Crab Nebula’s Beating Heart is a Pulsing Dead Star
By Kyle Hill on May 29, 2014
You probably recognize the Crab Nebula. Thanks to the Hubble Telescope, the public has astounding pictures of what looks like an apple photographed mid-explosion, but is really the remnants of a star that fantastically exploded 1,000 years ago. What you won’t see in the photos of this cosmic corpse is its still beating heart.
When the central star in the Crab Nebula went supernova, it left something behind. What remained was an ultra-dense neutron star spinning at a fantastic rate—slightly over 30 times per second. As it spun, the neutron star emitted curiously regular pulses of radiation, corralled into tight beams by the star’s powerful magnetic fields. This “pulsar,” as it came to be known, was one of the first ever discovered. And if you look closer at these pulses, you can see something amazing.
The beating heart of the Crab Nebula isn’t fully understood, but the ripples in the nebula’s gas cloud seem to be caused by shock waves from the twisting of the neutron star’s magnetic field, says astrophysicist and communicator Katie Mack. Mack collaborated with educator Scott Lewis to produce the amazing GIF above (made using an animation by the Chandra X-Ray observatory team) and a video explaining the physics behind it.
Pulsars output so much energy that the Crab Nebula is classified as a “pulsar wind nebula,” where radiation slams in the gas surrounding the dead star, making the beautiful shock fronts. The environment around the pulsar gets violent enough that the stellar weather can change in a matter of days, not centuries or even millennia like other cosmic events.
“Not only is it mind-blowing in its own right, but we also get to observe [the pulsar’s] evolution within a timespan of years, instead of studying the aftermath and trying to wind back time through modeling,” Scott Lewis told me in an email.
Violent, chaotic stellar events are a boon for us astronomy enthusiasts. I could stare at that GIF for hours.
“This object is just so amazing that we wanted to feature it in a way that supplemented our live show and really deliver how fantastic the Universe really can be when looked at closely.”
Kyle Hill is the Science Officer of the Nerdist enterprise. Follow the geekery on Twitter @Sci_Phile.