The structures and star populations of massive galaxies appear to change as they age, but much about how these galaxies formed and evolved remains mysterious. Many of the oldest and most massive galaxies reside in clusters, enormous structures where numerous galaxies are found concentrated together. Galaxy clusters in the early universe are thought to be key to understanding the lifecycles of old galaxies, but to date astronomers have located only a handful of these rare, distant structures.
For the first time ever, scientists have direct confirmation that a Wolf-Rayet star - sitting 360 million light years away in the Bootes constellation - died in a violent explosion known as a Type IIb supernova.
Thanks to a constellation of three satellites, ESA's SWARM mission will track and measure the planet's magnetic forces from its core to its upper atmosphere. Five months after the launch, the satellites are beginning to gather data.
Astronomers have developed a model that estimates the effect that ingesting large amounts of the rocky material from which 'terrestrial' planets like Earth, Mars and Venus are made has on a star's chemical composition and has used the model to analyze a pair of twin stars which both have their own planets.
The splashdown of SpaceX's Dragon spacecraft on May 18 concludes the company's third contracted resupply mission to the International Space Station, assisting scientists who have investigations returning to Earth complete their analyses.
The dunes of Titan tell cosmic tales. A Cornell senior and researchers have narrowed theories on why the hydrocarbon dunes - think plastic - on Saturn's largest moon are oriented in an unexpected direction, a solar system eccentricity that has puzzled space scientists.
Jupiter's trademark Great Red Spot - a swirling storm feature larger than Earth - is shrinking. This downsizing, which is changing the shape of the spot from an oval into a circle, has been known about since the 1930s, but now these striking new Hubble Space Telescope images capture the spot at a smaller size than ever before.
Magnetars are the super-dense remnants of supernova explosions. They are the strongest magnets known in the Universe - millions of times more powerful than the strongest magnets on Earth. A team of astronomers now believe they've found the partner star of a magnetar for the first time. This discovery helps to explain how magnetars form and why this particular star didn't collapse into a black hole as astronomers would expect.