When comparing two objects in space, Stephenson 2-18 and Phoenix A, it’s important to understand that they belong to entirely different categories of astronomical bodies. Stephenson 2-18 is a massive star, while Phoenix A is a black hole with a supermassive black hole at its center. Despite these differences, both are considered to be among the largest in their respective categories, yet their sizes differ significantly in terms of scale and type.
In simple terms, Phoenix A is bigger. The size comparison between these two is measured differently because one is a star and the other is a supermassive black hole. Stephenson 2-18 is one of the biggest stars and has a radius of about 2,150 times that of the Sun. It’s a red supergiant 19,570 light years from Earth and though big it’s still a star. Phoenix A is 8.6 billion light-years from Earth and has a supermassive black hole at its center with a diameter of about 366 billion miles (600 billion km). This black hole is massive compared to Stephenson 2-18’s radius so Phoenix A is bigger overall in size.
To sum up, while Stephenson 2-18 is a massive and remarkable star, Phoenix A is a supermassive black hole that surpasses the size of the star by far. The scale of such a massive black hole makes Phoenix A bigger than Stephenson 2-18 in terms of both diameter and overall mass.
When comparing Stephenson 2-18 and Phoenix A, we take into account that Stephenson 2-18 is a Star, while Phoenix A is a black hole. Despite these differences, both stand out in their respective categories due to their enormous size and importance.
Overview of Stephenson 2-18
Stephenson 2-18 is one of the largest known stars, it is identified as a red supergiant. Its radius approximates about 2,150 times that of the Sun, making it extraordinarily massive by stellar standards. Situated about 19,570 light years away from Earth in the constellation Scutum, it belongs to the cluster of Stephenson 2 stars. This star is unique in terms of its size and the amount of light it radiates, though its scale is dwarfed by the larger cosmic structures such as galaxies.
Overview of Phoenix A
Phoenix A is located in the Phoenix Cluster and is one of the most distant galaxies from Earth at 8.6 billion light-years. Phoenix’s defining feature is a supermassive black hole located at its center, the most massive black hole ever found in the universe. It has a diameter of 366 billion miles, this cowards any star including Stephenson 2-18.
Stephenson 2-18 vs Phoenix A
| Aspect | Stephenson 2-18 | Phoenix A |
| Type of Object | Red Supergiant Star | Galaxy with a Supermassive Black Hole |
| Size | Radius is approximately 2,150 times the Sun | Central black hole diameter: 366 billion miles |
| Location | Constellation Scutum, 19,570 light-years away | Phoenix Cluster, 8.6 billion light-years away |
| Luminosity | Extremely bright, powered by nuclear fusion | Accretion disk emits intense X-rays and gamma radiation |
| Main Feature | Extreme size and light output | An immense black hole dominating the galaxy |
| Scale | Stellar (star-level scale) | Galactic (galaxy-level scale) |
Size
Stephenson 2-18 is one of the largest known stars. Its radius is approximately 2,150 times the radius of the Sun. Its huge size makes it stand out among red giants. On the other hand, Phoenix A’s defining feature is the supermassive black hole at its center. Measuring 366 billion kilometers (600 billion km) in diameter, this black hole alone far exceeds Stephenson’s 2-18, showing a huge difference in size between stars and galaxies.
Type of Object
Stephenson 2-18 is a red supergiant star, a late-stage stellar object known for its massive size and relatively short lifespan compared to smaller stars. In contrast, Phoenix A is a black hole, a massive system containing billions of stars, gas, and dust. At its core lies one of the largest known supermassive black holes. This fundamental difference in type shows how each object represents extremes in different astronomical categories.
Mass
Stephenson 2-18 is estimated to be 12 to 100 times more massive than the Sun. But it pales in comparison to the black hole at the center of Phoenix A. The mass of Phoenix A is estimated to have a mass of 100 billion solar masses, making it one extremely massive black in the whole universe. The black hole’s mass affects an entire galaxy, shaping its structure and dynamics, far exceeding the impact of a single star like Stephenson 2-18.
Luminosity
Stephenson 2-18 shines brightly due to the enormous energy it emits as a star, producing a large amount of light. In contrast, Phoenix A’s light comes primarily from activity around its supermassive black hole. The accretion of gas and dust generates enormous amounts of energy, But this light is concentrated near the galaxy’s core. Both materials have their own luminosity. But the light sources are very different. which reflects the unique nature.
Why are Stephenson 2-18 and Phoenix A important?
Stephenson 2-18 and Phoenix A are important because they show the diversity and size of the universe. Stephenson 2-18 is one of the largest stars. It helps scientists learn more about how giant stars live and die. By studying this we understand things like supernovae and how black holes or neutron stars form.
Phoenix A, with its giant black hole, shows how galaxies work and how black holes affect their surroundings. This black hole is one of the largest known and controls the structure and activity of the galaxy. It affects the formation of stars and the movement of matter because Phoenix A is very far away. Therefore, it helps us learn about the early universe and how galaxies formed long ago.
Both are unique in how different the universe can be. Stephenson 2-18 shows the extremes of stars, and Phoenix A highlights the power of galaxies and black holes. Together, they help us understand the universe better.