Cosmic Odd Couple

 

This image was taken by the Very Large Telescope (VLT) at ESO’s Paranal Observatory in Chile — the best place in the southern hemisphere for astronomical observing. But even without the help of telescopes like the VLT, a glance towards the southern constellation of Dorado (The Swordfish or Dolphinfish [1]) on a clear, dark night reveals a blurry patch which, at first sight, appears to be just like a cloud in the Earth’s atmosphere.

At least, this may have been explorer Ferdinand Magellan’s first impression during his famous voyage to the southern hemisphere in 1519. Although Magellan himself was killed in the Philippines before his return, his surviving crew announced the presence of this cloud and its smaller sibling when they returned to Europe, and these two small galaxies were later named in Magellan’s honour. However, they were undoubtedly seen by both earlier European explorers and observers in the southern hemisphere, although they were never reported.

The Large Magellanic Cloud (LMC) is actively producing new stars. Some of its star-forming regions can even be seen with the naked eye, for example, the famous Tarantula Nebula. However, there are other smaller — but no less intriguing — regions that telescopes can reveal in intricate detail. This new VLT image explores an oddly mismatched pair: NGC 2014 and NGC 2020.

The pink-tinged cloud on the right, NGC 2014, is a glowing cloud of mostly hydrogen gas. It contains a cluster of hot young stars. The energetic radiation from these new stars strips electrons from the atoms within the surrounding hydrogen gas, ionising it and producing a characteristic red glow.

In addition to this strong radiation, massive young stars also produce powerful stellar winds that eventually cause the gas around them to disperse and stream away. To the left of the main cluster, a single brilliant and very hot star [2] seems to have started this process, creating a cavity that appears encircled by a bubble-like structure called NGC 2020. The distinctive blueish colour of this rather mysterious object is again created by radiation from the hot star — this time by ionising oxygen instead of hydrogen.

The strikingly different colours of NGC 2014 and NGC 2020 are the result of both the different chemical makeup of the surrounding gas and the temperatures of the stars that are causing the clouds to glow. The distances between the stars and the respective gas clouds also play a role.

This pan video gives a close-up look at the two glowing gas clouds NGC 2014 and NGC 2020 in the Large Magellanic Cloud, in the southern constellation of Dorado (The Swordfish). NGC 2014 is irregularly shaped and red, while its neighbour, NGC 2020, is round and blue. These odd and very different gas clouds were both sculpted by powerful stellar winds from extremely hot newborn stars that also radiate into the gas, causing it to glow brightly. These observations were captured by ESO’s Very Large Telescope from Paranal Observatory in Chile.

This wide-field view captures an odd couple in the constellation of Dorado (The Swordfish): NGC 2014 and NGC 2020. These two glowing clouds of gas, in the centre of the frame, are located in the Large Magellanic Cloud, one of the Milky Way’s satellite galaxies. Both are sculpted by powerful winds from hot young stars.

This view was created from images forming part of the Digitized Sky Survey 2.