January 18, 2017

Fox and Swiss 1.2-metre Leonhard Euler Telescope at ESO’s La Silla Observatory

Fox and Swiss 1.2-metre Leonhard Euler Telescope at ESO’s La Silla Observatory

Perched precariously on the edge of the habitable world, life manages to cling on. On the outskirts of the hot, dry Atacama Desert, this hardy South American grey fox has just awoken, stretching leisurely. These foxes are generally active during the night, making the most of the drop in temperature that comes with a respite from the hot Chilean Sun.

In the background there are other signs of life. This white dome houses the Swiss 1.2-metre Leonhard Euler Telescope, which is protected from the harsh conditions by its outer shell. As the skies grow darker at ESO’s La Silla Observatory another famously nocturnal species, the astronomer, wakes up, stretches, and gets ready to scan the skies with buzzing and whirring technology.

Image Credit: ESO/M. Tewes
Explanation from: https://www.eso.org/public/images/potw1406a/

Spiral Galaxy NGC 3521

Spiral Galaxy NGC 3521

This picture of the nearby galaxy NGC 3521 was taken using the FORS1 instrument on ESO’s Very Large Telescope, at the Paranal Observatory in Chile. The large spiral galaxy lies in the constellation of Leo (The Lion), and is only 35 million light-years distant. This picture was created from exposures taken through three different filters that passed blue light, yellow/green light, and near-infrared light. These are shown in this picture as blue, green, and red, respectively.

Image Credit: ESO/O. Maliy
Explanation from: https://www.eso.org/public/images/eso1129a/

Globular Cluster Palomar 1

Globular Cluster Palomar 1

The NASA/ESA Hubble Space Telescope has captured a clear view of the unusual globular cluster Palomar 1, whose youthful beauty is a puzzle for astronomers. This faint and sparse object is very different from the more familiar brilliant and very rich globular clusters and had to wait until 1954 for its discovery by George Abell on photographs from the Palomar Schmidt telescope.

Globular clusters are tightly bound conglomerations of stars, which are found in the outer reaches of the Milky Way, in its so-called halo. They are amongst the oldest objects in a galaxy, containing very old stars and no gas, which means there is no possibility of newborn stars introducing some fresh blood into the cluster.

However, at 6.3 to 8 billion years old, Palomar 1 is a youngster in globular cluster terms — little more than half the age of most the other globulars in our Milky Way, which formed during our galaxy’s violent early history. However, astronomers suspect that globular youngsters, such as Palomar 1, formed in a more sedate manner. Possibly a gas cloud meandered around in the Milky Way’s halo until a trigger kick-started star formation. Another possibility is that the Milky Way captured the stellar group; perhaps it was adrift in the Universe before it was gravitationally attracted to our galaxy, or maybe it had a violent beginning after all and is the remnant of a dwarf galaxy that was devoured by the Milky Way.

Behind the sparsely populated Palomar 1 several background galaxies are seen and a few nearby bright foreground Milky Way stars are also visible. Together with Palomar 1 these objects make up an attractive “family portrait”.

This picture was created from images taken with the Wide Field Channel of the Advanced Camera for Surveys. Images through orange (F606W, coloured blue) and near-infrared (F814W, coloured red) filters were combined. The exposure times were 1965 s per filter and the field of view is 3.0 arcminutes across.

Image Credit: ESA/Hubble & NASA
Explanation from: https://www.spacetelescope.org/images/potw1104a/