NSVS 5222076 , a thirteenth magnitude star in the Northern Sky Variability Survey , was identified by Oaster as a possible new double-mode RR Lyrae star .
We confirm the double-mode nature of NSVS 5222076 , supplementing the survey data with new V band photometry .
NSVS 5222076 has a fundamental mode period ( P _ { 0 } ) of 0.4940 day and a first overtone period ( P _ { 1 } ) of about 0.3668 day , giving a period ratio of P _ { 1 } / P _ { 0 } = 0.743 .
In most double-mode RR Lyrae stars , the amplitude of the first overtone mode pulsation is greater than that of the fundamental mode pulsation .
That is not true for this star .
Its fundamental mode light curve has an amplitude twice as large as that of the first overtone mode , a ratio very rarely seen even among the double-mode RR Lyrae that do have relatively strong fundamental mode pulsation .
Data from the literature are used to discuss the location in the Petersen diagram of double-mode RR Lyrae stars having strong fundamental mode pulsation .
Such stars tend to occur toward the short period end of the Petersen diagram , and NSVS 5222076 is no exception to this rule .