For decades, theoretical models of galaxy evolution have predicted that the supermassive black hole lying at the heart of the Milky Way is surrounded by thousands of smaller black holes left behind by dying stars. […]

The second data release of the Gaia collaboration on 25 April resulted in this extremely detailed image of the sky, which contains nearly 1.7 billion stars. The data comprise information on the position of these stars […]

Although barely noticeable in this image of a massive galaxy cluster (left), which was taken with the Hubble Space Telescope, the small blue dot in the centre of the inset could be the farthest star […]

Several nebulae make up this image, three of which form the large Seagull Nebula in the top centre, while a fourth in the bottom right is known as the Duck Nebula or Thor’s Helmet. The […]

Both objects in this image are blue but very different in nature. On the right is the famous Pleiades, a cluster of extremely bright blue stars 400 light years away that can be seen relatively […]

Figure Many questions remain about what happened in the first billion years of the universe. At around 100 million years old, the universe was a dark place consisting of mostly neutral hydrogen without many objects emitting detectable […]

This small planetary nebula, NGC 7027, was first spotted in 1878, only 450 years after the nebula first started expanding. The name “planetary nebula” is a misnomer, however. It dates back to William Herschel, who classified […]

Gamma rays Since 2008, astronomers have been puzzled by a mysterious feature in the cosmic-ray energy spectrum. Data from the PAMELA satellite showed a significant increase in the ratio of positrons to electrons at energies above 10 GeV. […]

Picture of the month This image shows a nebula named after Edwin Hubble, recorded by the observatory that bears his name. Hubble’s Variable Nebula was discovered more than 200 years ago and later studied in detail by Hubble in […]

Large solar flare This image of the Sun shows a large solar flare (on the right side of the picture) coming from a giant active region called AR2673 just as the region is about to disappear behind the […]

Carina Nebula This image from the Chandra X-Ray Observatory shows the Carina Nebula in X-rays (low-energy shown in red and the highest energy X-rays in blue). The nebula lies at an estimated distance of 6500–10,000 light years, […]

Two spiral galaxies In this Hubble Space Telescope image, which was released as part of the telescope’s 27th anniversary this year, two very different looking spiral galaxies are visible. The closely neighbouring galaxies – NGC 4302 on the […]

SN 1987A Thirty years ago, a massive stellar explosion sent shock waves not only through space but also through the astronomical community. Detected on 23 February 1987 in the Large Magellanic Cloud – a satellite galaxy of […]

After 13 years as the Courier’s Astrowatch contributor, astronomer Marc Türler is moving to pastures new. We thank him for his numerous lively columns keeping readers up to date with the latest astro results.

Porpoise Galaxy The night sky holds many stunning views, and this is certainly one of them. This pair of galaxies called Arp 142 is better known as the Porpoise Galaxy, although it rather looks like a penguin […]