SN 2017egm: A Helium-rich Superluminous Supernova with Multiple Bumps in the Light Curves
SN 2017egm: A Helium-rich Superluminous Supernova with Multiple Bumps in the Light Curves
When discovered, SN~2017egm was the closest (redshift $z=0.03$) hydrogen-poor superluminous supernova (SLSN-I) and a rare case that exploded in a massive and metal-rich galaxy. Thus, it has since been extensively observed and studied. We report spectroscopic data showing strong emission at around He~I $\lambda$10,830 and four He~I absorption lines in …