2026-09-08 中国科学院（CAS）
Absolute-magnitude UBVgr-band light curves of SN 2021pfs and SN 2011fe, together with the UBV-bandlight curves of SN 2011by. The bottom panel plots the magnitude difference (SN 2011fe-SN 2021pfs) in each band. (Image by XAO)
＜関連情報＞
- https://english.cas.cn/newsroom/research-news/202609/t20260908_1192808.shtml
- https://link.springer.com/article/10.1007/s11433-026-2999-3
SN 2021pfs：双子星との比較から明らかになった、前駆星の金属量の影響を受けている可能性が高いIa型超新星 SN 2021pfs: A type Ia supernova likely affected by progenitor metallicity, as revealed by comparison with its twin counterpart
Abdusamatjan Iskandar,Xiaofeng Wang,Ali Esamdin,Wenxiong Li,Xiangyun Zeng,Ruifeng Huang,Maokai Hu,Guoliang Lü,D. Andrew Howell,Curtis McCully,Samuel Wyatt,Daichi Hiramatsu,Estefania Padilla Gonzalez,Craig Pellegrino,Megan Newsome,Lluís Galbany,David J. Sand,Nathan Smith & Huei Sears
Science China Physics,materials & Astronomy Published:27 July 2026
DOI:https://doi.org/10.1007/s11433-026-2999-3
Abstract
We present extensive photometric and spectroscopic observations of the normal type Ia supernovae (SNe Ia) 2021pfs, which occurred in the Seyfert 2 galaxy NGC 5427 at a redshift of 0.009. SN 2021pfs reached an absolute B-band peak magnitude of Mmax(B) =−19.28 ± 0.40 mag and a post-peak decline rate of Δm15(B) =1.13 ± 0.06 mag. The observed properties of this nearby SN Ia closely resemble those of SN 2011fe, including the main optical spectroscopic features and photometric evolution. Despite their similar decline rates, SN 2021pfs rose more rapidly in the U band but more slowly in the r and i bands compared to SN 2011fe in very early phases. This photometric difference, particularly at short wavelengths, can introduce a systematic uncertainty of up to ∼12% in distance estimates. Analysis of the host galaxy’s local and global environment shows an environment consistent with producing a higher-metallicity progenitor for SN 2021pfs than that of SN 2011fe. This higher progenitor metallicity may explain the observed photometric discrepancy and the resulting distance between SN 2021pfs and SN 2011fe, though a larger sample of such “twin” SNe Ia is needed to confirm this trend and assess its impact on cosmological measurements.
