The world was much different in 1990 when NASA astronauts removed the Hubble Space Telescope from Space Shuttle Discovery’s cargo bay and placed it into orbit. The Cold War was ending, there were only 5.3 billion humans, and the World Wide Web had just come online.
Continue reading “The Venerable Hubble Space Telescope Keeps Delivering”Not All Black Holes are Ravenous Gluttons
Some Supermassive Black Holes (SMBHs) consume vast quantities of gas and dust, triggering brilliant light shows that can outshine an entire galaxy. But others are much more sedate, emitting faint but steady light from their home in the heart of their galaxy.
Observations from the now-retired Spitzer Space Telescope help show why that is.
Continue reading “Not All Black Holes are Ravenous Gluttons”Galaxies Evolved Surprisingly Quickly in the Early Universe
Anyone familiar with astronomy will know that galaxies come in a fairly limited range of shapes, typically; spiral, elliptical, barred-spiral and irregular. The barred-spiral galaxy has been known to be a feature of the modern universe but a study from astronomers using the Hubble Space Telescope has recently challenged that view. Following on observations using the James Webb Space Telescope has found the bar feature in some spiral galaxies as early as 11 billion years ago suggesting galaxies evolved faster in the early Universe than previously expected.
Continue reading “Galaxies Evolved Surprisingly Quickly in the Early Universe”Black Holes Can Halt Star Formation in Massive Galaxies
It’s difficult to actually visualise a universe that is changing. Things tend to happen at snails pace albeit with the odd exception. Take the formation of galaxies growing in the early universe. Their immense gravitational field would suck in dust and gas from the local vicinity creating vast collections of stars. In the very centre of these young galaxies, supermassive blackholes would reside turning the galaxy into powerful quasars. A recent survey by the James Webb Space Telescope (JWST) reveals that black holes can create a powerful solar wind that can remove gas from galaxies faster than they can form into stars, shutting off the creation of new stars.
Continue reading “Black Holes Can Halt Star Formation in Massive Galaxies”The Milky Way’s Smallest, Faintest Satellite Galaxy Found
The Milky Way has many satellite galaxies, most notably the Large and Small Magellanic Clouds. They’re both visible to the naked eye from the southern hemisphere. Now astronomers have discovered another satellite that’s the smallest and dimmest one ever detected. It may also be one of the most dark matter-dominated galaxies ever found.
Continue reading “The Milky Way’s Smallest, Faintest Satellite Galaxy Found”Webb Watches the Most Distant Galactic Merger Ever Seen
Astronomers know that galaxies form through mergers. They’ve been happening since the earliest epochs of cosmic time. Using the Webb telescope (JWST) astronomers found a massive merger of young galaxies going on about a half million years after the Big Bang. It’s called Gz9p3, one of the earliest and most distant mergers ever witnessed.
Continue reading “Webb Watches the Most Distant Galactic Merger Ever Seen”Astronomers Find the Most Massive Supercluster to Date
The Earth’s place in space is a fairly familiar one with it orbiting an average star. The star – our Sun – orbits the centre of our Galaxy the Milky Way. From here onwards, the story is less well known. The Milky Way is part of a large structure called the Laniakea Supercluster which is 250 million light years across! That really is a whacking great area of space and it contains at least 100,000 galaxies. There are larger superclusters though like the newly discovered Einasto Supercluster which measures an incredible 360 million light years across and is home to 26 quadrillion stars!
Continue reading “Astronomers Find the Most Massive Supercluster to Date”Are Andromeda and the Milky Way Already Exchanging Stars?
I often drag out the amazing fact that the Andromeda Galaxy, that faint fuzzy blob just off the corner of the Square of Pegasus, is heading straight for us! Of course I continue to tell people it won’t happen for a few billion years yet but a recent study suggests that we are already seeing hypervelocity stars that have been ejected from Andromeda already. It is just possible that the two galaxies have already started to exchange stars long before they are expected to merge.
Continue reading “Are Andromeda and the Milky Way Already Exchanging Stars?”Black Holes Need Refreshing Cold Gas to Keep Growing
The Universe is filled with supermassive black holes. Almost every galaxy in the cosmos has one, and they are the most well-studied black holes by astronomers. But one thing we still don’t understand is just how they grew so massive so quickly. To answer that, astronomers have to identify lots of black holes in the early Universe, and since they are typically found in merging galaxies, that means astronomers have to identify early galaxies accurately. By hand. But thanks to the power of machine learning, that’s changing.
Continue reading “Black Holes Need Refreshing Cold Gas to Keep Growing”This Galaxy Was Already Dead When the Universe Was Only 700 Million Years Old
When a galaxy runs out of gas and dust, the process of star birth stops. That takes billions of years. But, there’s a galaxy out there that was already dead when the Universe was only 700 million years old. What happened to it?
Continue reading “This Galaxy Was Already Dead When the Universe Was Only 700 Million Years Old”