APOD and General Astronomy Discussion Forum
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This panorama of the landscape around ESO’s Paranal Observatory, located in the Chilean Atacama Desert, was taken by ESO Photo Ambassador Petr Horálek.
Captured at dusk, it shows the moment just after sunset, when the the sky is painted in beautiful colours of yellow, orange, red, even blue-purple, and the reddish hues of the desert below are enhanced by the soft light. This time of day is known as twilight, but is also referred to as blue hour (named for the colour of the sky). The unique and ethereal quality of the light during blue hour has also earned it the nickname of “sweet light” amongst artists and photographers.
The planet Venus stands out against the pink of the sky in the very centre of the image, while the Very Large Telescope (VLT) rests atop the mountain on the right, Cerro Paranal. The Andromeda Galaxy is faintly visible to the right of the four giant 8.2-metre-diameter VLT Unit Telescopes, recognisable by its iconic oval shape. Andromeda is a Northern sky object, barely visible above the safety pointing limits of the telescopes at Paranal.
In this image the NASA/ESA Hubble Space Telescope has captured the smoking gun of a newborn star, the Herbig–Haro objects numbered 7 to 11 (HH 7–11). These five objects, visible in blue in the top centre of the image, lie within NGC 1333, a reflection nebula full of gas and dust found about a thousand light-years away from Earth.
Herbig-Haro objects like HH 7–11 are transient phenomena. Travelling away from the star that created them, at a speed of up to 250 000 kilometres per hour they disappear into nothingness within a few tens of thousands of years. The young star that is the source of HH 7-11 is called SVS 13 and all five objects are moving away from SVS 13 toward the upper left. The current distance between HH 7 and SVS 13 is about 20 000 times the distance between Earth and the Sun.
Herbig–Haro objects are formed when jets of ionised gas ejected by a young star collide with nearby clouds of gas and dust at high speeds. The Herbig-Haro objects visible in this image are no exception to this and were formed when the jets from the newborn star SVS 13 collided with the surrounding clouds. These collisions created the five brilliant clumps of light within the reflection nebula.
