General · TV

Magneto’s star

Supernovas are mind-boggling. But supernovas are not all the same. For example, magnetars.

Like other neutron stars, magnetars are around 20 kilometres (12 mi) in diameter and have a mass 2–3 times that of the Sun. The density of the interior of a magnetar is such that a thimble full of its substance would have a mass of over 100 million tons.

The magnetic field of a magnetar would be lethal even at a distance of 1000 km due to the strong magnetic field distorting the electron clouds of the subject’s constituent atoms, rendering the chemistry of life impossible. [The “How the Universe Works” episode about supernovas that I watched today on TV said that “it would suck the iron out of your blood.”] At a distance of halfway from earth to the moon, a magnetar could strip information from the magnetic stripes of all credit cards on Earth. As of 2010, they are the most powerful magnetic objects detected throughout the universe.

It is estimated that about one in ten supernova explosions results in a magnetar rather than a more standard neutron star or pulsar.

3 thoughts on “Magneto’s star

  1. This seminar discusses the life cycle of black holes:

    Alan Weinstein, Professor of Physics (Physics, Mathematics and Astronomy)


    Black holes are the sites of the strongest gravitational fields in the universe. In pairs, they orbit each other, and the rapidly changing gravity produces vibrations of space itself, which travel to us as gravitational waves. As the pair loses all of its orbital energy, the two black holes merge into one, emitting an incredible burst of gravitational waves. LIGO (the Laser Interferometer Gravitational-Wave Observatory), operated by Caltech and MIT, have designed, built, and operated two huge detectors that can now “hear” these vibrations from the warped parts of the universe. Come listen! — Caltech | Alumni Reunion Weekend 2017 (80th Annual Seminar Day) Program

  2. This August 2, 2017, article “Rebel Supernova Formed in ‘Heavy Metal’ Galaxy” discusses research on superluminous supernovas.

    The researchers also investigated what makes SN 2017egm so bright. They concluded that the supernova may be powered by a rapidly spinning dead star called a magnetar. Such ultradense, spinning neutron stars created by supernovas could continue to generate magnetic power that would heat up the expanding gas left over from the supernova.

  3. Today (October 25, 2017), this article “Magnetic Fields Are the Unsung Workhorses of Astrophysics” caught my attention. It reminded me of how the Voyager space probes monitored magnetic fields in order to mark interstellar space.

    Galaxy clusters’ magnetic fields are particularly intriguing. For one, they completely fill up the volume of their host cluster. For those keeping score, that’s somewhere around 10^20 cubic light-years of nearly empty space. Despite their gargantuan size, those enormous magnetic fields are not perfectly smooth. They’re tangled and bent on the scale of tens of thousands of light-years. That means that, if you had a sufficiently sensitive compass, you could follow a single magnetic-field line for about the width of a galaxy before it would branch off into a new direction.

    … The answer might lie in the dynamos themselves, particularly the ones around supermassive black holes. These monstrous engines power active galactic nuclei. We see the intense radiation jetting away from these objects, and we know those jets are highly magnetized. Is it enough to completely fill up the enormous volume of galaxy clusters?

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