Chromospheric activity on late-type star LQ Hya

We present new high-resolution echelle spectra of LQ Hya to study its chromospheric activity. We analyzed our spectroscopic observations including several optical indicators of chromospheric activity (the He i D3, Na i D1, D2, Hα, and Ca ii infrared triplet lines), by means of the spectral subtraction technique. All the chromospheric activity indicators (the Na i D1, D2, Hα, and Ca ii IRT lines) confirmed chromospheric emissions. The ratio of EW8542/EW8498 for LQ Hya is around 1.5, which indicates that there is optically thick emission in a plage-like region. As for the Ca ii IRT and Hα lines, it seems that there is also a weak rotation modulation of chromospheric activity in our data, which might be explained by the strong plage or flare. The contemporaneous monitoring of photospheric and chromospheric emissions for LQ Hya indicate chromospheric plages might spatially associated with the spots.