One way to make written information a little bit different is to use an acrostic. In an acrostic, the initial letters of a key word connected to the theme are used as the first letter of each piece of detail. This acrostic, full of mind-boggling facts about stars, is based on the letters in the word STARGAZING – something we hope that you will be able to enjoy during dark but clear nights this winter!
Stars are made up primarily of about ¾ hydrogen and ¼ helium. Over time, stars will convert some of their hydrogen into more helium.
The Sun, with a diameter about 109 times bigger than that of the Earth, is our closest star although it is some 150 million kilometres away. It takes light from the Sun just over eight minutes to reach us on Earth. When the Sun runs out of fuel it will become a red giant, bloating up many times its current size.
Although it may look as though all the stars out there are by themselves, many come in pairs (binary stars) where two stars orbit a common centre of gravity! Some systems may even have three or four stars in close connection like Alpha Centauri (Dog Star) reckoned to be the nearest to Earth apart from the Sun.
Red is actually the coolest colour of a star although it may seem like a hot colour to us. Next up in heat intensity are stars like the Sun with an orangey-white blend, while the very hottest stars are actually blue.
Good nights for stargazing are when the sky is free of cloud and there is no Moon. You should be able to start an hour or two after sunset. Try to view the stars in open countryside where there is little or no light pollution from streetlights, traffic or buildings. Good eyesight should give you a comprehensive view but the use of binoculars or a small telescope will help even more.
A star like Alpha Centauri (see above) is located over four light years away. It takes light from there more than four years to complete the journey to Earth! If you tried to hitch a ride on the fastest spacecraft ever launched from Earth, it would still take more than 70,000 years to get there from here.
Z is the letter used to name some nine stars in the night sky. The best known are Zaniah in the constellation Virgo and Zosma in Leo. Others include Zhang (Hydra) and Zembra (Aquarius).
It may seem like it, but stars don’t actually twinkle. The effect is caused by the Earth’s turbulent atmosphere. As light from the star passes through the atmosphere, especially when the star appears near the horizon, it must pass through many layers of often rapidly differing density. This deflects the light in colour and intensity and this causes the ‘twinkling’.
Numbers of stars in the sky on clear nights are misleading. You certainly can’t see millions of them. There simply aren’t enough stars bright enough and close enough to total one million. The number on a good night might be more in the region of 2,000 to 2,500 at any one time.
Good use has been made of the stars by humans, even from the very earliest times. They have been used in religious practices and astrology (star signs), the design of early calendars and as a navigational aid on land and sea before the development of measuring equipment.
Try making up short poems using an acrostic of the word STAR or something else connected to the Science of Stars theme.
Here’s a simple example to get you started:
Stars up in the sky
They sparkle with joy
All so bright and luminous
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Words: John Davis