Solar Observing FAQ
What kind of filter are you using on the telescope? Why does the Sun look red through your telescope?
The filter we generally use is called a Hydrogen Alpha Filter. The filter system rejects all but one specific color of red light coming from the Sun. This is why the Sun appears red in the view. Some of our telescopes use white light filters. Through these telescopes the Sun will look yellow or white. Either way, you are seeing less than 1% of the light of the Sun through the telescope.
Can we see anything else in the telescope besides the Sun?
Not really, at least not during the day. The solar filter would have to be removed before anything else would be visible. However, it is possible to see the Moon, Venus or Jupiter during the day if they are in your sky and you know where to look. At night of course, we can see the planets, multiple stars, nebulae, star clusters and other galaxies.
Why don’t we see any other stars in the telescope view with the Sun?
The solar filter prevents us from seeing any other stars behind the Sun.
What are the black spots on the Sun?
The black spots on the Sun are called sunspots. They are places where the magnetic field of the Sun has pushed away some of the heat. The sunspots are cooler than the rest of the surface, so they look black.
How hot is the Sun? How cool are the sunspots?
The Sun’s surface is about 11,000 degrees Fahrenheit. The sunspots are about 2,000 degrees cooler than the surrounding material.
Are those flames shooting off the side of the Sun?
No, not really. The Sun is not on fire the way most people think. The red projections coming off the Sun are prominences. Prominences are formed by charged material following the magnetic field lines close to the surface of the Sun. They often look like big loops over the surface, but they can have many other shapes. They can last for weeks at a time.
How far away is the Sun? -OR- How long does it take the light to get here?
The Sun is an average of 93 million miles away from the Earth. The speed of light is 186,000 miles per second, so it takes about 8 minutes for sunlight to reach us. Through our telescope, we are actually looking at the Sun as it WAS about 8 minutes ago.
Is this really the Sun in your telescope?
Yes, you are really looking at the Sun through the telescope. It is not a picture.
How old is the Sun? -OR- How long will the Sun last?
Scientists estimate that the Sun is about 5 billion years old, along with most everything in our solar system. It seems to be about halfway through its lifecycle.
How do we know how old the Sun is?
Scientists have studied many other stars in our galaxy, including stars similar to our Sun. Based on what these other stars have taught us about stellar lifecycles, and on how much hydrogen the Sun seems to have left, we think the Sun is about 5 billion years old. But there is no way for us to be sure!