Sun-as-a-star Analysis of H? Spectra of a Solar Flare Observed by SMART/SDDI: Time Evolution of Red Asymmetry and Line Broadening

Stellar flares sometimes show red/blue asymmetries of H$\alpha$ line, which can indicate chromospheric dynamics and prominence activations. However, the origin is not completely understood. For a deeper understanding stellar data, we performed Sun-as-a-star analysis line profiles an M4.2-class solar flare showing dominant emissions from ribbons by using data Solar Dynamics Doppler Imager onboard Magnetic Activity Research Telescope at Hida Observatory. The spectra red asymmetry up to $\sim$95 km s$^{-1}$ broadening $\sim$7.5 {\AA}. are consistent with regions weak intensity, but they take smaller redshift velocities widths factor $\sim$2 than those strong intensity. velocities, as well widths, peak out decay more rapidly equivalent condensation model spatially-resolved spectra. This suggests that result superposition, nature observable even time evolution found be similar luminosities near-ultraviolet rays (1600 {\AA}), while optical white lights. These spectral behaviors in view could helpful distinguish whether ribbon or other phenomena.