activity
20172026
most citedDo Kepler superflare stars really include slowly-rotating Sun-like stars ? - Results using APO 3.5m telescope spectroscopic observations and Gaia-DR2 data -

160 citations · 413 across the 19 of their papers we have counts for

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22 papers · 1 filter

astro-ph.SR2026

Systematic and Statistical Properties of Prominence Eruptions on the M-dwarf YZ CMi

Yuto Kajikiya, Kosuke Namekata, Yuta Notsu +4

M-dwarfs produce frequent flares, and their associated mass ejections are expected to significantly affect the habitability of close-in exoplanets. Recent spectroscopic observation…

astro-ph.SR2026

Multiwavelength Campaign Observations of a Young Solar-type Star, EK Draconis. III. Comparison between Starspot Mapping, Zeeman Doppler Imaging, and Multiwavelength Variability

Kai Ikuta, Kosuke Namekata, Pascal Petit +12

Recent simultaneous multiwavelength observations of a nearby young solar-type star EK Dra in the optical, H spectrum, and X-ray, have provided evidence for stellar prominence er…

astro-ph.SR2026

Statistical Study of Appearance Timing of H Postflare Loops: Simple Scaling Law Based on Radiative Cooling

Takato Otsu, Ayumi Asai, Kai Ikuta +1

Recent Sun-as-a-star studies have shown that postflare loops can manifest as a secondary peak in the H light curve, suggesting that stellar postflare loops are detectable. To un…

astro-ph.SR2025★ 4 cited

Doppler imaging combined with high-cadence photometry. I. Revisiting the surface of a pre-main-sequence flare star

Sanghee Lee, Engin Bahar, Hakan Volkan Şenavcı +11

Latitude distribution of stellar magnetic activity is not well constrained by observations, despite its importance for a better understanding of stellar dynamos. We aim to obtain a…

astro-ph.SR2025★ 7 cited

Do Young Suns Produce Frequent, Massive CMEs? Results from Five-year Dedicated Optical Observations of EK Draconis and V889 Hercules

Kosuke Namekata, Hiroyuki Maehara, Yuta Notsu +4

We report results from a five-year (132-night) dedicated observational campaign targeting two nearby young solar-type stars, EK Draconis (50-125 Myr age) and V889 Hercules ($…

astro-ph.SR2025

Time evolution of white-light flare accompanied by probable postflare loops on M-type dwarf EV Lacertae

Shinnosuke Ichihara, Daisaku Nogami, Kosuke Namekata +6

White-light flares are explosive phenomena accompanied by brightening of continuum from near-ultraviolet to optical, which occur on the Sun and stars. In order to investigate the m…