| VY Canis Majoris | Star Size Comparison: The biggest/largest known stars in the Universe. VY Canis Majoris (VY CMa) is a red hypergiant star located in the constellation Canis Major. With a size of 2600 solar radii, it is the largest known star and also one of the most luminous known. |
| OGLE-TR-122b | The smallest known star right now is OGLE-TR-122b, a red dwarf star that's part of a binary stellar system. This red dwarf the smallest star to ever have its radius accurately measured; 0.12 solar radii. This works out to be 167,000 km. That's only 20% larger than Jupiter. |
| Eta Carinae | Eta Carinae could be as large as 180 times the radius of the Sun, and its surface temperature is 36,000-40,000 Kelvin. Just for comparison, 40,000 Kelvin is about 72,000 degrees F. So it's the blue hypergiants, like Eta Carinae, which are probably the hottest stars in the Universe |
A star is a luminous sphere of plasma held together by its own gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye from Earth during the night, appearing as a multitude of fixed luminous points in the sky due to their immense distance from Earth.
1. Many stars you look at in the night sky seem like single, distant glimmer of light. However that is not the case. Most stars you see in the night sky are actually two star systems, or binary star systems. They are so far away however that they just appear as one speck of light.
2. Stars go through many phases of life, much like other organic beings. When a star is dying, it turns into a “white dwarf”, when the star uses up all of the chemicals required for its nuclear fusion reaction, it will fuse a large clump, which will emit white light until it finally darkens for good.
3. Before a massive star goes into a white dwarf phase however, it undergoes an incredible chain reaction in which it burns through the rest of its fuel at a dramatic pace and explodes due to the speed of the reaction. This reaction is known as a supernova.
4. If a star is massive enough, after it goes supernova it can actually turn into a massive, gravity and light eating black hole.
5. Contrary to popular belief a black hole does not “suck” in the objects around it. Due to their incredible mass, according to Einstein’s general theory of relativity, they actually bend space in such a way that everything within their gravitational field is pushed towards it. A black hole’s gravitational field is so strong that even light cannot escape it.
6. If a star has enough mass, it will burn up much like a white dwarf. Instead of fading away however, it will go into a state of degeneration, these stars are rare and are called “neutron stars”.
7. Neutron stars are extremely easy to recognize. Opposed to white dwarves they are easy for astronomers to spot through telescopes because they bend the light around them, which allows them to be seen easily through infrared telescopes.
8. There are some stars that are 100 times more massive than our Sun. These stars also can output about a million times more energy than our sun, while still maintaining the same radius.
9. Eta Carinae is one of the largest stars in the known galaxy, it is designated as a hyper-giant.
10. Another hyper-giant star is designated as Pistol, it shines even brighter than Eta Carinae, at about 10 billion times more than our sun. It emits such high amounts of radiation that scientists have already declared it impossible for anything to live in such a system.
11. The closest observable star is Sol, or as it’s more commonly known, the Sun. Although it is around 150 kilometers away, there are billions of stars just like our Sun out there in the galaxy
12. The distances involved in measuring how far away a star is are immense. Consider that the closest star to Earth is approximately 4.2 light years away. It would take about 70,000 years in our fastest space craft to reach it.
13. There are approximately 400 billion stars in the Milky Way galaxy alone.
14. On a clear night, you cannot see even a fraction of these stars. However during a clear night, in the country, with the naked eye you can see up to 19,000,000,000,000,000 miles away, very easily.