SGR A

A supermassive black hole located at the center of our Galaxy, the Milky Way - Sagittarius A*. It has a mass estimated at around 4.1 million times that of the Sun. It is one of the most significant black holes in cosmology, serving as a subject of intensive scientific research.

MASS

8.149×1036 kg

EVENT HORIZON

24mln km

TEMPERATURE

1×10-9 ≈-273°C

DENSITY

Unknown (huge)

01

OBSERVATION

Sagittarius A* (Sgr A*) is a supermassive black hole located at the center of the Milky Way galaxy, approximately 26,000 light-years away from Earth. It boasts a mass of about 4.1 million times that of the Sun, confined within a region smaller than our solar system. Despite its immense gravitational pull, Sgr A* is famously challenging to observe directly due to the surrounding dust and gas obscuring visible light. However, astronomers have been able to study its effects on nearby stars and gas clouds, revealing its presence through the motions of these celestial bodies. Sgr A* plays a fundamental role in galactic dynamics, influencing the orbits of stars and regulating the flow of matter within the galactic nucleus. Intensive research efforts continue to unveil the mysteries surrounding Sagittarius A*, probing its formation, accretion processes, and emission properties to deepen our understanding of black hole physics and the evolution of galaxies.

02

FORMATION

OF BLACK HOLES

Black holes are formed through the gravitational collapse of massive stars. When a massive star exhausts its nuclear fuel, it can no longer support itself against its own gravity, causing it to collapse inward. During this collapse, the star's outer layers are ejected into space in a violent explosion known as a supernova, while the core of the star implodes. If the core's mass is above a certain threshold (about three times the mass of the Sun), the collapse continues until it forms a singularity – a point of infinite density at the center of a black hole.

PROTOSTAR FORMATION

Within one of the smaller clumps, gravity causes material to accumulate at the center, forming a dense protostar—a precursor to a star.

MASSIVE STAR EVOLUTION

The protostar continues to accrete mass and evolves into a massive star, undergoing nuclear fusion in its core and radiating energy into space.

SUPERNOVA EXPLOSION

As the massive star reaches the end of its life cycle, it exhausts its nuclear fuel and undergoes a cataclysmic explosion known as a supernova, ejecting outer layers of material into space.

BLACK HOLE FORMATION

The core of the massive star collapses under its own gravity, forming a black hole—a region of spacetime from which no light or matter can escape, representing Sagittarius A*.

CLOUD FORMATION

A vast cloud of interstellar gas and dust begins to break apart into smaller clumps due to gravitational forces, setting the stage for star formation.

PROTOSTAR FORMATION

Within one of the smaller clumps, gravity causes material to accumulate at the center, forming a dense protostar—a precursor to a star.

MASSIVE STAR EVOLUTION

The protostar continues to accrete mass and evolves into a massive star, undergoing nuclear fusion in its core and radiating energy into space.

SUPERNOVA EXPLOSION

As the massive star reaches the end of its life cycle, it exhausts its nuclear fuel and undergoes a cataclysmic explosion known as a supernova, ejecting outer layers of material into space.

BLACK HOLE FORMATION

The core of the massive star collapses under its own gravity, forming a black hole—a region of spacetime from which no light or matter can escape, representing Sagittarius A*.

03

LOCATION

Sagittarius A* (Sgr A*) holds a unique position in the cosmos, nestled at the very heart of our Milky Way galaxy. Located approximately 26,000 light-years away from Earth, Sgr A* occupies the center of the Milky Way's spiral structure, enveloped by a dense cluster of stars and interstellar matter known as the galactic bulge. This celestial heavyweight resides within the constellation Sagittarius, hence its name, and is situated in a region of the sky known as the Sagittarius constellation, which lies in the direction of the galactic center. Despite its central location within the Milky Way, Sgr A* is notoriously challenging to observe directly due to extensive obscuration by intervening dust and gas clouds.

04

ACCRETION

Accretion processes around Sagittarius A* are complex, driven by the immense gravitational pull of the supermassive black hole. As surrounding material, including gas, dust, and stars, spirals inward, it forms a swirling accretion disk—a cosmic whirlpool where gravitational forces, friction, and compression intertwine. This disk emits radiation across various wavelengths, illuminating the space around the black hole. Some material is ejected as powerful jets, reshaping the galactic landscape. The event horizon of Sagittarius A* represents a boundary of no return, where gravity becomes so overwhelming that not even light can escape. Understanding these processes is crucial for unraveling black hole activity and advancing our comprehension of the cosmos.

Sagittarius A*