This arXiv preprint (not yet peer-reviewed) reports 34 two-dimensional magnetohydrodynamic simulations of core-collapse supernovae using a 40 solar-mass progenitor star. The researchers varied initial magnetic field strength from zero to 3.5 × 10^12 Gauss and core rotation rates from zero to 0.5 rad/s, employing self-consistent neutrino transport. They identified four distinct outcomes: failed explosions that form black holes, monopolar jet-driven explosions, bipolar jet explosions, and neutrino-driven explosions without strong magnetic support.

Key finding: without any magnetic fields the 40-solar-mass star failed to explode in two dimensions even when spun rapidly. Rotation substantially lowers the magnetic-field threshold needed to launch an explosion, and both stronger fields and faster rotation produce quicker, more energetic outbursts that can reach diagnostic energies near 10^51 erg within hundreds of milliseconds—energetic enough to qualify as hypernovae and potential long gamma-ray burst progenitors.

The study’s gravitational-wave analysis shows that wave frequencies depend primarily on rotation rate and are relatively insensitive to magnetic-field strength or explosion morphology. However, the amplitude of the waves varies strongly with morphology and field strength, complicating template-based searches.

This work fills a gap previous studies largely missed. Earlier 3D MHD simulations (Mösta et al., arXiv:1406.3664) demonstrated jet formation in individual models but did not systematically map the morphology-to-waveform connection across a wide parameter space. Similarly, comprehensive gravitational-wave catalogs focused on neutrino-driven supernovae (Andresen et al., arXiv:1606.03300) under-represented the magnetorotational channel that dominates for rapidly rotating, strongly magnetized cores. By linking specific explosion shapes directly to detectable gravitational-wave characteristics, the new simulations help multimessenger astronomers distinguish jets from failed supernovae even when electromagnetic signals are obscured or absent.

Limitations must be noted: all models are two-dimensional, which can artificially organize flows and exaggerate certain instabilities compared with full 3D turbulence. Only one progenitor mass was explored, and the parameter grid, while impressive for a systematic study, remains a sparse sample of possible stellar conditions. Three-dimensional extensions will be essential before applying these waveforms to real detector data.

The broader pattern is clear: stellar death is not binary. Magnetic fields and rotation act as control knobs that decide whether a massive star ends in quiet black-hole formation, a lopsided jet, or a classical supernova. Future detectors such as the Einstein Telescope or Cosmic Explorer may therefore use these amplitude and frequency differences to map the fraction of stars that die as jets versus failures across cosmic time, refining our understanding of chemical enrichment, black-hole birth rates, and the engines behind long gamma-ray bursts.