APOD 3.6-NGC 1999: South of Orion

1,500 light years away, on the edge of the constellation of Orion, lies the reflection nebula called NGC 1999. The nebula appears to have a large sideways T-shape at its center. The entire NGC 1999 is about 10 light years wide.The dark T-shape is believed to be a hole that was formed through the nebula by the energy of young stars. Young stars within the nebula produce their luminosity from the powerful outflows of shock waves. V380 Orionis is a star within the nebula that provides NGC with its illumination. The red objects in the photo are shock waves named HH1 and HH2. Infrared images show that stellar jets of shock waves push through interstellar materials at hundreds of kilometers per second, forming large dark spots, along with the shock waves, like the ones seen in NGC 1999.