Early-phase Simultaneous Multiband Observations of the Type II Supernova SN 2024ggi with Mephisto
Abstract
We present early-phase good-cadence (hour-to-day) simultaneous multiband (ugi and vrz bands) imaging of the nearby supernova SN 2024ggi, which exploded in the nearby galaxy NGC 3621. A quick follow-up was conducted within less than a day after the explosion and continued for ∼23 days. The uvg band light curves display a rapid rise (∼1.4 mag day‑1) to maximum in ∼4 days and absolute magnitude M g ∼ ‑17.75 mag. The postpeak decay rate in redder bands is ∼0.01 mag day‑1. Different colors (e.g., u ‑ g and v ‑ r) of SN 2024ggi are slightly redder than SN 2023ixf. A significant rise (∼12.5 kK) in blackbody temperature (optical) was noticed within ∼2 days after the explosion, which successively decreased, indicating shock break out inside a dense circumstellar medium surrounding the progenitor. Using semianalytical modeling, the ejecta mass and progenitor radius were estimated as 1.2 M ☉ and ∼550 R ☉. The archival deep images (g, r, i, and z bands) from the Dark Energy Camera Legacy Survey were examined, and a possible progenitor was detected in each band (∼22–22.5 mag) and had a mass range of 14–17 M ☉.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2024
- DOI:
- 10.3847/2041-8213/ad62f7
- arXiv:
- arXiv:2405.07964
- Bibcode:
- 2024ApJ...971L...2C
- Keywords:
-
- Supernovae;
- Core-collapse supernovae;
- Type II supernovae;
- Red supergiant stars;
- Circumstellar matter;
- 1668;
- 304;
- 1731;
- 1375;
- 241;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Pages 12, Table 1, Figures 7