Illustration of magnetized star (pulsar) with bursts of radiation from the poles. Image credit: NASA

Illustration of magnetized star (pulsar) with bursts of radiation from the poles. Image credit: NASA

Out in the far reaches of the galaxy lie hundreds of rapidly spinning and highly magnetized stars. Then, somewhat unexpectedly, the star surges with immense energy, spinning faster and bursts out intense radiation. This is a star quake. Literally, an earthquake, but on a very dense spinning star!

Star quakes, or star glitches, according to Kouveliotou, Duncan & Thompson in 2003, are the source of gamma ray flares that occur about once every decade. There are currently two theories for the mechanism behind what makes these stars tick off!

Theory #1: Huge stresses exerted on the star's surface produced by twisting of the ultra-strong magnetic fields.

Theory #2: Spindown, or relaxation, could cause dragging of the surface, essentially bleeding off energy and re-shaping its surface. This is possibly on the order of micrometer changes in less than a millionth of a second!

In December 2004, the largest star quake was recorded from SGR 1806-20 with a magnitude roughly equal to an earthquake magnitude 32!

 Illustration of pressure points and oscillations on the surface of a star. Image credit: University Birmingham

Illustration of pressure points and oscillations on the surface of a star. Image credit: University Birmingham

Thank you for reading and come back next week for a look at another mysterious moon of Saturn!