This Picture of the Week shows Gum 46, a stunning gas cloud 5500 light-years away, observed in brand new detail with ESO’s Very Large Telescope (VLT). But why does it glow pink?

At the heart of Gum 46 there’s a young, hot and blue star called HD311999. Its intense radiation excites atoms in the surrounding gas, which then re-emit this energy at very specific colours or wavelengths. The pink shade that dominates this image is due to hydrogen atoms, the most abundant element in this nebula and the Universe as a whole.

The dark wispy clouds that surround the nebula make for a stunning sight too. These clouds are not intrinsically dark: they are extremely dense regions of dust that block light passing through them, enshrouding the glowing heart of Gum 46.

This image was created as part of the ESO Cosmic Gems programme, an outreach initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.