If you look up into the sky on a clear night, you would see thousands of stars. There are surely many more that you would need a telescope to see. But there are not stars everywhere. You can zoom in further and further with bigger and bigger telescopes, until eventually you find gaps where you simply don’t see stars. For a long time it was thought that the gaps were empty, until the Hubble telescope peered through the darkness by taking a 200 hour exposure of a supposedly empty patch of sky. What it revealed was a universe full of...
Massive stars and low-mass stars live different lives. They are born in different environments, fuse different elements during the course of their lives, release different amounts of radiation across the electromagnetic spectrum, die in different ways, and enrich interstellar space with different metals. We see stars at all stages of life in the galaxy, and their study allows us to piece together how stars form, and how the rarest ones are different. The image above shows two distinct clouds, both about 5,000 light years away in the constellation Cygnus, along the Galactic plane. The smaller bubble on the left, literally...
What do other planetary systems look like? We have seen some where massive Jupiter-sized worlds orbit closer to their star than Mercury does to the Sun, baking them with radiation. Others have had multiple rocky planets within the Earth’s orbit distance. Some have planets similar to Earth in a variety of locations. But what about far away from the star? We never expected to find gas giants like Uranus and Neptune in the far reaches of our solar system. Are there planetary systems where planets live even farther away? Maybe there are planets that live in the empty darkness between stars,...
The only reason we can see black holes in the universe is because some of them swallow up gas and dust. This heats up material that is spinning rapidly around the black hole as it falls in (called an accretion disk), and produces massive jets of material due to conservation of angular momentum that can be seen across the universe. The energy released in the jets and the energy given off in the accretion disk are proportional to how much gas and dust is being consumed by the black hole. More matter = more food = more energy released. But...
Dark matter is everywhere. There is way more of it in the universe than the matter we are made of and interact with. Yet for the sheer amount of it, we have no way of determining what exactly it is. It’s as if we didn’t know what air was, and even though we could see it and breathe it, we couldn’t measure it. The most tantalizing part about dark matter is that we can see the gravitational effect it has, and so we can determine how much of it there has to be. Some places in the universe have more dark matter than...
Time is a very slow thing when we talk about the universe. Stars can live for many Billions of years, and over human timescales they seem stagnant and unchanging. So it’s no surprise that when we look at distant galaxies, they don’t appear to change at all over the course of centuries. But appearances can be deceiving. Galaxies do change, more quickly than you would imagine. M87, pictured above, is a monstrous Galaxy of nearly 1 Trillion stars, more than twice as populous as the Milky Way. It looks like a big fuzzy star, and it quite regular in appearance...
A couple of weeks ago, using the Subaru Telescope, astronomers from the Carnegie Institution for Science discovered the newest dwarf planet of our solar system, which may end up claiming the title for most distant dwarf planet. The object, which isn’t even confirmed as a dwarf planet yet, is called V774104. It resides a distance of 2-3 times that of Pluto, around 9 Billion Km. It is expected to be a little less than half of Pluto’s size, and it may have a highly eccentric orbit, bringing it closer to the Sun over it’s multi-century trip around the solar system. “That’s...
A few hundred million years after the big bang, the first stars formed. We aren’t exactly sure how, but we do know that they contained Hydrogen, Helium, and a little bit of Lithium. These were the only elements in the entire universe at the time. Within these first stars, the fusion of heavier elements began. Oxygen, Nitrogen, Carbon, Iron, and all the other elements that make up everything we know formed Billions of years ago in these first stars and in their progenitors. It was a slow process to produce these elements and seed them throughout the cosmos, but over...
The Milky Way is a decently big Galaxy. At 100,000 light years across, it is a full size barred spiral galaxy and distinctly different from what we would call ‘dwarf galaxies.’ But there are much larger galaxies in the universe. Most reside near the centre of a massive galaxy cluster and are the result of Billions of years of mergers and collisions. But some appear large because of their incredibly powerful release of energy. A new Galaxy discovered in the early universe by a team of astronomers from the National Centre for Radio Astrophysics is an incredible 4 million light years...
Out of the over 2000 confirmed exoplanets, not one has been seen in the conventional sense, where we would see it’s surface, map out features and colours, and understand it’s atmosphere or surface from what we saw. Instead all the knowledge we have of exoplanets is based on the light we see. How big is the dip in the Kepler Telescope’s light curve? What absorption features do the reflected light of this planet show? This information is the result of careful analysis and brilliant inference, since the planets themselves are immeasurably tiny and hard to spot next to their giant...
