The galaxy is 600 million light-years from Earth

The origin of Hoag, the galaxy with a special shape, has been a mystery of science for nearly 70 years.

NASA posted a new image of the Hoag galaxy taken by the Hubble space telescope and geophysicist Benoit Blanco, Live Science reported on December 3. Astronomer Arthur Hoag discovered this object in 1950. This is a rare ring galaxy with a diameter of about 100,000 light-years.

Picture 1 of The galaxy is 600 million light-years from Earth
The Hoag Galaxy is 600 million light-years from Earth.(Photo: NASA).

In the image, billions of blue stars form the perfect circle of light surrounding a smaller, denser sphere of red stars. In the dark space between the two rings, viewers can see another ring galaxy much further away from Earth than Hoag.

Until now, scientists still do not know the exact reason for Hoag's appearance. Ring galaxies account for less than 0.1% of all known galaxies. Therefore, their study faces many challenges.

Arthur Hoag once theorized that the ring shape is only an optical illusion caused by gravitational lensing. This phenomenon occurs when large bodies in space bend and amplify light. However, later studies with more advanced telescopes suggest that the hypothesis is incorrect.

According to another famous theory, Hoag was originally a disk galaxy. The collision with a neighboring galaxy created a gap and caused Hoag's gravity to change forever. If the collision occurred within the past 3 billion years, astronomers could observe traces left by the radio telescope. But so far, they have not found any such traces.

If there is a major collision in the center of the Hoag galaxy, it must have occurred so long ago that no evidence remains. Experts have only found very few ring galaxies, none of which are as symmetrical as Hoag. Therefore, the Hoag galaxy is still a mystery of space science.