Gamma rays are the highest energy photons on the electromagnetic spectrum. Their wavelength is similar to the size of an atom, and when two of them collide they tend to produce a matter-antimatter particle pair. They represent energy high enough to synthesize the fundamental particles of matter, and are produced in the highest energy environments in the cosmos. The interchange of matter and energy works both ways, so one of the ways gamma rays are generated is through annihilation of a matter-antimatter particle pair. Looking back to the beginning of the universe it gives us the earliest ‘chicken or egg’...
Big stars tend to stick together. They all require incredibly dense regions in which to form, but once they do, they do a great job of blowing away and ionizing any other gas and dust in the vicinity. This is why nebulas in distant galaxies are great tracers of massive star formation. The bigger and hotter the star, the more UV light it produces, the more it ionized a gas cloud, the more we see gorgeous nebula. So it’s no surprise that when I look at the nebula below, I can guess that the central stars are huge, outweighing our...
I always love to chat about stories by close-to-home scientists. I just talked recently about some University of Waterloo cosmological work, but today I can follow it up with a very close to home scientist that I’ve run into a few times. Something about seeing the achievements of those you know makes you feel pride too – it gives us all a good reason to support friends, colleagues, and even acquaintances, since we can share in their passion. Astronomer Lisa Esteves, a PhD candidate from the University of Toronto, has been watching exoplanets carefully with the Kepler Space Telescope, seeing...
On the York Universe radio show this past Monday evening on astronomy.fm, I was having a discussion with another host about how so many things in Astronomy can take Millions or even Billions of years, yet there are still all kinds of phenomena that happen in seconds, hours, weeks, years, or on the scale of human lifetimes. Stars live for hundreds of Millions of years at the low end, yet the intense brightening from the Supernova death of a massive star lasts for only a few days or weeks. It’s as if the Universe is piquing our interest with short...
