Chromospheric activity on the late-type star V1355 Ori using Lijiang 1.8-m and 2.4-m telescopes

• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2016,（10）
• 页码范围: 27-34
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-4527/16/10/153

摘要

We obtained new high-resolution spectra using the Lijiang 1.8-m and 2.4-m telescopes to investigate the chromospheric activities of V1355 Ori as indicated in the behaviors of Ca Ⅱ H&K,Hδ,Hγ Hβ,Na Ⅰ D1,D2,Hα and Ca Ⅱ infrared triplet (IRT) lines.The observed spectra show obvious emissions above the continuum in Ca Ⅱ H&K lines,absorptions in the Hδ,Hγ Hβ and Na Ⅰ D1,D2 lines,variable behavior (filled-in absorption,partial emission with a core absorption component or emission above the continuum) in the Hα line,and weak self-reversal emissions in the strong filled-in absorptions of the Ca Ⅱ IRT lines.We used a spectral subtraction technique to analyze our data.The results show no excess emission in the Hδ and Hγ lines,very weak excess emissions in the Na I D1,D2 lines,excess emission in the Hβ line,clear excess emission in the Hα line,and excess emissions in the Ca Ⅱ IRT lines.The value of the ratio of EW8542/EW8498 is in the range 0.9 to 1.7,which implies that chromospheric activity might have been caused by plage events.The value of the ratio EHα/EHβ is above 3,indicating that the Balmer lines would arise from prominence-like material.We also found time variations in light curves associated with equivalent widths of chromospheric activity lines in the Na Ⅰ D1,D2,Ca Ⅱ IRT and Hα lines in particular.These phenomena can be explained by plage events,which are consistent with the behavior of chromospheric activity indicators.