Name/Affiliation: Dongtao Cao and Shenghong Gu (Yunnan Observatories, Chinese Academy of Sciences)
Prominence activity, flare and post-flare loops on the RS CVn-type binary SZ Psc
We present the results of time-resolved high-resolution spectroscopic observations of the very active RS CVn-type star SZ Psc, obtained during two observing nights in 2011 October 24 and 25. Several optical chromospheric activity indicators formed at different atmospheric heights were analyzed using the spectral subtraction technique, which show the remarkably different behavior and reveal a series of interesting magnetic activity phenomena in short period of time. Blue-shifted absorption feature presented in the subtracted spectra, as a result of cool prominence motion while seen in projection against the stellar disk, was found in the first observing night. This event was associated with the subsequently strong optical flare observed in our second observing night. The flare was characterized by the prominent He i D3 line emission, together with stronger chromospheric emission in several other active lines. An obviously developmental absorption feature was occurred on the blue wing of the Balmer line profiles accompanied by the gradual decay of flare, which can be explained as cool post-flare loops. Interestingly, a X-ray flare took place at the similar orbital phase was detected by using the Gas Slit Camera (GSC) of the Monitor of All-sky X-ray Image (MAXI) after a few days of our observations, suggesting that there is a long-lived active region over the surface of SZ Psc.