Biggest star in the universe
Firstly, lets get things into perspective. The sun is the nearst star to our Earth. It’s located about 150 million kilometers (8,2 minutes at the speed of light or 0,0000152 light years) away from Earth. The sun has a surface temprature of about 5.500 °C and its mass is 1.98892 × 1030 kg. That is 1.988.920.000.000.000.000.000.000.000.000 kg. There are days I lift less mass. Also the sun is the brightest star in space we can see from Earth.
Now, bigger stars.
There are two stars in the known universe that can be the biggest one. Firstly there is Eta Carinae from the Carinae constellation.
Facts about Eta Carinae
- Constellation: Carinae
- Size: 800 times our sun
- Distance: Roughly 7.500 light years from Earth
- Mass: 100 times more than the sun
- Brightness: 4.000.000 time the sun
- Surface temperature: 12.000 °C – 55.000 °C
So, basically it says that Eta Carinae is really big, really far away, quite heavy and very very bright and doesn’t sound like the perfect place to live. Even less because Eta Carinae can go supernova any moment. The spheres around the star give a nice view, but don’t really have a “come live here, it’s a pleasant place” ring over it. And as often things are exactly the way they seem.
Eta Carinae is possibly the biggest star in our known universe. There is a star that might be even bigger. VY Canis Majoris. Estimated size from 600 to 2.100 times the sun. Because it’s possible we’ll assume it’s 2.100 times the size of the sun.
Facts about VY Canis Majoris
- Constellation: Canis Majoris
- Size: 2.100 times our sun
- Distance: Roughly 5.000 light years from Earth
- Mass: 30 times more than the sun
- Brightness: 500.000 times more than the sun
- Surface temperature: 3.400 °C
- Fun fact: It would take light 2,7 hours to travel around VY Canis Majoris circumference.
VY Canis Majoris is also a dying star. It is already ejecting material. So, it will go supernova too. For those who don’t know yet here is supernova in a nutshell.
When a star is out of fuel (in case of VY Canis Majoris that is hydrogen) it will result in an unbalanced gravitational pressure due to the lack of energy. Stars will grow size just before they run out of fuel, but go supernova when there is no fuel left. Meaning a huge explosion followed by an implosion of the star and eventually, but not always, resulting in a black hole.
Consequences for Earth
When Canis Majoris goes supernova we’ll be able to see it from earth. In the worst case also notice it. Gamma rays can reach earth and distroy all life on it. I’m not saying that it will happen, just that it’s possible. There is not THAT much to worry though. Important for the magnitude of the supernova is the mass of the star. Since VY Canis Majoris only has 30 times the suns mass we’ll probably be fine. Eta Carniae is much more dangerous then. Luckily for us it’s predicted that the explosion, for the biggest part, will not go earth’s direction.
To put things into perspective even more, see a very nice picture below that I used from wikipedia.