How to use a Star Chart

So you’ve just bought yourself a telescope, set it up in your garden and took that first look through the lens.  Do you have any idea what you are looking at though?  Probably not, so what you need to do is to invest in a sky chart.

A sky chart is probably the most useful and the cheapest piece of star gazing equipment you will ever buy.  The chart is quite simply, a guide or map of the night sky.  There are several types, the first one described here is a star chart called a planisphere.

A planisphere star chart consists of two cards; the top card represents the night sky, and shows all the constellations.  The bottom card allows you to adjust the view according to the time and date.  A centre rivet attaches both cards to each other, and once you adjust the card to the proper date, you are ready to identify the night sky.

The chart can be held over your head, with the compass points on the chart matching the cardinal points around you.  So south on the chart will match south in the sky.  It is easier to read the chart if you face north, so once you have found the pole star, you should be able to orientate yourself and your telescope to find any other stars or planets.

You can now identify the constellations by picking out the larger and brighter stars in the sky, and matching them on to the chart.  Taking an imaginary line from the pole star to the star you are looking for will allow you to understand what you are seeing more easily.  If you remember that the star chart is just a map, and can be used the same way as you would any other map.

Star charts can also be found in book form, with a chart for each month of the year.  Pick the correct chart, and then just use the chart in exactly the same way as the planisphere chart.

There is a more modern high-tech forms of the star chart.  These are software programmes, some of which are available as free downloads.  These charts are read the same way as the other star charts, but fortunately, it is designed so that you don’t have to hold the laptop screen above your head to do so.  This software offers almost unlimited variation and adjustment.

The software can be adjusted to show the constellations visible from your exact co-ordinates, and at any time of day or night.  Having these extra features means that you can plan your star gazing to get the maximum viewing by choosing the best day and hour to set up your telescope.  The charts can be printed out and taken with you for reference when you are star gazing.

Whichever style of star chart you decide to use, it will make your star gazing more pleasurable, and like a road map, stop you floundering and getting lost.