Period Color and Amplitude Color relations for MACHO project LMC RR Lyraes

Abstract

In this paper, we analyze period color and amplitude color relations at minimum, mean and maximum $V$ band light for 6391 RRab stars in the Large Magellanic Cloud obtained by the MACHO project. Specifically, we find that color and amplitude are nearly independent of period at minimum light but that there exists a definite relation between period and color and amplitude and color at maximum light. These two properties are easily explained by the application of the Stefan Boltzmann law and the interaction of the photosphere and hydrogen ionization front at minimum light. When we examine the slope of the period color relation as a function of phase, we find that the slope varies significantly with phase and is small for a wide range of phases around minimum light. This suggests that another factor that needs to be considered when trying to understand RR Lyrae observed properties is their behavior at different phases during a pulsation cycle.

arXiv commentSumitted for publication to MNRAS Letters

References in corpus (7)

• The composition of HB stars : RR Lyrae variables
• The MACHO Project Large Magellanic Cloud variable star inventory. XI. Frequency analysis of the fundamental mode RR Lyrae stars
• RR Lyrae stars in Galactic globular clusters.III. Pulsational predictions for metal content Z=0.0001 to Z=0.006
• Period-color and amplitude-color relations in classical Cepheid variables
• The MACHO Project Large Magellanic Cloud Variable Star Inventory. XIII. Fourier Parameters for the First Overtone RR Lyrae Variables and the LMC Distance
• Identifying high redshift AGNs using X-ray hardness
• Period-colour and amplitude-colour relations in classical Cepheid variables II: the Galactic Cepheid model

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• On the variation of light curve parameters of RR Lyrae variables at multiple wavelengths
• Empirical Period-Color and Amplitude-Color Relations for Classical Cepheids and RR Lyrae Variables
• Period-Color and Amplitude-Color Relations at Maximum and Minimum Light for RR Lyrae Stars in the SDSS Stripe 82 Region
• Approximating RR Lyrae light curves using cubic polynomials