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CURRENT MOON PHASE
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Page listing for the category: Stars
Some stars that we can see in the sky, vary in brightness quite noticably over time.
Their brightness may alter by several magnitudes over a period of days, weeks or months.
One of the most famous variable stars is Algol, in the constellation of Perseus (Beta Persei). Algol is markedly red in colour and varies by about one magnitude, over the course of a few days. read on..
There are many stars in the sky which look like single points of light to the unaided eye. But these special stars are in fact doubles, or even sometimes triples or more, when viewed through binoculars and telescopes. read on..
A system of magnitude numbers (mag for short) is used to classify the brightness of the stars we see in the sky.
This magnitude system was actually first devised by Hipparchus, the Greek astronomer, a long time ago in the second century BC.
It is based on the principle that the stars we can see with the unaided eye, should be classified between magnitude 1 for the brightest and magnitude 6, for the faintest. read on..
