Two articles published in “The Astrophysical Journal” describing research on as many pulsar that allow to better understand the geometry of the plasma in their vicinity. Two independent team used NASA’s Chandra space telescope to study the pulsar Geminga, also known as PSR B0633+17, and PSR B0355+54 gathering information on the nebulas of high-energy particles called in jargon plerions generated by the pulsars.