The Arc of Milky Way in the Twilight with the Moon and Zodiacal Light above VLT

| | | | | | | | | | |

The entire Arc of Milky Way full of gas and dust can be seen in this panoramic lovely view from the southern sky, captured in the end of nautical twilight, above the Very Large Telescope platform. At left of the small tower, above the horizon, the bright object visible is not a star itself, but the great globular cluster Omega Centauri. Closer to left in the beginning of Milky Way arc, are spotted the bright stars of Alpha and Beta Centauri. In the middle of the image, the strong light of crescent moon is shining above the Antu telescope, the first one. Above the moon, we can see the planet Saturn, the orange star Antares from Scorpius constellation, and the dark streaks that are part of Rho Ophiuchi cloud complex, which connects this region to the main arm of Milky Way with more then 200º from side to side. In the background of this same region, a faint white light is visible, called the Zodiacal Light. In the foreground at right, we can see the Yepun telescope, reflecting a silver color coming from the moon reflection on its metallic surface. In the extremely right edge of the image, the Andromeda galaxy is even visible as an elongated diffuse dot.

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 15/10/2015 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