Solar flares are often accompanied by filament/prominence eruptions (~10⁴ K and ~10¹⁰⁻¹¹ cm⁻³), sometimes leading to coronal mass ejections that directly affect the Earth’s environment^1,2. ‘Superflares’ are found on some active solar-type (G-type main-sequence) stars^3,4,5, but the filament eruption–coronal mass ejection association has not been established. Here we show that our optical spectroscopic observation of the young solar-type star EK Draconis reveals evidence for a stellar filament eruption associated with a superflare. This superflare emitted a radiated energy of 2.0 × 10³³ erg, and a blueshifted hydrogen absorption component with a high velocity of −510 km s⁻¹ was observed shortly afterwards. The temporal changes in the spectra strongly resemble those of solar filament eruptions. Comparing this eruption with solar filament eruptions in terms of the length scale and velocity strongly suggests that a stellar coronal mass ejection occurred. The erupted filament mass of 1.1 × 10¹⁸ g is ten times larger than those of the largest solar coronal mass ejections. The massive filament eruption and an associated coronal mass ejection provide the opportunity to evaluate how they affect the environment of young exoplanets/the young Earth⁶ and stellar mass/angular momentum evolution⁷.

太阳耀斑通常伴随着灯丝/日珥爆发（~10 ⁴  K 和~10 ¹⁰⁻¹¹  cm ^-3），有时会导致直接影响地球环境的日冕物质抛射^1,2。在一些活跃的太阳型（G 型主序）恒星^3,4,5上发现了“超级耀斑” ，但尚未建立灯丝喷发-日冕物质抛射关联。在这里，我们展示了我们对年轻的太阳型恒星 EK Draconis 的光学光谱观察揭示了与超耀斑相关的恒星灯丝喷发的证据。^{这种超级耀斑发射出 2.0 × 10 33} erg的辐射能量 ，以及具有 -510 km s 高速的蓝移氢吸收成分不久之后观察到^{-1 。}光谱的时间变化与太阳灯丝喷发的时间变化非常相似。将这次喷发与太阳灯丝喷发的长度尺度和速度进行比较，强烈表明发生了恒星日冕物质抛射。喷发的灯丝质量为 1.1 × 10 ¹⁸  g，比最大的日冕物质抛射大十倍。大规模的细丝喷发和相关的日冕物质抛射提供了评估它们如何影响年轻系外行星/年轻地球⁶和恒星质量/角动量演化⁷的环境的机会。