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NASA Pictures The Hubble Space Telescope show the amazing Stingray Nebula fading at unprecedented speed.
The Stingray Nebula, officially known as Hen 3-1357, is the youngest known planetary nebula in our sky. However, Hubble images taken 20 years apart show a dramatic change in the nebula’s shape and brightness: Its once-rugged bright blue clouds of interstellar dust and gas have all but disappeared, according to a statement from the NASA.
“It’s very, very dramatic and very strange,” said Martín A. Guerrero, astronomer at the Instituto de Astrofísica de Andalucía in Spain and member of the team on the ongoing analysis, said in the statement. “What we are seeing is the evolution of a nebula in real time. Within a few years, we see variations in the nebula. We have never seen this before with the clarity that we have. let’s get with this view. “
Gallery: Strange shapes of nebulae, what do you see?
The recent study of the Stingray Nebula compares Hubble images taken in 1996 and 2016. Previous photos capture clouds of bright, blue, fluorescent hydrogen gas toward the center of the nebula. But images taken in 2016 show the gas is all but gone, making the nebula appear smaller and darker. The gas shells also lost their distinct wavy edges which earned the nebula its aquatic namesake.
“Changes in nebulae have been seen before, but what we have here are changes in the fundamental structure of the nebula, ”Bruce Balick, senior researcher on the project and astronomer at the University of Washington, Seattle, said in the release.
The Stingray Nebula is made up of gas and dust expelled from its central star, known as SAO 244567. Typically, the star would continue to heat the material by expanding outward, causing ionization and glow. gas and dust.
However, data from Hubble images revealed rapid changes in the light emitted by the glowing nitrogen, hydrogen and oxygen emitted by the dying star. Specifically, the researchers found that the star’s oxygen emission dropped by a factor of nearly 1,000 between 1996 and 2016, the statement said.
“In most studies, the nebula usually gets larger. Here it fundamentally changes shape and weakens, and on an unprecedented timescale,” Balick said. “Plus, to our surprise, it doesn’t get bigger. Indeed, the once-shiny inner elliptical ring seems to shrink as it fades.”
When Hubble first photographed the Stingray Nebula in 1996, researchers believed the image represented the later life stages of SAO 244567, as the swelling cloud of glowing gas was projected by the dying star.
Now, however, it appears that SAO 245567 is going backwards in its stellar evolution, as more recent observations show that the Stingray Nebula has faded considerably and its brightest internal structure has contracted, instead of s’ continually expand. The rapid changes observed in the nebula’s luminosity and structure are believed to be triggered by the cooling of its central star. As the star cools, it emits less ultraviolet ionizing radiation which would otherwise heat the expelled gas and cause it to glow.
A previous study, led by Nicole Reindl of the University of Potsdam, showed that the temperature of SAO 245567 fell from less than 40,000 to 108,000 degrees Fahrenheit between 1971 and 2002. This temperature spike was probably caused by a brief explosion in helium at the heart of the star. , which would help explain why the Stingray Nebula appeared brighter in 1996, but has faded rapidly since, according to the release.
“We are very lucky to be watching him just then,” Reindl said in the new release. “During such a helium flash, it’s evolving very quickly, and that involves short evolutionary timescales, so we usually can’t see how these stars evolve. We were just there at the right time to get this.
A brief period of helium melting could have caused the star’s outer layers to swell and expel large amounts of gas and dust, creating the bright blue, fluorescent clouds of gas and dust seen in 1996. But in photos from 2016, the Stingray Nebula looks faded because the the star is cooling now.
If the nebula continues to fade at the current rate, researchers estimate that the structure will be barely detectable in 20 or 30 years, according to the NASA statement.
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