Around a Dark Star: PSR 1257+12A, B, and C
The first exoplanets ever discovered (in 1992) are in some ways the strangest. They orbit a pulsar--a tiny, rapidly rotating neutron star left after a massive star dies and collapses. The planets are only dimly lit by the pulsar's weak glow, but the neutron star's intense radiation might cause vivid auroras, as depicted here. Whether these planets survived the original star's death blast or formed later is unknown.
R. Hurt/NASA