Starship Asterisk*

This image shows the Vela pulsar wind nebula. Light blue represents X-ray polarization data from NASA’s Imaging X-ray Polarimetry Explorer. Pink and purple correspond to data from NASA’s Chandra X-Ray observatory, which has observed Vela several times previously. NASA’s Hubble Space Telescope contributed the stars in the background.

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Credits: X-ray: (IXPE) NASA/MSFC/Fei Xie & (Chandra) NASA/CXC/SAO;
Optical: NASA/STScI Hubble/Chandra processing by Judy Schmidt;
Processing & Compositing: NASA/CXC/SAO/Kimberly Arcand & Nancy Wolk

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About 10,000 years ago, light from the explosion of a giant star in the constellation Vela arrived at Earth. This supernova left behind a dense object called a pulsar, which appears to brighten regularly as it spins, like a cosmic lighthouse. From the surface of this pulsar, winds of particles emerge that travel near the speed of light, creating a chaotic hodgepodge of charged particles and magnetic fields that crash into surrounding gas. This phenomenon is called a pulsar wind nebula.

In this new image, the hazy light blue halo corresponds to the first-ever X-ray polarization data for Vela, which comes from NASA’s Imaging X-ray Polarimetry Explorer, or IXPE. A faint blue fuzzy line pointing to the upper right-hand corner corresponds to a jet of high-energy particles shooting out from the pulsar at about half the speed of light. The pink X-ray "arcs" are thought to mark the edges of donut-shaped regions where the pulsar wind shocks and accelerates high-energy particles. The pulsar itself is located at the white circle at the center of the image. ...

Measuring polarization, which has to do with how electromagnetic waves are organized, gives scientists an unprecedented understanding of how a cosmic object like a pulsar accelerates particles to high speeds. ... In a recent study, scientists were surprised about the high degree of polarization they found in the X-rays at the Vela pulsar wind nebula. ...

High polarization means that the electromagnetic fields are well organized; they are lined up in specific directions, and depend on their position in the nebula. What’s more, the X-rays that IXPE detects come from high-energy electrons spiraling in the magnetic fields of the pulsar wind nebula, called “synchrotron emission.” Highly polarized X-rays means that these magnetic fields, too, must be well organized. ...

• Nature 612(7941):658 (22 Dec 2022) DOI: 10.1038/s41586-022-05476-5