The James Webb Space Telescope has captured a surprising new view of a long-studied galactic neighbor, the Sombrero galaxy, revealing a perspective that looks quite different from the wide-brimmed Mexican hat for which it was named.
Taken with the space observatory’s Mid-Infrared Instrument, or MIRI, the image showcases the galaxy’s smooth inner disk, rather than the glowing core that usually shines in visible light images taken with the Hubble Space Telescope. Webb’s view makes the “crown” of the sombrero invisible, changing the appearance of the galaxy to resemble a bull’s-eye. Meanwhile, distant galaxies glimmer in the background of the image.
The galaxy — also known as Messier 104, or M104 — is about 30 million light-years from Earth in the Virgo constellation. French astronomer and comet hunter Pierre Méchain discovered it in 1781. Méchain named the galactic find for his colleague Charles Messier, who famously cataloged star clusters and nebulae.
Webb’s sensitive instruments can detect celestial objects through varying wavelengths of infrared light, which is invisible to the human eye, to reveal previously unseen details of the universe.
The fine details of Messier 104 detected by MIRI also showcase the galaxy’s outer ring, revealing how dust — a crucial ingredient for celestial objects such as stars and planets — is structured and distributed throughout the galaxy.
Previously, when NASA’s now-retired Spitzer Space Telescope observed the Sombrero galaxy, the outer ring appeared smooth, but Webb’s new imagery reveals the complex, clumpy nature of the dusty ring, which could suggest the presence of a stellar nursery.
Webb’s new detections also enabled astronomers to spot carbon-containing molecules, such as polycyclic aromatic hydrocarbons, in the dust ring, which further suggests that the galaxy’s outer ring may be home to star-forming regions. But the Sombrero galaxy is quiet in terms of star formation compared with other galaxies such as Messier 82. Ten times as many stars are born in the latter galaxy than the estimated 100 billion stars that exist in the Milky Way.
Scientists estimate that the rings of the Sombrero galaxy produce less than one solar mass of stars each year, with one solar mass equaling the mass of our sun. In contrast, the Milky Way is responsible for creating about two solar masses a year, according to NASA.
The supermassive black hole at the center of the Sombrero galaxy is also less active than those at the center of other galaxies, slowly consuming material from Messier 104 and releasing a bright but small jet of radiation.
But the galaxy is full of 2,000 globular clusters, or groups of hundreds of thousands of old stars gravitationally held together, providing the perfect place for astronomers to conduct comparison studies of stars that are the same age but differ in mass and other aspects.
The Webb telescope, launched in December 2021, will begin its fourth year of observing the universe in July. Scientists across the globe have applied for observation time with the telescope to search for exoplanets and their atmospheres, stars and distant galaxies.
