Mostafa11-2017 Geminga

Mostafa11-2017 Geminga

Image of the pulsar Geminga and its unnamed sister

High-energy photon emission around the pulsars Geminga and PSR B0656+14, as captured by the High-Altitude Water Cherenkov Observatory. The large extended clouds of photon emission are believed to contain energetic electrons and positrons. Because these pulsars are nearby, cosmically speaking (about 250 parsecs), they appear very large in the sky. If humans could see high-energy photons with the naked eye, these would dominate the sky as they are many times larger than the moon, which is shown to scale for a size reference.

IMAGE: High-Altitude Water Cherenkov Collaboration (moon image Gregory H. Revera)