Pencil Nebula

The Pencil Nebula, also known as NGC 2736, is part of the Vela Supernova Remnant, located near the Vela Pulsar. The nebula's linear appearance triggered its popular name. It is thought to have been formed from part of the shock wave of the larger Vela Supernova Remnant. The Pencil Nebula is moving at roughly 644,000 kilometers per hour (400,000 miles per hour). The nebula is currently 0,75 light years in diameter.

During the initial stages of the supernova explosion, the shockwave moved through space at a rate of millions of kilometers per hour. It was slowed down by the gas of the interstellar medium, creating the extraordinary fog-like ripples observed.

The initial shockwave heated the gas in the nebula to a temperature of millions of degrees. The cooler areas glow red due to hydrogen emission. Some areas of the nebula are still so hot that they can be seen glowing blue with ionized oxygen atoms. In these areas the temperature is still at least thousands of degrees.