Photo of the day: Celestial painting

This very impressive image was taken on top of the extinct Hawaiian volcano Mauna Kea. It is home to a number of telescopes, including the 8.1-meter Gemini North, which can be seen on the right side of the frame. During the shooting, the observatory was engaged in “celestial painting”, trying to penetrate the secrets of the Universe.

The starry sky over the top of Mount Mauna Kea. Source: International Gemini Observatory/NOIRLab/NSF/AURA/J. Chu

The characteristic red rays emitted by Gemini North and one of the telescopes in the background are lasers that create artificial stars. They are part of the adaptive optics system, which is an integral component of all modern observatories.

Adaptive optics technology works as follows. The laser highlights a layer of atomic sodium in the upper atmosphere, creating an artificial star. Then the computer compares the reference and real parameters of the artificial star. This allows it to calculate the characteristics of atmospheric turbulence and then compensate for them by changing the shape of the telescope’s secondary mirror. Thanks to this technology, which was first adopted by astronomers in the late 1980s, modern ground-based observatories can take pictures with a clarity not much inferior to the images of space telescopes.

Since the picture was taken with a long exposure, we can also see star tracks — traces left by stars in the process of their apparent movement around the celestial pole. This effect occurs due to the fact that the Earth rotates around its axis.

You can also admire the magnificent image of a group of distant galaxies, published in honor of the birthday of the Hubble telescope.

According to https://noirlab.edu

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