3 minute read
telescope 101
NAVIGATING THE TYPES OF TELESCOPES
By: Lusanda Tamesi
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Under the clear skies on a rocky arid outcrop, far away from the clustered town with light pollution, I needed some "time off" from everything. To my surprise, something shiny in the sky caught my attention. How can I get a clear and closer view? Why are those shiny objects forming a box?
“You need a telescope for a clearer view,” said a passerby.
But, which telescope would be best?
It all comes down to how much money you are willing to spend on a telescope. Which telescope do you think would be ideal for you? Are you driven by brand names? What exactly do you want to look at with this telescope? Are you looking to search for fuzzy or faint celestial objects? And then there is size. What size would work best for you?
In the family of telescopes we have radio telescopes, x-ray telescopes, gamma-ray telescopes and optical telescopes. There are different types of telescopes – big, small, professional astronomy ones and those for amateur astronomers. Our focus will be on optical telescopes that you can even use at home – in your backyard.
Refracting telescopes
Also known as dioptric telescopes, these are optical telescopes used by professional astronomers. They are often big and expensive. They are convex in the eye and concave in the end. Their main categories are Achromatic and Apochromatic.
Pros:
- Easy to use since adults can use it while sitting and kids can use it with ease as the eyepiece is placed at the bottom instead of on top -It’s sturdy, made of harder material - Easy to maintain - Lenses do not require much maintenance
Cons:
- Chromatic aberration (achromatic refractors suffer from chromatic aberration, can produce an inexact series of colours thus affecting image quality that is solved by apochromatic refractors) - Pricing depends on how big the lenses are – the bigger the refractor, the more expensive the cost of an aperture - The weight can be a challenge – some of these are longer and heavier thus making it difficult to transport.
Compound telescopes
The "topdog" of telescopes – catadioptric or compound telescopes are hybrid telescopes that mix refractor and reflector elements in their design. They are named after German astronomer Bernard Schmidt, who made the first compound telescope.
Pros:
- Compact size (light, and easy to carry) - Great optics
Cons:
- High price - Collimation and maintenance
TELESCOPES IN AFRICA *Southern African Large Telescope (SALT) in SA * The Telescope of Kottamia Observatory in the Middle East Hess * Optical Telescope in Namibia * Marly Telescopes in Burkina Faso * MOSS in Morocco * Nigeria Radio Telescope * Ghana Radio Telescope in Accra
(Image credit: Meade instrument)
An observer with a bubbly personality that pinpoints star images giving off detailed planetary observations. Meade ETX90 Observer is good for traveling, observing terrestrial life and astrophotography. This darling cannot rest as it gives off close-up views of planets and star clusters and audio that is over four hours; educating you on what you are observing with its AudioStar GoTo system built-in speaker. The Meade can make observations exciting, whether from your backyard or on the go.
