The Red Supergiant Progenitor of Type II Supernova 2024ggi

Abstract

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.

Early-phase Simultaneous Multiband Observations of the Type II Supernova SN 2024ggi with Mephisto

“…However, in our investigation of the SN 2024ggi progenitor, the dust mass contribution has not been accounted for, and hence, some enhancement in the estimated mass limit is possible. Xiang et al (2024) found that the dust shell surrounding the SN 2024ggi progenitor is significantly optically thin (optical depth τ V = ∼0.3) than SN 2023ixf (τ V = ∼10-13; Neustadt et al 2024;Van Dyk et al 2024). This indicates very limited influence of dust on the SN 2024ggi progenitor's spectral energy distribution.…”

“…Recently, Xiang et al (2024) investigated the progenitor properties and the local environment of SN 2024ggi using the HST and Spitzer Space Telescope archival images. They derived an initial mass of the possible progenitor 13 ± 1 M e , which is consistent with our estimated lower mass limit (14 M e ).…”

“…This indicates very limited influence of dust on the SN 2024ggi progenitor's spectral energy distribution. It also implies that possibly there is a much thinner CSM shell around SN 2024ggi progenitor (Xiang et al 2024) in comparison to the dustiest SN 2023ixf progenitor (Van Dyk et al 2024).…”

Probing the Shock Breakout Signal of SN 2024ggi from the Transformation of Early Flash Spectroscopy

“…-+ R e(Xiang et al 2024). With the first-light date at MJD = 60411.03 ± 0.05 determined through high-cadence photometric observations (S. Yan et al 2024, in preparation), SN 20024ggi stands out as an SN II with extremely early photometric and spectroscopic observations(Tonry et al 2024;Zhai et al 2024).…”