that the V-band amplitude-ratio continued to decrease to 1.40 in 2010, but then increased to 1.82 in 2011. This suggests that, rather than decreasing monotonically toward a switch of dominant pulsation mode, A0/A1 may be varying in an oscillatory manner.

link to article in ADS

AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484