* Astronomy

Blobrana · L

RE: Lucky Imaging

Blobrana · L

AstraLux

Blobrana · L

RE: Lucky Imaging

Blobrana · L

British astronomers from the University of Cambridge and the California Institute of Technology (Caltech) have developed a new camera using e2v's L3Vision imaging sensors that gives much more detailed pictures of stars and nebula than even the Hubble Space Telescope, and it does all this from the ground.

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Blobrana · L

A team of astronomers from the US and the UK has obtained some of the clearest pictures of space ever taken.
They were acquired using a new "adaptive optics" system which sharpens pictures taken from the Mount Palomar Observatory in California.
The images are twice as sharp as those from Hubble Space Telescope.
The new system, dubbed "Lucky", is the result of work by a team from Cambridge University and the California Institute of Technology (Caltech).

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Blobrana · L

AstraLux, a new, simple instrument developed at the Max Planck Institute for Astronomy in Heidelberg, has demonstrated at Calar Alto its ability to register extremely sharp astronomical images, comparable in resolution to views obtained with the Hubble Space Telescope. The new camera circumvents the unwanted optical blurring effects of the Earth's atmosphere. Using a high-speed camera, AstraLux records the brief instants in time in which the image of an astronomical object is least affected by the turbulence of the air. This results in a much sharper image with dramatically reduced blurring. Astronomers call this procedure "Lucky Imaging". Lucky, because only those fortunate moments with the best atmospheric conditions are selected for the final image.

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Blobrana · L

A remarkable new low-cost camera technique is helping UK astronomers find new stars.

A Cambridge team has overcome the problem of turbulence in the atmosphere which makes stars twinkle and hard to see by using a technique known as Lucky Imaging.
Millions of photographs are taken very quickly of a star in the hope that just a few are not blurred.
It turns out that a few pictures are as sharp as those captured by the Hubble Space Telescope.
Cash strapped amateurs have long used this process.

Two pictures are shown of the same region of a globular star cluster M15, taken on the same telescope within a few minutes of one another. The first was taken with a conventional high-quality scientific CCD camera while the second was taken with a high-speed CCD camera with the best 10% of images selected and combined to produce the image shown.

Now Lucky Imaging is being used on the world's most sophisticated telescopes.
Active and Adaptive Optics, which uses a complicated system of mirrors and computers to get detailed pictures, also counters the problem of atmospheric turbulence, but the system cost millions of pounds.
But Lucky Imaging used by the Institute of Astronomy project on the Nordic Optical Telescope in the Canary Islands has so far cost just £20,000.
The Nordic Optical Telescope has a diameter of 2.56m, and incorporates the new component that lets the camera run faster and more quietly. So far, the Cambridge team has observed 48 stars, and found that of them were actually double, or binary stars.

The scientists were looking for low-mass binary stars in particular, with an aim is to double the number of known very low-mass binary star systems.
Such stars were born at the same time, and the group used the fact that they orbit each other to measure how heavy they are. Often, the fainter a star is, the lower its mass.

"The mass of a star is the fundamental parameter that governs the life of a star. If a star is heavy, it lives very fast; it's a James Dean. It lives fast, dies young, and burns bright. If a star is very low mass, it just glows faintly and dimly for the lifetime of the Universe" - Dr Hodgkin.

The Cambridge researchers hope eventually to be able to calculate singles stars' masses by their brightness, by comparing them with binary stars.

"There's a lot of work being done on (future) extremely large telescopes, with a 30-100m diameter - Adaptive Optics is crucial to their operation. Lucky Imaging works best on moderate-sized telescopes in the visible and near infrared. The only dispute is how far can you push this technique?" - Professor Chris Dainty, National University of Ireland, Adaptive Optics specialist.

However, he said the technique would not replace the more advanced technologies.

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