For original images go here and here.

Using the Hubble Space Telescope, astronomers have obtained a new high resolution image of the Crab Nebula, and by comparing it with earlier Hubble images taken in 1999/2000, and have been able to track the continuing expansion and evolution of this supernova remnant over a period now covering almost a quarter century.

The supernova itself became visible on Earth in 1054, though it actually erupted about 6,500 years earlier, as the Crab Nebula is 6,500 light years away. In the 25 years Hubble has been tracking the remnant’s expansion astronomers estimate it is expanding at about 3.4 million miles per hour.

[William Blair of Johns Hopkins University] noted that filaments around the periphery of the nebula appear to have moved more compared to those in the center, and that rather than stretching out over time, they appear to have simply moved outward. This is due to the nature of the Crab as a pulsar wind nebula powered by synchrotron radiation, which is created by the interaction between the pulsar’s magnetic field and the nebula’s material. In other well-known supernova remnants, the expansion is instead driven by shockwaves from the initial explosion, eroding surrounding shells of gas that the dying star previously cast off.

The new, higher-resolution Hubble observations are also providing additional insights into the 3D structure of the Crab Nebula, which can be difficult to determine from a 2D image, Blair said. Shadows of some of the filaments can be seen cast onto the haze of synchrotron radiation in the nebula’s interior. Counterintuitively, some of the brighter filaments in the latest Hubble images show no shadows, indicating they must be located on the far side of the nebula.

A movie showing the changes between these two images can be seen here. It is worth your while to take a look. These optical images will be further enhanced as the Webb Space Telescope gathers infrared data.