The more scientists look in the depths of the Universe with their telescopes, the more they realize how fragile and tiny we all are. Astronomers estimate that there are over 100 billion galaxies out there, judging only by the observations made by the Hubble Space Telescope. Each of those galaxies should harbor billions of stars, and automatically many more chances for life to exist elsewhere besides on Earth.
But stars are far from being the most astonishing objects that exist in the Universe. The so-called Blue Ring Nebula discovered in 2004 by scientists from NASA’s Galaxy Evolution Explorer is leaving everyone speechless, and the space object is once again under the spotlight. The nebula features a large and faint sphere composed of gas that has a star at its center. Two thick rings are also surrounding the cosmic object, which is why it was called The Blue Ring Nebula. Behold the stunning structure:
Credit: NASA/JPL-Caltech/M. Seibert (Carnegie Institution for Science)/K. Hoadley (Caltech)/GALEX Team
Multiple Earth- and space-based telescopes were responsible for further studies of the nebula for the next 16 years since its discovery, but astronomers became even more astonished. They couldn’t explain how the peculiar space object formed, nor what are the properties of the central star.
The result of binary stars merging with each other?
Binary systems are pretty common at least in our Milky Way galaxy, meaning pairs of two stars orbiting each other. As time passes, stars naturally expand their volumes, and that will cause them to eventually collide with each other. A team of scientists examined the same possibility for the Blue Ring Nebula. Involved in the study was Guðmundur Stefánsson from Princeton University.
Keri Hoadley, who is a postdoctoral scientist at Caltech and also the lead author of the study, declared:
Indeed, the spectroscopic data coupled with theoretical modeling shows that the Blue Ring Nebula is consistent with the picture of a merging binary star system, suggesting that the inwards spiraling companion was likely a low-mass star.
Two different spectrographs mounted on large telescopes were used for the new scientific research: the HIRES optical spectrograph from the Keck Telescope on top of Maunakea in Hawaii, and also the near-infrared Habitable-zone Planet Finder from the Hobby-Eberly Telescope located at McDonald Observatory in Texas.
Guðmundur Stefánsson says:
The spectroscopic observations were key in allowing us to understand the object further, from which we see that the central star is inflated, and we see signatures of accretion likely from a surrounding disk of debris.
The study paper describing the new findings of the Blue Ring Nebula was published in the journal Nature.