The Changing Lightcurve of the Double-Mode RR Lyrae Variable Star V338 Boo

Abstract

We present an analysis of the lightcurve extracted from Transiting Exoplanet Survey Satellite Full Frame Images of the double-mode RR Lyrae V338 Boo. We find that the fundamental mode pulsation is changing in amplitude across the 54 days of observations. The first overtone mode pulsation also changes, but on a much smaller scale. Harmonics and combinations of the primary pulsation modes also exhibit unusual behavior. Possible connections with other changes in RR Lyrae pulsations are discussed, but a full understanding of the cause of the changes seen in V338 Boo should shed light on some of the most difficult and unanswered questions in stellar pulsation theory, and astrophysics more generally.

arXiv comment8 pages, 4 figures, accepted to The Astrophysical Journal Letters

References in corpus (11)

• The Transiting Exoplanet Survey Satellite
• Northern Sky Variability Survey (NSVS): Public data release
• The Catalina Surveys Periodic Variable Star Catalog
• Search for Variable Stars in the Globular Cluster M3
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• Anomalous Double-Mode RR Lyrae Stars in the Magellanic Clouds
• Blazhko-type modulation in the double-mode RR Lyrae stars of the OGLE Galactic bulge collection
• Blazhko modulation in the infrared
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Cited by in corpus (4)

• First results on RR Lyrae stars with the TESS space telescope: untangling the connections between mode content, colors and distances
• Unveiling the Intricate Symphony of Nonlinear Pulsation Mode Interactions in High-Amplitude $\delta$ Scuti Stars
• Frequency analysis of the first-overtone RR Lyrae stars based on the Extended Aperture Photometry from the K2 data
• Caught in the Act: Observations of the Double-mode RR Lyrae V338 Boo During the Disappearance of a Pulsation Mode