Tour: X-ray Telescopes Reveal the "Bones" of a Ghostly Cosmic Hand

In 1895, Wilhelm Röntgen discovered X-rays and used them to image the bones in his wife's hand, kicking off a revolutionary diagnostic tool for medicine. Now two of NASA’s X-ray space telescopes have combined their imaging powers to unveil the magnetic field “bones” of a remarkable hand-like structure in space. Together, these telescopes reveal the behavior of a dead collapsed star that lives on through plumes of particles of energized matter.

The story begins around 1,500 years ago when a giant star ran out of nuclear fuel to burn. This led to the star collapsing onto itself and forming an incredibly dense object called a neutron star.

Rotating neutron stars with strong magnetic fields are called pulsars. With today’s telescopes, astronomers use them as laboratories for extreme physics, offering high-energy conditions that cannot be replicated on Earth. For example, young pulsars can create jets of matter and antimatter moving away from the poles of the pulsar, along with an intense wind, forming a “pulsar wind nebula”. These are ideal places to study certain questions in physics.

In 2001, NASA’s Chandra X-ray Observatory first observed the pulsar PSR B1509-58 and revealed that its pulsar wind nebula — known as MSH 15-52 — randomly resembles a human hand. The pulsar is located at the base of the “palm” of the nebula.

Now, NASA’s newest X-ray telescope, the Imaging X-ray Polarimetry Explorer (IXPE), has observed MSH 15-52 for about 17 days, the longest it has looked at any single object since it launched in December 2021.

The IXPE data gives astronomers the first map of the magnetic field in the hand. The charged particles producing the X-rays travel along the magnetic field, determining the basic shape of the nebula, like the bones do in a person’s hand.

These new data are revealing interesting aspects of this cosmic hand that researchers did not know before. By combining the data from these two telescopes, astronomers are learning more not only about MSH 15-52, but also other pulsar wind nebulae in general, with more discoveries yet to come.