Messier 77

A giant group of stars is far away. It is called a galaxy. People call this one the Squid Galaxy. It looks like a swirl.

A long bar sits in its middle. This bar helps shape the galaxy. Thick dust hides the very center. A huge black hole lives there too.

This galaxy is very bright. It is part of a small group. Other small galaxies live near it. One galaxy looks twisted by it.

Scientists study this galaxy a lot. They see light and even tiny particles. It is a very special place in space.

Messier 77 is a large galaxy in the Cetus constellation. Some people call it the Squid Galaxy. Pierre Méchain found it in 1780. He first thought it was a nebula. Later, others thought it was a star cluster. Now we know it is a galaxy.

This is a barred spiral galaxy. It has arms that swirl around. A long bar sits in the middle. This bar is hard to see in normal light. We only see it using infrared light. Infrared light is a type of light we cannot see.

The center of the galaxy is very busy. It has an active galactic nucleus. This is a bright, active center. Thick dust hides this center from our eyes. A supermassive black hole lives behind the dust.

Messier 77 is part of a small group. It is the largest member of this group. Its gravity may have twisted a nearby galaxy. Scientists study it because it is very bright. They even found tiny particles called neutrinos coming from it.

Messier 77 is a huge galaxy in the Cetus constellation. Some people call it the Squid Galaxy. It is a barred spiral galaxy. This means it has arms that swirl around a central bar. The bar is hard to see in normal light. Scientists use infrared light to see it clearly. This galaxy is very bright and very important to study.

The center of this galaxy is very busy. It has an active galactic nucleus, or AGN. This is a bright and active center. Thick clouds of dust hide the center from our eyes. A supermassive black hole lives behind this dust. We can also see a radio jet in the galaxy. This jet moves through the space between stars. It creates shapes called bow shocks in the northeast region.

People have been looking at this object for a long time. Pierre Méchain discovered it in 1780. He first thought it was a nebula. He told his friend Charles Messier about it. Messier then put it in his famous catalog. Later, William Herschel thought it was a star cluster. Today, we know it is actually a galaxy.

Messier 77 is the largest part of a small galaxy group. This group includes the galaxy NGC 1055. The gravity of Messier 77 may have twisted NGC 1055. In November 2022, scientists found something special. They detected neutrinos coming from the center of the galaxy. Neutrinos are tiny particles. This was only the fourth time we found such a source.

Scientists use many tools to learn about this place. They use radio waves and infrared light to see through dust. They also use X-rays to study the bright center. In 2018, a supernova called SN 2018ivc happened here. A supernova is a huge star explosion. Studying Messier 77 helps us understand how active galaxies work. It is a prototype for many other galaxies like it.

Messier 77, also known as NGC 1068 or the Squid Galaxy, is a massive barred spiral galaxy. It is located within the constellation Cetus. This galaxy is highly significant because it is one of the brightest Seyfert galaxies visible from Earth. A Seyfert galaxy is a type of active galaxy with a very bright center. Messier 77 serves as a prototype for the Type 2 Seyfert class. This means it is a standard example that scientists use to understand how these energetic systems work.

The structure of Messier 77 is complex and involves several distinct parts. It is classified as a barred spiral galaxy. While some visual observations suggest it is a non-barred spiral, infrared images reveal a prominent bar in the center. This bar is hidden from view in visible light by thick astronomical dust. The galaxy also features an outer ring-like structure. Its spiral arms are described as being moderately wound. Some researchers have even suggested the arms are tightly wound.

At the heart of the galaxy lies an active galactic nucleus, or AGN. This is an extremely energetic central region. The AGN is obscured from our view by large amounts of astronomical dust. Scientists have used different tools to study this hidden area. For example, the VLBA and VLA measured the diameter of the molecular disk at radio wavelengths. The MIDI instrument at the VLTI later measured the hot dust surrounding the nucleus using mid-infrared light. These observations help us see what is happening behind the dust clouds.

Messier 77 is the largest member of a small group of galaxies. This group includes five small irregular galaxies. It also includes a spiral galaxy named NGC 1055. Scientists believe that gravitational interactions with Messier 77 may have twisted NGC 1055. This shows how the gravity of a large galaxy can change the shape of its neighbors. The galaxy also produces a radio jet. This jet has a northeast and a southwest region. The jet is caused by interactions with the interstellar medium, which is the matter between stars.

Humanity has been observing Messier 77 for many years. Pierre Méchain discovered the object in 1780. He originally described it as a nebula. He shared his discovery with Charles Messier, who added it to his famous catalog. Later, William Herschel described the object as a star cluster. Over time, our technology improved, and we realized it was actually a galaxy. In 2022, astronomers used infrared interferometry to find a cloud of cosmic dust at the center. This dust is hiding a supermassive black hole.

Recent scientific discoveries have provided even more detail about this galaxy. In November 2022, the IceCube collaboration detected neutrinos coming from the AGN. Neutrinos are tiny particles that are very difficult to catch. This was only the fourth known source of such neutrinos ever detected. One theory suggests these particles come from a magnetic corona around the nucleus. This area might accelerate particles to create neutron radiation. Another theory suggests helium nuclei collide with ultraviolet photons. This process breaks the nuclei apart and releases neutrons, which then decay into neutrinos.

Messier 77 also hosts spectacular individual events like supernovas. A supernova is the massive explosion of a star. One such event, named SN 2018ivc, was discovered on November 24, 2018. It was found by the DLT40 Survey and was classified as a Type II supernova. Studying these explosions helps scientists understand the life cycles of stars within active galaxies. By looking at the light and particles from Messier 77, we learn about the most powerful processes in our universe.