The unusual nebula, too much like an eye staring at us from deep space, was the result of the demise of an unequal binary system of stars – and a couple of lucky coincidences.
In 2004, NASA’s Galaxy Evolution Explorer a space telescope discovered a very strange object. The vast cloud of gas with a bright star in the center is almost invisible in the optical range, but in ultraviolet waves it looks like a giant eye staring at us from the distant depths of the Galaxy. Since then, astronomers have been looking for an explanation for the origin of the unusual nebula ,called the Blue Ring, but the answer seems to have been received only now.
Observations of the nebula in recent years have shown that the cloud and the central star are surrounded by a shock wave ring, indicating the explosive nature of the process that gave rise to this structure. The origin of the cloud itself is unclear. At the same time, the star TYC 2597-735-1 turned out to be very old, thermonuclear reactions of hydrogen in its interior have already ended; in spite of this, there is an accretion disk of matter falling on the surface around it – as is typical for young stars.
All these paradoxes have only now been resolved, as reported in an article by Keri Hoadley and colleagues at the California Institute of Technology, published in the journal Nature. Apparently, the Blue Ring Nebula was formed by the remnants of a merger of two stars that occurred five thousand years earlier. As a rule, such objects quickly disappear from view behind dense clouds of gas, but the unique features of this nebula allow you to see even the central star.
Apparently, before it was an unequal binary system, its large star had a mass near the solar one, and the smaller one ten times less (about 100 Jupiter masses). As it approached death, a large star evolved into a red giant, approaching its neighbor. As a result, it “left orbit” and began to approach it in a spiral, losing the substance that formed the accretion disk.
As a result, the smaller star fell onto the larger one, ejecting a cloud of hot gas. Scattering, this cloud collided with the matter of the accretion disk and split in two. Thus, two expanding cones of the nebula were formed. By a rare coincidence, we see it almost exactly “full face”: one of the cones is directed almost exactly towards the Sun. Therefore, for observers from Earth, they overlap, and their ring structures form something like an eye.
Subsequently, the gas cloud cooled down. Today it slowly dissipates, and when interacting with particles of the interstellar medium, it emits weakly in the ultraviolet. We are in the right direction at the right time, while the Blue Ring Nebula looks like a strange eye: in a few thousand years it will disappear completely. In the meantime, we can observe it in all its glory – like the famous Homunculus nebula near Eta Carinae.