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"Twinkle, twinkle, little star" is a kind of twisted lullaby for astronomers, because the effect that enchants the occasional stargazer blurs the images taken by the most powerful telescopes.
Sometimes known as "astronomical vision", flicker or blur is caused by turbulence in the Earth 's atmosphere, blurring the view of a telescope. The astronomical vision explains why astronomers flock to the mountains that reach the atmosphere and why space telescopes are so valuable.
New photographs published by the European Southern Observatory show how severe the effect can be. reduce the problem. To compare the different levels of image quality proposed, the photographs all focus on Neptune. [Laser-Aided ‘Hawk’ Camera Snaps Spectacular New View of Star Cluster]
Thanks to a new adaptive optics module, the Vary Large Telescope in Chile has a much sharper view Neptune Credit: ESO / P. Weilbacher (AIP)
The images come from the very large telescope of the observatory in Chile, which sports a new adaptive optics module on one of its telescopes. Adaptive optics produces sharper images by offsetting interference from the atmosphere. To do this, the system follows a specific star to see how its light is scrambled by the atmosphere. Then, it adjusts the visualization system to reverse this blur effect, producing much less blurred images.
The Very Large Telescope's views of Neptune, with and without its new adaptive optics module, show how much the new system represents a significant improvement
Credit: ESO / P. Weilbacher (AIP) [19659006] But astronomers do not want to limit themselves to observing nearby objects that can be used for this compensation process. Thus, rather than relying on natural stars, some adaptive optics systems use lasers to create their own "stars".
The new Very Large Telescope system, called Galacsi, makes adaptive optics work in this way. "guide stars." The lasers shine in bright orange, each beam extending about one foot (30 centimeters).
The system observes how these lasers change due to atmospheric turbulence and signals the flexible mirror of the telescope to recalibrate exactly the right way to cancel the turbulence. This process is repeated approximately 1,000 times per second, depending on the installation.
The system eliminates the effect of more than half a mile (900 meters) of atmosphere immediately above the telescope – as it physically amplified the telescope overhead of the most active part of the atmosphere.
The new view of Neptune by the Very Large Telescope is comparable to that of the Hubble Space Telescope. (The two images do not match because they were not taken at the same time.)
Credit: ESO / P. Weilbacher (AIP) / NASA, ESA and MH Wong and J. Tollefson (UC Berkeley)
The system so effectively compensates for the atmosphere that the test images taken with the system are as sharp as the photographs of the Hubble Space Telescope – which does not have to deal with the phenomenon of all. Instead of displaying Neptune as a mere purplish blue blur, as did the telescope before it was upgraded, the new images show the colorful gas strips that make up Neptune's atmosphere.
The European Southern Observatory has made a push on adaptation The Adaptive Optics module not only serves to study the planets in our solar system – it can also produce sharper images of Stars beyond our galaxy, like globular cluster NGC 6388. “/>
The Adaptive Optics Module not only serves to study the planets in our solar system – it can also produce sharper images of the planet. Stars beyond our galaxy, like the globular cluster NGC 6388.
Kammann (LJMU) / ESO
The new systems are also used for the next major project of the organization, the # 1; Extremely Large Telescope, which will apply an adaptive optics system similar to a much larger telescope. This telescope is currently under construction; Scientists hope that it will begin to function in 2024.
Email Meghan Bartels at [email protected] or follow her @meghanbartels . Follow us on @Spacedotcom Facebook and Google+. Original article on Space.com
