Missing Lithium


The globular star cluster Messier 54Most of the light chemical element lithium now present in the Universe was produced along with hydrogen and helium during the Big Bang but in much smaller quantities. Astronomers have calculated how much lithium they expect to find in the early Universe and from this work out how much they should see in old stars. But the calculations don’t match the observed values. There is about one-third of lithium in stars that we expect to see in our galaxy, The Milky Way.

This new image from the VLT Survey Telescope at ESO’s Paranal Observatory the globular cluster Messier 54, a star cluster that doesn’t belong to the Milky Way but is part of a small satellite galaxy, the Sagittarius Dwarf Galaxy. A team of astronomers has used the VLT to measure how much lithium there is in a selection of stars in Messier 54. They find that the levels are close to those in the Milky Way. So, whatever it is that got rid of the lithium seems not to be specific to the Milky Way.

Image Credit: ESO

Visible and Invisible


Cat's PawThis comparison of infrared and visible views of the Cat’s Paw Nebula uses images taken by two of the telescopes belonging to the European Southern Observatory. The visible light image (right) was taken with the Wide Field Imager on the 2.2-m MPG/ESO telescope at La Silla in Chile. The new infrared image (left) was taken with the VISTA telescope at ESO’s Paranal Observatory. In the infrared, the dust that hides many stars is almost transparent, allowing many more stars to be seen.

Image Credit: ESO / J. Emerson / VISTA
Acknowledgment: Cambridge Astronomical Survey Unit

Looking at an Exoplanet


The SPHERE instrument on the Very Large Telescope at the European Southern Observatory has captured a series of images showing the passage of the exoplanet Beta Pictoris b around its parent star. SPHERE observed Beta Pictoris b directly, seeing it emerge from its passage in front of its parent star. The planet orbits its star at about the same distance as between the Sun and Saturn, approximately 1.3 billion km, making it the most closely orbiting exoplanet ever to have been directly imaged. In spite of the distance from its star, planet is still hot, around 1500 C.

Image Credit: ESO