We present a detailed analysis of the progenitor and its local environment for the recently discovered Type II supernova (SN) 2024ggi at a distance of about 6.7 Mpc, by utilizing the pre-explosion images from the Hubble Space Telescope and Spitzer Space Telescope. The progenitor is identified as a red bright variable star, with absolute F814W-band magnitudes being −6.2 mag in 1995 to −7.2 mag in 2003, respectively, consistent with that of a normal red supergiant star. Combining with the historical mid-infrared light curves, a pulsational period of about 379 days can be inferred for the progenitor star. Fitting its spectral energy distribution with stellar spectral models yields the stellar parameters of temperature, radius, and bolometric luminosity as T*=3290−27+19 K, R*=887−51+60 R _⊙, and log(L/L _⊙) =4.92−0.04+0.05 , respectively. The above parameters indicate that the progenitor of SN 2024ggi is consistent with the stellar evolutionary track of a solar-metallicity massive star with an initial mass of 13−1+1 M _⊙. Moreover, our analysis indicates a relatively low mass-loss rate (i.e., <3 × 10⁻⁶ M _⊙ yr⁻¹) for the progenitor compared to that inferred from flash spectroscopy and X-ray detection (i.e., 10⁻²–10⁻⁵ M _⊙ yr⁻¹), implying a significant enhancement in mass loss within a few years prior to the explosion.

中文翻译：

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II型超新星2024ggi的红超巨星前身


我们利用哈勃太空望远镜和斯皮策太空望远镜的爆炸前图像，对最近发现的距离约 6.7 Mpc 的 II 型超新星 (SN) 2024ggi 的前身及其局部环境进行了详细分析。该前身被确定为一颗红色明亮变星，F814W带的绝对星等分别为1995年的-6.2星等和2003年的-7.2星等，与正常红超巨星的星等一致。结合历史中红外光变曲线，可以推断出祖星的脉动周期约为379天。将其光谱能量分布与恒星光谱模型拟合，得到温度、半径和测辐射热光度的恒星参数，如 T*=3290−27+19 K、R*=887−51+60R _⊙ 和 log (L/L _⊙ )=4.92−0.04+0.05，分别。上述参数表明，SN 2024ggi的前身星与初始质量为13−1+1M _⊙ 的太阳金属丰度大质量恒星的恒星演化轨迹一致。此外，我们的分析表明，与推断的相比，祖先的质量损失率相对较低（即 <3 × 10 ⁻⁶ M _⊙ yr ⁻¹ ）来自闪光光谱和 X 射线检测（即 10 ⁻² –10 ⁻⁵ M _⊙ yr ⁻¹ ），意味着显着增强爆炸前几年内的质量损失。