The James Webb Space Telescope has revealed a stunning, never-before-seen view of the barred spiral galaxy Messier 77, also known as the Squid Galaxy. This galaxy, located about 62 million light-years away in the constellation of Cetus, is one of the brightest and best-studied galaxies in the night sky. At 100,000 light-years across, it's one of the largest galaxies in the Messier catalogue, and its gravity causes other nearby galaxies to twist and become warped.
What makes Messier 77 particularly fascinating is its active galactic nucleus (AGN). At the heart of this galaxy is a compact region filled with hot gas that outshines the rest of the galaxy, even overcoming the light-gathering capacity of Webb's cameras. This AGN is powered by a supermassive black hole, eight million times as massive as our Sun. The gas in the galaxy's central regions is pulled by strong gravity into a tight and rapid orbit around the black hole, where it crashes together and heats up, releasing tremendous amounts of radiation.
The James Webb Space Telescope's Mid-Infrared Instrument (MIRI) and Near-Infrared Camera (NIRCam) have captured stunning images of Messier 77, highlighting its swirling spiral arms, dust in its disk, and its brilliant core. The bright orange lines appearing to radiate out from the galaxy's center are actually diffraction spikes, a type of distortion that arises from the optical design of the telescope.
One of the most intriguing features of Messier 77 is its starburst ring, a bright ring formed by the inner ends of its two spiral arms. This ring is more than 6,000 light-years across and displays intense and widespread starbursts, visible in the image by the densely concentrated orange bubbles all around the ring. Since Messier 77 is relatively close to Earth, this starburst ring is a very well-studied example of the phenomenon.
The galaxy's disk is filled with gas and dust, which is both a product of and fuel for future star formation. Webb's MIRI fills out our view of the galaxy with the glow of interstellar dust grains emitted at longer wavelengths, shown here in blue. The dust forms a huge vortex of smoky, swirling filaments with cavities in between, and the glowing orange bubbles carved out by newly formed star clusters are also prominently visible out along the galaxy's arms.
Beyond Webb's focused view, Messier 77's arms join into a faint extended ring of hydrogen gas thousands of light-years wide, where yet more star formation is taking place. Vast, tenuous filaments of hydrogen gas stretch across this ring and out into intergalactic space, forming an outermost layer around the galaxy. For its tentacle-like appearance, Messier 77 is also named the Squid Galaxy.
In my opinion, the James Webb Space Telescope's images of Messier 77 are a testament to the power of modern technology and our ongoing quest to understand the universe. These images not only reveal the beauty and complexity of galaxies but also provide valuable insights into the processes that shape them. As we continue to explore the cosmos, I believe we will uncover even more fascinating secrets about the universe and our place within it.
