Cherenkov Telescope at Sunset
Image Credit &
Copyright:
Sarah Brands (University of Amsterdam)
Explanation:
On October 10, a new telescope reflected the light
of the setting Sun.
With dark horizon above and sunset colors below,
its segmented mirror inverts an image of the
beautiful evening sky in this snapshot
from the Roque del Los Muchachos Observatory on the
Canary Island of La Palma.
The mirror segments cover a 23 meter diameter and are mounted
in the open structure of the
Large Scale Telescope 1,
inaugurated as the first component of the
Cherenkov
Telescope Array (CTA).
Most ground-based telescopes
are hindered by the atmosphere that blurs, scatters, and absorbs light.
But cherenkov telescopes are designed to detect very high energy
gamma rays
and actually require the atmosphere to operate.
As the gamma rays impact the upper atmosphere they produce
air showers of high-energy particles.
A large, fast camera at the common focus images the brief flashes of
optical light, called
Cherenkov light,
created by the air shower particles.
The flashes reveal the incoming gamma ray timing, direction, and energy.
Ultimately more than 100 Cherenkov telescopes are planned for the CTA
at locations in both northern and southern hemispheres
on planet Earth.
Source: NASA