ETX on sale at the

Discovery Store

ASTRO WORDS AND TERMS

Optical Telescope: A telescope used for a human to look through

Diameter or Aperture of the telescope is the key to how far out there you can see!. Aperture is the single most limiting factor of a telescope. Clarity of the atmosphere being second. This is why the majority of the large research telescopes are humongous Reflector type telescopes placed as high as they can get them! Usually on top of a mountain in a dark area.The air is less polluted the higher you go.

Focal Length Very basically, focal length is not how long your scope is, but how far the incoming light has to travel from the entrance of the telescope to your eye. Hence focal length. Or sometimes referred to how fast the telescope is. This is the time it takes light to travel that optical path.So, a telescope with a shorter optical path is faster than a scope with a longer optical path. This is known as an F Ratio. So a scope with a focal length of F4 will be a faster scope than an F10. That is as far as we will take that for now. You will need to learn more about Focal Lengths and F ratios later and how they affect the usability of your first scope. Focal Length

Magnification: Very basically is the ability to make an image larger in appearance (not in physical size) in order to see more detail. The higher magnification the more detail

Magnification Power:The degree of magnification is the difference in power you give your telescope to magnify the image! Divide the focal length by the eye piece gives you magnification of your telescope.

These are some great places to get the meaning of any astonomy terms

GLOSSARY FOR BEGINNERS

We will update this list often so check back soon!

Next Astronomy Forums

Back to Astronomy Etiquette