So far, on Science Burrito, I have tried to give a fun and unique spin to the science I have shown you. This is good. It makes it more fun for you, the reader, and more fun for me, the writer. Today, I wanted to be a bit more straight-forward. My degree is in Astronomy, but life happened to steer me away from that path and into the line of sight of lasers (eek!). This is fine, because lasers are awesome and I love my job, but sometimes, I miss the stars. I still have my telescope, and hopefully at some point in the future, I will start an astronomy section where I bring pictures from my star-gazing. For now though, I wanted to show you the wonderful, varied and cosmic nature of the universe. So strap in, and come with Science Burrito, on a trip to the stars…
While you are enjoying the video (which, if you’re anything like me, you are currently watching on repeat) here are a few facts about the stars you are looking at.
Most of the stats I have presented in comparison to our own star, The Sun, so here are some numbers to put those stats into context:
The Sun’s mass is 2000000000000000000000000000000 kg! That is, 333,000 times heavier than the Earth.
When I say “size” in the video, I mean radius, the distance from the centre, or core, of the Sun, to its surface. In the case of the Sun, this is 695700 km, or 109 times larger than the Earth, or nearly twice the distance between the Earth and the Moon.
Barnard’s Star is one of the closest to us in the night sky, but is very dim as it is very cool. It is only 6 light years away, which means if we travelled at the speed of light, it would take us 6 years to get there. The fastest speed people have ever travelled is 0.004% the speed of light. At those speeds, it would take us over 160000 years to get there.
Epsilon Indi is actually a triple star system. It is orbited by two other stars, called Brown Dwarfs. These are so small and cold that they hardly emit any light at all so we can’t see them in the night sky.
Procyon is a star very similar to our own Sun, which would make it an exciting prospect to find life! Unfortunately, it has a companion star (as, it turns out, most stars do), which in this case is a closely orbiting White Dwarf. This makes it very hard for life supporting planets to get a stable orbit in the ‘goldilocks’ zone – the distance from the star where it is not too hot for life, nor too cold for life, but is just right.
The stars’ positions in the sky are not fixed, although they appear to be to us. They are in fact drifting through space and so slowly moving position in our sky. 14000 years ago, Vega was where the Pole Star is today and could have been used to find North by early Man.
Achernar is round in my video because it looks more like a star that way, but it is not round really. It spins so fast (one ‘day’ on Achernar, or one full rotation, would only take about 9 hours, but it is over 1000 times bigger than Earth, which takes 24 hours!) that it is not spherical at all, but flattened like a discus.
Alnitak, besides having a very silly name, is the brightest type-O star in the sky and is the left most star of Orion’s belt.
Red Giants and White Dwarfs are kind of special in that they once used to be stars like our own sun. When stars reach the end of their life, the start to expand and glow a deep dull red (a lot like some people do 😛 ) as they begin to run out of fuel. Eventually, they get far too big for their boots and collapse back in on themselves. This causes them to heat up very rapidly and then they quickly go from imploding to exploding in a giant explosion called a super-nova. After that, sometimes, a small star made up of just the core of the star that exploded, is left behind. That is a White Dwarf. When our own Sun expands into a Red Giant, it will become so big it will swallow up the Earth. But don’t worry, that won’t happen for billions of years yet.
There are many other different types of stars and objects out in space, and they are all really, really interesting. But these are the main ones that shine enough for us to see in the sky. I’ll tell you all about the others another day. For now, go outside and look up into the night sky and realise that all those stars that look so similar from here are all really very different close up. Happy stargazing!