The Digital Press

Researchers analyzed near-infrared spectra of 22 Type Ia supernovae to detect stable nickel-58, which reveals insights into explosion conditions and progenitor masses. They found the nickel line appears later in normal supernovae and earlier in subluminous ones, indicating dense burning near the center.

Why it matters: Detecting stable nickel-58 helps distinguish supernova explosion mechanisms and progenitor star characteristics.

The big picture: Central nickel-58 presence suggests high-density burning, supporting near-Chandrasekhar mass progenitor models for some Type Ia supernovae.

Stunning stat: Nickel line peak velocities are low (~1200 km/s) with narrow widths (≤3500 km/s), indicating centrally located nickel.

Quick takeaway: Subluminous SNe Ia show nickel features by ~+50 days; normal-bright SNe Ia show them only after ~+150 days.