A Crabby Pulsar in a Crabby Nebula

The Crab Nebula, as it’s commonly known, is connected to one of the earliest recorded supernova explosions.  In 1054 AD, Chinese Astronomers saw the explosion of this supernova as an incredibly bright star in the sky lasting about two weeks, before fading.  Now, nearly 1000 years later, the explosion is still happening as an expanding shock front rich in heavy elements moves through the interstellar medium.  When the shock front hits dust or gas it is slowed down, giving the resulting nebula a unique shape.  In this case, it looks like a crab.

The Crab Nebula. Credit: HST, NASA, ESA, J. Hester and A. Loll (Arizona State University)

The supernova wasn’t exactly the death of the original massive star.  After it exploded it became what is known as a Pulsar, an incredible dense neutron star that is spinning rapidly.  To put it in perspective, the pulsar is a star about 10 Km across, but it has 1.5 times the mass of the Sun packed in, and it’s spinning about 30 times a second! This spinning produced a magnetic field that makes the Sun look like a fridge magnet.

The rotation of this magnetic field causes electrons to be stripped off the surface of the pulsar, which accelerate outward and produce high energy beams.  When these beams face us we see a ‘pulse’ of energy, hence the name ‘pulsar.’

In 2011, the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) observatory detected photos with TeV energies (Terra electron volts).  For reference the energy of a visible photon from the Sun is between 2 and 5 eV, while this Pulsar is firing off photons 1 Trillion times as energetic.  These detected energies are higher than anything ever observed from a pulsar before.   In fact, they are so powerful that they challenge our current understanding of physics in these extreme scenarios.

MAGIC Spokeperson Razmik Mirzoyan from the Max Planck Institute for Physics (MPP) in Munich (Germany) says: “This is another very important result achieved by MAGIC on the puzzling celestial object, which incidentally besides the Sun is the most investigated one in all energy ranges. Hence from the beginning of operation of the MAGIC experiment in 2004, we have been intensively observing the Crab Nebula and the Crab pulsar. And that has really paid-off- in the mean time we revealed significant features of this enigmatic object thus providing substantial input to our theory colleagues- now it is their move to explain how the things are at work. MAGIC has been designed to be the most suitable instrument among imaging atmospheric Cherenkov telescopes to perform this kind of observations.”

Whatever is going on, it’s exciting to think about discovering some new Physics to explain what is happening.  Though it may just be some regular old Physics contributing in an unexpected way.  I guess this is exciting too.

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