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Observing Our Nearest Star, Safely

If you're like me, I'm sure you don't like thinking about mortality. Sobering stuff, but ultimately there will come a day when life -- at least here on Earth -- won't just go on as normal.
/ Source: Discovery Channel

If you're like me, I'm sure you don't like thinking about mortality. Sobering stuff, but ultimately there will come a day when life -- at least here on Earth -- won't just go on as normal.

Thanks to our local star, the sun, we have a finite length of time here on Earth. Eventually, the sun's gonna get us! In a few billion years, the sun will run out of fuel, swell up as a red giant, and scorch our planet.

It seems hard to believe that the big ball of light in the sky that is so crucial to our very existence will one day change the face of Earth and the fate of humanity forever, if we're still here. Taking a closer look at it though, reveals a fascinating view of our nearest star.

BIG PIC: The Intricate Beauty of the Solar Corona

I am always telling people never to look directly at the sun as it can blind you. It generates an incredible amount of power -- obviously the light that we can see and feel as heat, but there's a huge spectrum of other radiation too.

The awesome power output of the sun is down to its immense volume, but its actual power output, volume for volume, is no more than the power output of your average compost heap! Regardless of it's meager 'compost heap' output, looking at the sun is fraught with danger, but with summer fast approaching the northern hemisphere there's no better time to take your first, safe, look.

Safety Warning: Never, ever look directly at the sun with binoculars, a telescope or any other form of magnifying apparatus. Irreparable damage may be caused to your eyesight.

The safest and easiest way to look at a magnified solar image is to use binoculars or a telescope to project an image onto a flat surface, like a sheet of cardboard. If you have binoculars then hold them up to the sun with the bigger end pointing sunward – do NOT look through the binoculars!

BIG PIC: The Sun Does Spectacular Disappearing Act

Place the card about half a meter behind the binoculars so you can see the binoculars' shadow and twist the binoculars until the shadow is at its smallest. You should then see a pair of white disks appear on the card. These are the magnified projected images of the Sun. You will need a steady hand and may need to tweak the binocular focus to get a sharp image. At no point should you look through the binoculars at the sun. If your binoculars are high magnification then you might be lucky enough to pick out some large sunspots on the solar disk.

Telescope projection is probably a little easier as the telescope is held firmly on a mount. If your telescope is larger than 150mm then it is worth making up a mask to cut down the amount of light entering the telescope. Using a piece of card that is bigger than the aperture of your telescope, cut out a circle about 100mm in diameter and then place the piece of card over the front end of the telescope so that the 100mm cutout is over the tube. This will effectively turn your telescope into a smaller one but more importantly will cut down the amount of light entering the tube.


Before pointing the telescope at the sun, make sure you put the lens caps on the smaller finder telescope. The finder telescope, although small, can still greatly amplify the sun's energy; I've seen someone set his beard on fire after forgetting to do this!

Now point the telescope at the sun. To help find it, look at the shadow cast by the telescope on the ground. When the telescope's shadow is at its smallest, it should be almost directly pointing at the sun.

Place an eyepiece in the telescope, lower power is best, and place a piece of white paper or card about half a meter from the eyepiece. DO NOT LOOK THROUGH THE EYEPIECE. With a few final slight movements of the telescope you should see the disk of the sun swing into view on the paper.

A word of warning: Don't leave the telescope pointing at the sun for long as the intense energy can melt the cement (glue) inside eyepieces.

SEE ALSO: How to Choose a Telescope

You can change eyepieces for a more magnified projection to zoom in on sunspots if any are visible. Other than sunspots, which are areas where the sun's magnetic field has burst through the photosphere, look out too for granulation (light speckled appearance of the disk) and faculae (larger areas of light patches) which can all be seen using projection through a telescope.

You can get filters that are fitted to telescopes so you can safely observe the sun without projection, but the only safe ones are filters that fit over the front end of the telescope.

This filter cuts down all the harmful radiation before it gets into the telescope tube. Sadly, some cheap telescopes are still sold with filters that just fit over the eyepiece for solar observing. These are dangerous as they try and filter out the harmful energy when it has already been focused and magnified. They will crack without warning, letting the full force of the sunlight into your unprotected eye.

Alternative, safe filters for observing the sun in white or visible light are made from a material that is coated in aluminum. Mylar is a good example, which is a thin flimsy material that looks like (but isn't) aluminum foil. It's not expensive and it gets fitted over the open end of the telescope. It's this material that you will find on eclipse glasses. You can get more expensive glass equivalents, but these will cost a few hundred dollars (pounds).

If you want to see the sun in a slightly different way, then you can invest in H-alpha observing equipment. You can get either a filter to fit over your telescope or small telescopes that have filter systems built in. With H-alpha gear, you'll be able to see the explosive and violent nature of the sun; prominences, flares and other fascinating phenomena will pop into view. A great entry level H-alpha solar telescope is the Coronado PST.

A final word of warning though, once you start down this road of solar observing, you will have opened up a whole new and fascinating world and will never see the sun in the same light again!