Telescope’s Laser Pointer Clarifies Blurry Skies

Although it is convenient for us humans (and all other forms of life on our planet for that matter), the atmosphere is almost everywhere cursed among astronomers. It's great for the breathing, but when it comes to astronomical observations of distant objects, the whole atmosphere tends to do is look to the muck. In the past 20 years, the development of adaptive optics - telescopes in essence, that change the shape of the mirror in order to improve their imaging skills - has improved dramatically, what we can in space from Earth to look.

With a new technology with lasers (laser Yes!!) Could the images in a position with an adaptive optics telescope nearly as crisp as those from the Hubble Space Telescope in a wide field of view. A team from the University of Arizona astronomer Michael Hart led a technique to calibrate the surface of the telescope is exactly what is very, very clear images of objects that would normally be very blurry help develop leads.

Laser adaptive optics in telescopes are a relatively new development in more and better image quality of ground-based telescopes. While it's nice to be able to use space telescopes like Hubble and the upcoming James Webb Space Telescope, they are certainly expensive to run and maintain. In addition, there are a lot of astronomers in the competition for very limited time for these telescopes. Telescopes like the Very Large Telescope in Chile and the Keck telescope in Hawaii, both already use lasers to improve adaptive optics for imaging.

Initially focused on the adaptive optics into a brighter stars in the vicinity of the area of ​​the sky that the telescope observing, and actuators in the back of the mirror were to raise very quickly moved from one computer atmospheric distortion. This system is limited to areas of the sky that contain such an object.

Laser adaptive optics are more flexible in its usability - the technique involves using a single laser to excite molecules to glow in the atmosphere, and then using this as a "beacon" to calibrate the mirror to distortions caused by turbulence in the atmosphere caused right. A computer analyzes the incoming light from the artificial guide star, and can determine how the atmosphere is behaving, to compensate for the change of the surface of the mirror.

When using a single laser, the adaptive optics to compensate for turbulence in a very limited field of vision. The new technique, pioneered at the 6.5-meter MMT telescope in Arizona used, not only a laser, green laser, but five to five separate guide stars in a wider field of view to produce 2 minutes of arc. The angular resolution is lower than those of the individual laser range - for comparison, the Keck and VLT images to produce a 30-60 milli-arcsec resolution, but it helps to see better across a wider field of view has many advantages.

The possibility that the spectra of old galaxies that are very weak, make it possible with this technique. By taking their spectra, scientists are better able to understand the composition and structure of objects in space. With the new technique, the spectra of galaxies, 10000000000 years old - and thus have a very high redshift - if possible from the ground.

Supermassive star clusters would also be easier to verify the technique, as images are captured in a single indication of the telescope on different nights, it would be understood by astronomers, the stars are part of the cluster and which are not gravitationally bound.