Water-building molecule in Helix Nebula

This image presents the Helix Nebula first at optical wavelengths, as seen by the Hubble Space Telescope, then by Herschel’s SPIRE instrument at wavelengths around 250 micrometres. A spectrum is shown for the region identified on the image, showing the clear signature of CO and OH⁺ emission in the clumpy outer regions of the planetary nebula.

The molecular ion OH⁺ is needed for the formation of water, and ESA’s Herschel space observatory is the first to detect it in planetary nebulas – the product of dying Sun-like stars.

Full story: New molecules around old stars