Using Gamma Ray Monitoring to Avoid Missing the Next Milky Way Type Ia Supernova

Understand

A Milky-Way Type Ia Supernova (SNIa) could be unidentified or even initially unnoticed, being dim in radio, X-rays, and neutrinos, and suffering large optical/IR extinction in the Galactic plane.

• But SNIa emit nuclear gamma-ray lines from $^{56}{\rm Ni}\to ^{56}{\rm Co}\to ^{56}{\rm Fe}$ radioactive decays.
• These lines fall within the Fermi/GBM energy range, and the $^{56}{\rm Ni}$ 158 keV line is detectable by Swift/BAT.
• Both instruments frequently monitor the Galactic plane, which is transparent to gamma rays.