Some 45 light years from Earth, the galaxy NGC 4051 was discovered in the constellation Ursa Major by John Herschel in 1788. It is part of a spiral-rich subset of the Virgo supercluster of galaxies that includes the Milky Way. Classified as a Seyfert galaxy, NGC 4051 hosts a supermassive black hole in its core with 1.7 million times the mass of the Sun. Multiple supernovae blasts have been observed in the galaxy over the past several decades, the first in 1983 and the most recent in 2010 when the core of a massive star that had already lost its outer layers of hydrogen and helium exploded in a type 1c supernova. Such explosions are sometimes referred to as stripped core-collapse supernovae. This beautifully rendered view of NGC 4051 was captured by the Hubble Space Telescope.
Due for launch in 2020, ESA’s Euclid satellite will set astronomers a huge challenge: to analyse 100,000 strong gravitational lenses. The gravitational deflection of light from distant astronomical sources by interposing massive galaxies can create multiple images of the source that are not just visually stunning, but are also valuable tools for probing our universe.
In a Hubble Space Telescope survey of 2,753 young, blue star clusters in the neighbouring Andromeda Galaxy (M31), astronomers have found that M31 and our own galaxy have a similar percentage of newborn stars based on mass. The intensive survey was a unique collaboration between astronomers and “citizen scientists,” volunteers who provided invaluable help in analysing the mountain of data from Hubble.
A team of international scientists, led by astronomers from Cardiff University, has shown for the first time that galaxies can change their structure over the course of their lifetime. The researchers have shown that a large proportion of galaxies have undergone a major ‘metamorphosis’ since they were initially formed after the Big Bang.