A long time ago in a galaxy far, far away…. Not just the star wars intro, but a true statement if you’re an astronomer. You see, once we start to look deep in space at the more distant objects in the universe, we are actually looking deep in time as well. It all begins with a light year. A light year is not a measure of time, it’s a measure of distance. When you turn on the light in a dark room, the light appears to fill the room instantly. But it actually takes a small amount of time, as light has...
Ever heard the term ‘champagne flow?’ I’m not talking about a celebration, it’s actually a term in astronomy. When a cluster of massive stars form and ionize the surrounding hydrogen cloud, the hot gas propels itself through the layers of cooler gas at the cluster outskirts. When the hot gas finally bursts through to the vacuum of space, it flows rapidly like a newly opened bottle of champagne. This is exactly what’s happening in the cluster RCW 34, a young, gaseous cluster in the southern constellation Vela. The interesting thing about this cluster is that its nearly invisible in optical...
One of the largest and brightest star clusters in the Milky Way galaxy is the Arches cluster, and its easy to see why. Lying only 100 light years away from the supermassive black hole that lies in the heart of our galaxy, it formed in an incredibly dense environment. It lies 25,000 light years from Earth in the constellation Sagittarius, and contains thousands of massive stars, including 160 that are hot, young, and exceptionally more massive than the Sun. Only 1 in 10 Million stars in the galaxy are as bright as these massive central 160 stars. Though it is...
When I do a planetarium show for an audience, and they see the night sky for the first time, I always ask them ‘What do you see?’ The response is the usual stuff – Stars, the Moon, maybe planets, or the Milky Way. But they seem to be missing the most important and largest part of the sky – the Darkness. Space itself. Stars light up the cosmos, but if there were no stars, would we think that the universe was empty? Perhaps, but if you can imagine this scenario, it gives you an important perspective when you want to...
Of the approximately 100 Million galaxies in the visible universe, we see incredible variation. We always try to classify them based on their shape, size, and peak radiation, but even then we still find others that stray from the usual patterns. In recent years, a new class of galaxies named Extremely Luminous Infrared Galaxies (ELIRGs) has been found with data from the Wide Field Infrared Survey (WISE). Now the king of the ELIRGs has been found, the most luminous galaxy in the universe. The galaxy, designated WISE J224607.57-052635.0, has a luminosity equal to 300 Trillion suns, and may owe its brightness...
It sounds like something out of a science fiction novel. The incredible and rare dark star cluster, hiding the evil super villain’s headquarters. A dark star cluster is something I would imagine as a spooky, eerie type of place where everything you see changes when you enter its space. Science fiction aside, a dark star cluster is real, and it’s a new type of cluster that is similar to the mighty dense globular clusters that orbit most galaxies. Globular clusters orbit in a halo of space around the centres of galaxies, and though our Milky Way harbours 150 of them,...
It has been well established that Galaxies have formed during the last 13.7 Billion years of cosmic evolution. They didn’t just pop into existence, but developed in a long and arduous process that spans immense time. Many of them will continue to flourish for many Billions of years. If Galaxies do indeed have a birth, as has been seen, it stands to reason that they should someday ‘die’ as well. But have we ever seen the death of a galaxy? Have we ever seen the end for a massive collective structure of stars? We have seen galaxies collide and merge...
The Andromeda Galaxy is the closest large spiral to our own Milky Way, and the only major Galaxy moving toward us. Turns out its on a direct collision course, but we still have 3.5 Billion years to prepare, so its not exactly pressing news. On the plus side, studying Andromeda allows us to infer properties of more distant galaxies, and it gives us a map of what our own Milky Way Galaxy may look like. Astronomers using the Hubble Space Telescope have discovered a giant halo of gas around Andromeda, and the Milky Way may have a similar one. By...
Massive star clusters can pop into existence in a matter of a few million years, a very short period of time on astronomical time scales. They consist of hundreds or thousands of massive, bright, hot stars that will live relatively short lives of a few hundred millions of years. Using the Atacama Large Millimeter/Submillimeter Array (ALMA), astronomers have discovered a vanishingly rare molecular cloud of highly dense gas, containing no stars. It is poised to become a massive star cluster, and we found it in its infancy. “We may be witnessing one of the most ancient and extreme modes of...
As we push the limits of our technology, we naturally will find the biggest, the brightest, the smallest, the most extreme, and of course the most distant objects in the universe. We are at the time in history where we are beginning to see the edges of our universe in unprecedented detail. Eventually will will stop finding the biggest, brightest, and most distant, after which point our technology will serve to improve our precision and allow us to peer within these unique objects. Astronomers have used this incredible technology to discover the most distant galaxy in the universe, forming only...
