Hubble provides a new view of a galactic favorite
As part of ESA/Hubble's 35th anniversary celebrations, the European Space Agency (ESA) is sharing a new image series revisiting stunning, previously released Hubble targets with the addition of the latest Hubble data and new processing techniques.
ESA/Hubble published a new image of NGC 346 as the first installment in the series. Now, they are revisiting a fan-favorite galaxy with new image processing techniques. The new image reveals finer detail in the galaxy's disk, as well as more background stars and galaxies.
Over the past two decades, Hubble has released several images of the Sombrero Galaxy, including this well-known Hubble image from October 2003. In November 2024, the NASA/ESA/CSA James Webb Space Telescope also provided an entirely new perspective on this striking galaxy.
Located around 30 million light-years away in the constellation Virgo, the Sombrero Galaxy is instantly recognizable. Viewed nearly edge on, the galaxy's softly luminous bulge and sharply outlined disk resemble the rounded crown and broad brim of the Mexican hat from which the galaxy gets its name.
Though packed with stars, the Sombrero Galaxy is surprisingly not a hotbed of star formation. Less than one solar mass of gas is converted into stars within the knotted, dusty disk of the galaxy each year. Even the galaxy's central supermassive black hole, which at nine billion solar masses is more than 2,000 times more massive than the Milky Way's central black hole, is fairly calm.
The galaxy is too faint to spot with the unaided eye, but it is readily viewable with a modest amateur telescope. Seen from Earth, the galaxy spans a distance equivalent to roughly one-third the diameter of the full moon. The galaxy's size on the sky is too large to fit within Hubble's narrow field of view, so this image is actually a mosaic of several images stitched together.
One of the things that makes this galaxy especially notable is its viewing angle, which is inclined just six degrees off of the galaxy's equator. From this vantage point, intricate clumps and strands of dust stand out against the brilliant white galactic nucleus and bulge, creating an effect not unlike Saturn and its rings—but on an epic galactic scale.
At the same time, this extreme angle makes it difficult to discern the structure of the Sombrero Galaxy. It's not clear whether it's a spiral galaxy, like our own Milky Way, or an elliptical galaxy. Curiously, the galaxy's disk seems like a fairly typical disk for a spiral galaxy, and its spheroidal bulge and halo seem fairly typical for an elliptical galaxy—but the combination of the two components resembles neither a spiral nor an elliptical galaxy.
Researchers used Hubble to investigate the Sombrero Galaxy, measuring the metals (what astronomers call elements heavier than helium) in stars in the galaxy's expansive halo. This type of measurement can help astronomers better understand a galaxy's history, potentially revealing whether it merged with other galaxies in the past.
In the case of the Sombrero Galaxy, extremely metal-rich stars in the halo point to a possible merger with a massive galaxy several billion years ago. An ancient galactic clash, hinted at by Hubble's sensitive measurements, could explain the Sombrero Galaxy's distinctive appearance.
Provided by NASA
