Clarens is renowned for its fresh mountain air and as a result our starry skies are absolutely impeccable. Why not follow and learn from them then?

A Beginners Guide to watching the stars

The sky is filled with mysterious and fascinating things. We can observe the wonders of the sky with the aid of telescopes or by the unaided eye – did you know that you can see a galaxy 2 ½ million light-years away with your unaided eye? All these wonderful marvels can be observed and enjoyed, all one has to do is look up and ask, “What’s that?”, and a lifetime of cosmic exploration will unfold.

When starting to follow the movements of the stars, or trying to spot constellations in the sky, there are a couple of valuable tips one needs to follow.

 – Use a Star Chart

Star charts are a bit like road maps that help us find our way, instead constellations, stars and planets act as our road signs. Although star charts may be a bit daunting to use at first, it later becomes one of the easiest ways to learn the starry skies.The most important thing to remember is to use the correct star chart according to the month, time of year and season. Sky maps are easily available online and Starmaps provide some of the most accurate maps available.Determine what direction you are facing and point the star map accordingly. If you are facing south the southern hemisphere of the map should show as well. The compass on the map may look like it’s the wrong way round, but the trick is to hold the map over your head and look up, as the map is that of the skies the compass will now be correct.

 – Get a Twinkle in your eye

Familiarize yourself with the patterns in the sky on any clear, dark night. Constellation maps are easily available online and we at Clarens News will post one constellation per week to ensure that none will be disappointed.The ability to look up and name a constellation provides pleasure and a sense of one’s place in the cosmos that will last a lifetime.

 – Start with Binoculars

There are multiple reasons for using binoculars as a first telescope. Not only do they give a wide field of view, ensuring that one doesn’t get lost, but they also show the sky the right side up making it easy to see where you are pointing. Binoculars are fairly inexpensive, versatile and their performance remarkably respectable. Larger front lenses are ideal for astronomy and high optical quality is of importance too, but any binocular will be sure to launch your amateur-astronomy career.

 – Use guides and maps

Binoculars can keep one busy for years and with the use of maps and guides one can identify many miracles in the sky. When you know where and what to look for, you will be able to observe galaxies, star clusters and nebulae, track the movement of Jupiter’s moons and the crescent phases of Venus, and even follow the fading and brightening of many variable stars.

  – Seek out other amateurs

Stargazing is a wonderful interest to share with others and as long as you remember to have fun, you’ll soon know your way around the sparkles in our magnificent sky.

Getting started

–       What are constellations?

A constellation is a group of stars that together form an imaginary picture in the sky. Constellations are usually named after mythological creatures, characters, animals and objects, and finding them is like a game of connecting the dots.

–       Important words to know

Sky Measures

Beginners often have trouble describing distances in the sky; the problem is that these distances can’t be described in linear measures such as meters or kilometers, thus angular measure as result.

Astronomers might say the two stars are 10 degrees (10°) apart. That means if lines were drawn from your eye to each star, the two lines would form a 10° angle at your eye. Simple!

Hold your fist at arm’s length and sight past it with one eye. Your fist from side to side covers about 10° of sky. A fingertip at arm’s length covers about 1° and the Sun and Moon are each 12cm wide.

There are finer divisions of angular measure. A degree is made up of 60 arcminutes, and each arcminute is made up of 60 arcseconds.

Sky Coordinates

If the earth beneath us had to vanish, we would be suspended in the middle of a star-speckled sphere. The positions of the stars are designated by where they are on this celestial sphere.  Imagine the earth hanging in the middle of this sphere, and the longitude and latitude lines ballooning outward into the edges of the sphere. These lines now form a coordinate grid on the sky that can tell us the position of a star. In the sky latitude is referred to as “declination” and longitude is called “right ascension” and these terms are the standard celestial coordinates.

Brightness

The word magnitude refers to the brightness of a star and this term will be encountered many times.  Stars are divided into brightness classes starting from 0 and under as “1st magnitude”, and continuing upward as the stars gets dimmer. Vega is zero (0) magnitude, and Sirius, the brightest star in the sky, is magnitude –1.4. Venus is even brighter, usually magnitude –4, the beautiful full Moon shines at magnitude –13, and our warm, nourishing Sun at a magnitude of  –27.

Distances

The Earth orbits the Sun once a year at a distance from the Sun averaging 150 million kilometers. That distance is called one astronomical unit (a.u.). It’s a handy unit for measuring things in the solar system.

The distance that light travels in a year — 9.5 trillion km, or 5.9 trillion miles, or 63,000 a.u. — is called a light-year. Note that the light-year is a measure of distance, not time.

Most of the brightest stars in the sky lie a few dozen to a couple thousand light-years away. The nearest star, Alpha Centauri, is only 4.3 light-years away. The Andromeda Galaxy, the nearest large galaxy beyond our own Milky Way, is 2.5 million light-years distant.

Professional astronomers often use another unit for big distances: the parsec. One parsec equals 3.26 light-years. (In case you’re really wondering, a parsec is the distance where a star shows a parallax of one arcsecond against the background sky when the Earth moves 1 a.u. around the Sun.)

A kiloparsec is 1,000 parsecs, and a megaparsec is a million parsecs

Watch out for regular articles in Clarens News about the constellations visible from Clarens.

 

Genevieve

Article written and researched by

Genevieve Blignaut

Clarens News:  November 2013