Conceptual

Near-IR Helium Constraint on the Superluminous Supernova SN 2024ahr

An observational determination that the hydrogen-poor superluminous supernova SN 2024ahr shows no He I 2.058 micron feature in a high-signal-to-noise near-infrared spectrum taken ~43 rest-frame days after peak, yielding a conservative upper limit of ~0.05 solar masses of helium in the outer ejecta. Combined with magnetar-powered light-curve modeling and Type-Ic-like Mg I / Co II-Mg II features at high velocity, the measurement constrains whether SLSN-I progenitors are helium-bearing (Ib-like) or helium-free (Ic-like) at explosion.