Past Articles:

What is a black hole?

A black hole is an area in space that has such a powerful pull of gravity that it sucks everything in it, including light. Nothing that goes into a black hole comes out. If you have ever watched water swirling down a drain, then you have a pretty good idea of what happens as a black hole pulls things in.

Black holes can be big or small. Some are as small as just one atom. Another kind of black hole is called stellar. Its mass can be up to twenty times more than the mass of the sun. The largest black holes are called supermassive. These black holes have masses that are more than 1 million suns together!

The reason it is called “black” is because the light that is sucked in cannot get out. Although we are unable to see black holes, they can be detected because of their effects on the surrounding stars.

What are Supergiants?

Supergiantsare the biggest stars in the entire universe. They consume hydrogen at an enormous rate. As they start running out of nuclear fuel, they shrink and grow hotter. This translates into a lot of stored energy. When the star dies, which happens fast, the energy is released in a violent explosion called a supernova.  

Why is the color of the sun yellow?

The color of a star depends on how hot it is. When you light a fire, the coolest part of it, which is at the top of the flame, is red; the hotter part, which is in the center, is yellow; and the hottest part, which is at the bottom, is blue. It’s the same with stars. Yellow stars like the sun are in the middle of the heat range, with a temperature of about 10,300 degrees Fahrenheit. Some areas of the sun, called sunspots, appear darker, because they are cooler than the rest of the sun.

Question of the Month:

This month’s question was submitted by Jack of Brooklyn, NY.

Q: Dear Professor, Does the sun have a solid surface like the Earth?

A: The sun is a ball of gas, so it does not have a solid surface like the Earth.