The mean light curves of the Mira-type stars in the H- and K-bands

TL;DR

This study derives mean light curves for nine Mira-type stars and one semi-regular star in H and K bands, revealing correlations and symmetry in their near-infrared brightness variations.

Contribution

It provides detailed Fourier-based mean light curves and analyzes correlations between parameters in the H and K bands, including an unusual case of X Oph.

Findings

Mean light curves are generally symmetric in H and K bands.

Several correlations between Fourier parameters were identified.

X Oph shows an anomalous position in the parameter space.

Abstract

For nine Mira-type stars (o Cet, R Leo, S Car, U Her, X Oph, R Aql, RR Aql, S Ori, S Scl,) and one semi-regular star (L2 Pup), the mean light curves have been obtained. The initial values of the brightness (observations) were fitted by a trigonometric polynomial of the statistically optimal order. The Fourier coefficients and the additional parameters (degree of the trigonometric polynomial, amplitude of the brightness, the maximal slope of ascending and descending branch, semi-amplitudes and initial epochs for the brightness maximum (minimum magnitude) of each harmonic contribution, etc., were given in the tables reported earlier (Kudashkina, 2015). In this study, we have received several interesting correlations between these parameters in the bands H and K. It was particularly noted the anomalous position on the figures of the star X Oph. The mean light curves of the investigated stars are commonly symmetric in the near infrared region (H and K).