Welcome, guest. You are not logged in.
Log in or join for free!
Stay logged in
Forgot login details?

Stay logged in

For free!
Get started!

Multimedia gallery

knockintele - Newest pictures

Back Garden Astronomy

The image above is of the Knockin Radio Telescope in Knockin, Shropshire, on the England/Wales border. I happened upon it whilst driving to my girlfriend's parents house.
I researched the telescope and found that it's a part of the MERLIN (Multi-Element Radio Linked Interferometer Network) array of radio telescopes distributed around Great Britain, all operated by Jodrell Bank Observatory.
Not everybody has a radio telescope in their back garden. Or even a telescope for that matter. Most of us do, however, possess a pair of binoculars of one kind or another. That is what this page is all about.
Looking at the stars with just the naked eye, there are only a handful of stars that show colour. Most obvious to me is Betelgeuse, the brightest star of Orion. But just looking through a pair of binoculars will show the colours more pronounced. My personal favourite is the bright star, Vega, in the constellation Lyra. Through binoculars its deep blue, i can't help but point my binoculars to the beautiful hues of Vega.
Colour depends upon surface temperature. White heat is hotter than yellow heat, yellow is hotter than red. The surface temperatures range from below 3000 degrees Celsius for the coolest red stars, and over 50,000 degrees Celsius of the very hot stars which are white or bluish.
The German optician, Joseph von Fraunhofer was the first to study the Sun's spectrum in detail, in 1814, the dark lines, or absorption lines are known as Fraunhofer lines. Later, around the end of the 19th century, the spectra of other stars were examined by astronomers at Harvard College Observatory. The spectral types were given letters of the alphabet, as follows:

O: very hot stars, greenish-white or bluish-white. O-stars are rare.
B: hot white stars.
A: cooler white stars.
F: slightly yellowish.
G: yellow stars.
K: orange stars.
M: orange-red stars.

There are a few more types but they're extremely rare. The types above are always used.
The strange...

This page:

Help/FAQ | Terms | Imprint
Home People Pictures Videos Sites Blogs Chat