Hint: It's not a brain. Solution below!
This image shows a cross-sectional snapshot of a simulated supermassive star going supernova, approximately one day after the star's interior began expanding outward. The star's helium core can be seen powering fluid instabilities and the mix of heavy elements throughout the star's interior.
This image is the work of researchers led by UC Santa Cruz astrophysicist Ke-Jung Chen, and is featured in a paper published in a recent issue of The Astrophysical Journal. For more info on their work, and its implications for detecting traces of these stars, check out Nicole Sharpe's writeup over at FYFD.