A weird dead star may have a solid-like surface made of iron crystals

X-ray observations amusement that a distant magnetar whitethorn person a aboveground made of a unusual worldly determination betwixt a coagulated and a fluid alternatively of a gaseous 1 similar astir stars

Space 3 November 2022

By Leah Crane

A conception representation of a magnetar

Getty Images/iStockphoto

A unusual prima astir 13,000 airy years distant whitethorn person a coagulated surface, not a gaseous 1 similar astir stars. The star, called 4U 0142+61 but nicknamed simply 4U, is a magnetar – the dense, highly magnetised corpse of a elephantine prima that exploded successful a supernova – and researchers person ne'er seen 1 similar this before.

Roberto Turolla astatine the University of Padova successful Italy and his colleagues utilized a NASA outer called the Imaging X-ray Polarimetry Explorer (IXPE) to analyse X-rays from the magnetar. Specifically, they looked astatine the polarisation of the airy – the level successful which the airy waves oscillate arsenic they propagate done space. This depends heavy connected the mean done which the waves are propagating, arsenic good arsenic electromagnetic fields, truthful they were capable to usage it to characterise 4U’s aboveground and the country straight astir it.

They recovered 2 unusual properties that suggested the magnetar mightiness person a coagulated surface. The archetypal was that the polarisation of the airy was precise weak, whereas a state would person acted arsenic a filter and allowed mostly polarised airy through. The 2nd was a abrupt 90 grade power successful the polarisation angle, precisely what simulations foretell for X-rays travelling retired done a coagulated aboveground straight into a abstraction bare of everything but electromagnetic fields.

Because of the utmost gravity astatine the aboveground of the magnetar, this unusual ammunition is astir apt a benignant of worldly called a Bingham plastic, which is determination betwixt a coagulated and a fluid – mayonnaise and toothpaste are 2 communal examples. But alternatively of being made of thing we would commonly subordinate with fluids, it is astir apt made of unusual crystals of robust and different dense elements, their atoms stretched into cigar shapes by the powerful magnetic fields, says Turolla.

While this prima does look to person a surface, walking connected it is retired of the question due to the fact that the gravity astatine your feet would beryllium so overmuch stronger than the gravity astatine your head. “There is this immense quality successful the gravity, which would decidedly termination you due to the fact that it would spaghettify you. Then determination is each the radiation and the utmost heat,” says Turolla. “Even getting adjacent would beryllium precise dangerous.”

It is not yet wide whether we should expect coagulated surfaces similar this to beryllium communal successful magnetars. The researchers chose 4U due to the fact that this benignant of reflection requires a batch of airy and it is 1 of the brightest magnetars successful the sky, but the observations inactive took astir a month. To stitchery capable information to fig retired whether different magnetars’ surfaces are coagulated oregon gaseous, we whitethorn person to hold a while.

Journal reference: Science, DOI: 10.1126/science.add0080

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More connected these topics:

• stars
• electromagnetism