The black hole at the center of Messier 87 imaged in polarized light.

Astronomers have used the Event Horizon Telescope (EHT) to reveal a new view of the black hole at the center of the Messier 87 (M87) galaxy. The image shows how the black hole looks and polarized light and marks the first time astronomers have measured polarization so close to a black hole.

Polarization is a signature of magnetic fields and is vital in explaining how the M87 galaxy can launch energetic jets from its core. M87 is located 55 million light-years away from Earth. One project researcher says that we are now seeing the next crucial piece of evidence in understanding how magnetic fields behave around black holes and how activity in the region drives powerful jets that extend far beyond the galaxy.

Scientists call the work a significant milestone because the polarization of light carries information allowing researchers to better understand the physics behind the image of the first black hole shared in 2019. That first image of a black hole was also captured using the EHT collaboration. Since taking the first image of the black hole, the EHT Collaboration has been diving deeper into data on the supermassive black hole at the center of M87 collected in 2017.

The investigation has found that a significant fraction of the light around the black hole is polarized. Scientists on the project say that the polarized-light image required years of work due to the complex techniques involved in obtaining and analyzing data. Light is polarized when it goes through certain filters, such as the lenses of polarized sunglasses, or when emitted in hot regions of space where magnetic fields are present.

Viewing the region around the black hole and looking at how light originating from it is polarized allows astronomers to sharpen their view of the region around the black hole. Scientists on the project say that the newly published polarized images are vital to understanding how magnetic fields allow the black hole to consume matter and launch its powerful jets. Those bright jets of energy and matter emanating from the galaxy's core extend at least 5000 light-years from its center and is one of the galaxy's most energetic features.