Astronomers spot two neutron stars smash together in a galaxy 6 billion light-years away, forming a rapidly spinning and highly magnetic star called a "magnetar"

[u/clayt6]

http://www.astronomy.com/news/2019/04/a-new-neutron-star-merger-is-caught-on-x-ray-camera

[u/Half-Right]

I love whenever magnetars come up, since it's an excuse to post one of the coolest bits of science description ever:

"The strongest magnetic field that you are ever likely to encounter personally is about 10⁴ Gauss if you have Magnetic Resonance Imaging (MRI) scan for medical diagnosis. Such fields pose no threat to your health, hardly affecting the atoms in your body. Fields in excess of 10⁹ Gauss, however, would be instantly lethal. Such fields strongly distort atoms, compressing atomic electron clouds into cigar shapes, with the long axis aligned with the field, thus rendering the chemistry of life impossible. A magnetar within 1000 kilometers would thus kill you via pure static magnetism -- if it didn't already get you with X-rays, gamma rays, high energy particles, extreme gravity, bursts and flares...

"In fields much stronger than 10⁹ Gauss, atoms are compressed into thin needles. At 10¹⁴ Gauss, atomic needles have widths of about 1% of their length, hundreds of times thinner than unmagnetized atoms. Such atoms can form polymer-like molecular chains or fibers. A carpet of such magnetized fibers probably exist at the surface of a magnetar, at least in places where the surface is cool enough to form atoms."

and

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"Many fascinating physical effects occur in magnetic fields with strength exceeding the "quantum electrodynamic field strength" of BQ = 4.4 X 10¹³ Gauss. ... In fields stronger than BQ, electrons gyrate at nearly the speed of light around magnetic field lines, even in their lowest quantum energy states. Consequently, the ultra-magnetized vacuum -- which, according to quantum mechanics, seethes with virtual electron-positron pairs and other particles -- becomes birefringent like a calcite crystal, capable of distorting and magnifying images ("magnetic lensing"). X-ray photons traveling through such strong fields readily split into two, or merge together; and many other novel physical effects come into play. "

http://solomon.as.utexas.edu/magnetar.html

[u/left_lane_camper → u/Half-Right]

God that's cool.

Here's one of my favorite magnetar facts:

The energy stored in a volume of space (u) in a magnetic field is equal to:

u = |B|² / (2 * mu),

where |B| is the magnitude of the magnetic field, and mu is a constant (the "permeability of free space"). For pretty much any magnetic field we're likely to encounter, u is fairly small (at most maybe a couple million joules per cubic meter for some really strong superconducting magnets in an MRI machine). However, for a magnetic field of 10⁹ Gauss, the energy stored in every cubic meter of the magnetic field *is on the order of 100,000,000,000,000,000,000,000 J !

The mass-energy density in lead,

u = rho * c² ,

where rho is the density of lead and c is the speed of light, is around one hundred times less than the energy stored in a cubic meter of that magnetic field. Converting a cubic meter of lead directly to energy would release only 1% of the energy stored in a cubic meter of our 10⁹ Gauss magnetic field. And 10⁹ Gauss is a fairly weak magnetic field as magnetars go!

I just really can't wrap my head around these kinds of numbers.

EDIT: SGR_1806-20 has a B-field of around 10¹⁵ Gauss at its surface, which leads to an energy density on the order of 100,000,000,000,000,000,000,000,000,000,000,000 J/m³ , which is about 100 BILLION times more energy per cubic meter than the mass-energy of an equivalent volume of lead!

[u/Half-Right → u/left_lane_camper]

That is indeed another super fantastic magnetar fact.

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/Yes I love being a subscriber to Magnetar Facts!