ESO’s Very Large Telescope (VLT) has achieved first light with a new adaptive optics mode called laser tomography — and has captured remarkably sharp test images of the planet Neptune, star clusters and other objects.
The pioneering MUSE instrument in Narrow-Field Mode, working with the GALACSI adaptive optics module, can now use this new technique to correct for turbulence at different altitudes in the atmosphere. It is now possible to capture images from the ground at visible wavelengths that are sharper than those from the NASA/ESA Hubble Space Telescope. The combination of exquisite image sharpness and the spectroscopic capabilities of MUSE will enable astronomers to study the properties of astronomical objects in much greater detail than was possible before.
The MUSE (Multi Unit Spectroscopic Explorer) instrument on ESO’s Very Large Telescope (VLT) works with an adaptive optics unit called GALACSI. This makes use of the Laser Guide Star Facility, 4LGSF, a subsystem of the Adaptive Optics Facility (AOF). The AOF provides adaptive optics for instruments on the VLTs Unit Telescope 4 (UT4). MUSE was the first instrument to benefit from this new facility and it now has two adaptive optics modes — the Wide Field Mode and the Narrow Field Mode .
The MUSE Wide Field Mode coupled to GALACSI in ground-layer mode corrects for the effects of atmospheric turbulence up to one kilometre above the telescope over a comparatively wide field of view. But the new Narrow Field Mode using laser tomography corrects for almost all of the atmospheric turbulence above the telescope to create much sharper images, but over a smaller region of the sky .
With this new capability, the 8-metre UT4 reaches the theoretical limit of image sharpness and is no longer limited by atmospheric blur. This is extremely difficult to attain in the visible and gives images comparable in sharpness to those from the NASA/ESA Hubble Space Telescope. It will enable astronomers to study in unprecedented detail fascinating objects such as supermassive black holes at the centres of distant galaxies, jets from young stars, globular clusters, supernovae, planets and their satellites in the Solar System and much more.
Adaptive optics is a technique to compensate for the blurring effect of the Earth’s atmosphere, also known as astronomical seeing, which is a big problem faced by all ground-based telescopes. The same turbulence in the atmosphere that causes stars to twinkle to the naked eye results in blurred images of the Universe for large telescopes. Light from stars and galaxies becomes distorted as it passes through our atmosphere, and astronomers must use clever technology to improve image quality artificially.
To achieve this four brilliant lasers are fixed to UT4 that project columns of intense orange light 30 centimetres in diameter into the sky, stimulating sodium atoms high in the atmosphere and creating artificial Laser Guide Stars. Adaptive optics systems use the light from these “stars” to determine the turbulence in the atmosphere and calculate corrections one thousand times per second, commanding the thin, deformable secondary mirror of UT4 to constantly alter its shape, correcting for the distorted light.
MUSE is not the only instrument to benefit from the Adaptive Optics Facility. Another adaptive optics system, GRAAL, is already in use with the infrared camera HAWK-I. This will be followed in a few years by the powerful new instrument ERIS. Together these major developments in adaptive optics are enhancing the already powerful fleet of ESO telescopes, bringing the Universe into focus.
This new mode also constitutes a major step forward for the ESO’s Extremely Large Telescope, which will need Laser Tomography to reach its science goals. These results on UT4 with the AOF will help to bring ELT’s engineers and scientists closer to implementing similar adaptive optics technology on the 39-metre giant.
Learn more: Supersharp Images from New VLT Adaptive Optics
Check this out: 2019 Astronomer’s Guide to the Night Sky
The Latest on: Very Large Telescope
via Google News
The Latest on: Very Large Telescope
- Telescope confirms asteroid not a threaton August 13, 2019 at 3:05 am
The European Southern Observatory’s Very Large Telescope in Chile ruled out such a collision last month when it scanned the skies where the asteroid would appear if it were to strike the Earth in ...
- Telescope array discovers a trove of ancient, massive galaxieson August 11, 2019 at 10:09 am
Even so, it took further data from the imaginatively named Very Large Telescope in Chile to really prove we were seeing ancient massive galaxies where none had been seen before.” “This is the first ...
- Lego Extremely Large Telescopeon August 1, 2019 at 3:41 pm
It’s expected to enable research that would now be much too difficult with the current telescopes. The ELT’s surface area will be roughly five times as large as the Very Large Telescope, and it can ...
- WHAT IS THE VERY LARGE TELESCOPE?on July 27, 2019 at 5:00 pm
The European Southern observatory (ESO) built the most powerful telescope ever made in the Atacama Desert of northern Chile. It is called the Very Large Telescope (VLT) and is widely regarded as one ...
- Telescope’s Optic Upgrade Produces Super Sharp Imageson July 26, 2019 at 5:00 pm
The European Southern Observatory’s latest telescope technology works like a pair of contacts to make cosmic images clearer. A new adaptive-optics module on ESO’s Very Large Telescope in Chile means ...
- No telescope neededon July 26, 2019 at 7:21 am
This striking image was taken from the Paranal Observatory in Chile without having to use any of its arsenal of telescopes – which include the Very Large Telescope (VLT) and four Auxiliary ...
- Very Large Telescope findings could force physicists to rethink the Big Bangon July 25, 2019 at 5:00 pm
Humans are naturally predisposed toward exceptionalism and the idea that, by some divine inherited right, we are distinct from the rest of the universe. This may actually be true if we are the only ...
- The Very Large Telescope captures the beautiful remnants of a dying staron July 14, 2019 at 10:32 am
This red-hued cloud of gas is named Abell 24, and is located in the constellation of Canis Minor (The Lesser Dog). The image was taken with the VLT’s FORS (FOcal Reducer and Spectrograph) instrument.
- Very Large Telescope Gears Up to Hunt Exoplanets in Alpha Centaurion June 18, 2019 at 4:02 am
Astronomers around the world were thrilled in 2016 when the European Southern Observatory announced the discovery of an exoplanet around Proxima Centauri, the closest star to Earth. The Centauri ...
via Bing News