Magellanic Clouds, Zodiacal Light and Gegenschein on a VLT Panorama

| | | | | | | | |

In the left side of this – almost 360º- panoramic view, we can see Canopus star and the Large (LMC) and Small (SMC) Magellanic Clouds. Above the horizon, in the beginning of Milky Way arc, are yet visible the bright stars Alpha and Beta Centauri. At the center, lie down the galactic arm with the Zodiacal Light as a background of Antu telescope. Next to the last telescope is clearly visible the elongated diffuse light coming from Andromeda galaxy. In the upper part of the image and opposite direction of Magellanic Clouds, is shining a Gegenschein, that is a faint brightening of the night sky in the region of the antisolar point. Like the zodiacal light, the Gegenschein is sunlight scattered by interplanetary dust. Most of this dust is orbiting the Sun in about the ecliptic plane. It is distinguished from zodiacal light by its high angle of reflection of the incident sunlight on the dust particles. Below right and near the horizon, the Pleiades (M45) star cluster is visible next the tower silhouette.

The Very Large Telescope (VLT) is a telescope operated by the ESO – European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. The VLT is the world’s most advanced optical instrument, consisting of four Unit Telescopes with main mirrors of 8.2m diameter, which are generally used separately but can be used together to achieve very high angular resolution. The four separate optical telescopes are known as Antu, Kueyen, Melipal and Yepun, which are all words for astronomical objects in the Mapuche language, with optical elements that can combine them into an astronomical interferometer (VLTI), which is used to resolve small objects. The interferometer is complemented by four movable Auxiliary Telescopes (ATs) of 1.8 m aperture. The 8.2m diameter Unit Telescopes can also be used individually. With one such telescope, images of celestial objects as faint as magnitude 30 can be obtained in a one-hour exposure. This corresponds to seeing objects that are four billion (four thousand million) times fainter than what can be seen with the unaided eye. The telescopes can work together, to form a giant ‘interferometer’, the ESO Very Large Telescope Interferometer, allowing astronomers to see details up to 25 times finer than with the individual telescopes. The light beams are combined in the VLTI using a complex system of mirrors in underground tunnels where the light paths must be kept equal to distances less than 1/1000 mm over a hundred metres. With this kind of precision the VLTI can reconstruct images with an angular resolution of milliarcseconds, equivalent to distinguishing the two headlights of a car at the distance of the Moon.

Image taken taken in 16/10/2015 from Cerro Paranal, Atacama desert, Chile.


Copyright 2023 © All rights reserved to the author Miguel Claro | The website content is primarily in english, and partially in portuguese: en | pt