系外行星研究组知识库

We have obtained four Doppler images of LQ Hya in 2005 November-December, 2006 November-December, 2008 November, and 2014 January-February using high-resolution spectra obtained at three different observing sites. All of the surface maps show that the spots of LQ Hya are in bimodal distribution, i.e., in polar/high-latitude and low-latitude regions. Its chromospheric activity indicators exhibit obvious rotational modulations that are correlated with the simultaneous light curves, except in 2008. The correspondence between the maximum value of chromospheric emission and the low-latitude spot of new reconstructed image is clear, which indicates that both of them are driven by homologous magnetic field. The variation of H- alpha emission over a long time span suggests that the chromospheric plages may implicate a similar active cycle as photospheric spots.