Simultaneous photometric and CARMENES spectroscopic monitoring of fast-rotating M dwarf GJ 3270

Context: Active M dwarfs frequently exhibit large flares, which can pose an existential threat to the habitability of any planet in orbit addition making said planets more difficult detect. do not lose angular momentum as easily earlier-type stars, maintain high levels stellar activity for far longer. Studying young, fast-rotating is key understanding their near environment and evolution Aims: We study on dwarf GJ 3270. Methods: analyzed dedicated cadence, simultaneous, photometric high-resolution spectroscopic observations obtained with CARMENES 3270 over 7.7 h, covering a total eight flares two are strong enough facilitate detailed analysis. consult TESS data, month prior our own observations, rotational modulation compare those observed campaign. Results: The data period 0.37 d. strongest flare covered by observing campaign released energy about 3.6e32 erg, putting it close superflare regime. This visible B,V, r, i, z bands, allows us determine peak temperature 10,000 K. also leaves clear marks spectral time series. In particular, we observe evolving, mainly blue asymmetry chromospheric lines, attribute post-flare, corotating feature. To knowledge this first such feature has been seen star other than Sun. Conclusions: Our series covers eruption followed up analogous post-flare arcadal loop Sun possible failed ejection material.