Gamma rays are the most powerful form of electromagnetic radiation in the universe. With wavelengths as small at atoms, they usually result from the most powerful interactions known, such as the collision of two particles, or the release of energy from the accretion disk of a black hole. But there is another potential source of gamma rays that has not yet been confirmed: Dark Matter. The leading candidate for dark matter is the theorized Weakly Interacting Massive Particle (WIMP), though it is not as wimpy as its namesake suggests, making up 5 times as much mass as the visible matter...
A few days ago I wrote about a galaxy that was tough to see because of Milky Way field stars. But our galaxy is far more than just a bunch of stars smattered about. There is also a huge amount of gas and dust with varying temperatures. Some of the hotter and more illuminated gas and dust are what make nebulae so lovely in space. But the cold gas and dark dust that is just out floating in the cold interstellar medium? That stuff gets in the way. A normal image of interacting galaxies M81 and M82 would try to hide the...
Welcome to a new series of posts that will characterize 1000 amazing facts about the Universe. There is so much out there that we have yet to learn, and every day, astronomers across the globe are using their research to reveal the deepest secrets of the cosmos. This series will look at the strangest, coolest, most exciting facts that we have discovered in hundreds of years of modern science. Fact #4: Most of the stars in the universe are red dwarfs smaller than our Sun. There is a leap of understanding that happens when a child learns that our Sun...
Remember the big picture of Andromeda that showed 100 Million stars? That image resulted in a ton of new galaxy discoveries. Most of these new galaxies were once hidden beyond the Andromeda galaxy, but with the super high resolution image, astronomers and the public were able to look straight through and see far more distant objects. Most images of galaxies have what we call ‘field stars’ in them. These are some of the 400 Billion stars of the Milky Way that are far closer than the galaxy we are imaging. For this reason, galaxy images tend to look very cluttered...
There are many types of objects in space that just can’t be seen with visible light, and many more that have very different features when observed across the electromagnetic spectrum. A prime example of the former is a molecular cloud. Cold, incredibly huge, and full of low density Hydrogen, these clouds are the raw material for star forming galaxies. If stars begin to form within them, they can be seen as gorgeous nebulae, but when alone in the darkness of space we need to look for the dim signature of radio waves they emit. The Smith cloud, named after it’s...
The big dipper is visible every day of the year from the Northern Hemisphere. It’s easily recognizable and most people have spotted it at least once in their life. But most people also assume that it is just a boring collection of stars where nothing interesting ever happens. The big dipper is so much more than a simple spoon in the sky, especially right now. The well-known asterism, part of the much larger Ursa Major constellation, is home to many visible deep-sky objects, though right now it is visited by the comet C/2013 US10 Catalina, close to the visible binary...
When you think of a nebula forming stars, it’s hard to imagine how large it is. Most nebulae form hundreds or even thousands of stars before being blown away by the young stellar winds. Pockets of a nebula collapse into dense regions that will eventually become stars with surrounding planetary systems. There are places in the galaxy we can look and actually see it happening. Pictured above, the beautiful ‘running chicken’ nebula, as strangely named as it is, is in the later stages of it’s star forming life. Many bright young stars have formed and their intense radiation is now...
We just saw it. Another record breaker. This incredible explosion of a massive dying star is the brightest supernova ever observed. You may think you get how big this explosion was, but it was brighter than collective brightness of all the 400 Billion stars in the Milky Way. You may be asking why you can’t see it in the sky. Well even though it is incredibly bright, it is 3.8 Billion light years away in a distant galaxy, so the discovery needed a huge telescope. It may have been powered by a rare star called a magnetar, a star with such an...
You may have heard about the leaked rumour about the discovery of gravitational waves from earlier this week. It was from Lawrence Krauss, who is an amazing science communicator and author, as well as a darn good astrophysicist. My earlier rumor about LIGO has been confirmed by independent sources. Stay tuned! Gravitational waves may have been discovered!! Exciting. — Lawrence M. Krauss (@LKrauss1) January 11, 2016 It’s safe to say that as a guy with an inside scoop on a lot of the latest science news, this is something to get excited about. The ‘LIGO’ he is referring to stands...
We know that galaxies like our Milky Way are far more massive than we can see. The dark matter in the Milky Way makes up 90% of it’s total mass. Another way of saying this is the Mass to Light ratio, comparing the total mass inferred by the rotation speed of the galaxy to the total mass of stars in the galaxy. This ratio, M/L, for the Milky Way, is about 10. But for a galaxy cluster, the M/L ratio is more like 100. Galaxy clusters are not just dense collections of stars and massive galaxies, they are also immense...
