Learning the stars

Andrew Harris — 11 July 2011

ONE OF THE GREATEST pleasures of leaving the big smoke behind is the clarity of the night skies. Out of major population centres, it’s always a city slicker’s intrigue to have a full blanket of stars when you’re swaddled in your own covers or knocking back the last cuppa of the evening. Perhaps you’ve even picked out the Southern Cross, or pondered our position in the Milky Way, or witnessed a shooting star. Whatever your experience, with a bit of information and a few handfuls of equipment, the inky black beyond will reveal itself into a whole new, very interesting world.

Although it would pay to have a high-powered telescope attached to your rig, all you need to chart your way across the night sky is a pair of binoculars. Astronomical Society of Victoria president Perry Vlahos says binoculars are a key bit of RV kit.

“Binoculars are an essential item to take with you in your caravan,” he says. “They’re easy to use, and you can also use them for terrestrial viewing. They’ll give you fabulous views of the sky outside of capital cities.”

He says that binoculars offer “instant satisfaction” for a first-time astronomer. He advises to opt for a 7x50 pair (seven times magnification and a 50mm front lens element) if you’re aged under 35, or a 10x50 pair (10 times magnification and a 50mm front lens element) if you’re older. That’s only a rough guide, though, and you should try for yourself to see what suits you best.

Perry writes and talks about astronomy and, as he puts it, teaches teachers how to teach astronomy. He’s also regularly on the radio. “I’m the bridge between amateur and professional astronomy,” he says.

And this all stems from an interest raised in a secondary school science lesson.

The best pairs of binoculars for stargazing have as big an aperture as possible (50mm and above), meaning the front lenses can become rather large. The bulk is necessary to gather the maximum amount of light, which is essential for night-time viewing of often faint objects. Ultra-large aperture binoculars are available, and require special tripods and counter-balanced mounting systems.

For hand-held viewing, Perry does not recommend you go above 10 times magnification because you can’t easily hold them still. Some opine that lower magnification is less tiring on the viewer and ultimately not much of a compromise anyway. And with regard to price, when it comes to viewing the cosmos, prices can go from budget to, well, astronomical.

Telescopes, though, are the natural choice for astronomy. For larger models, you’ll have to take into account the need for a tripod, and you’ll need a safe, stable place to store one in your van or motorhome, but you’ll have a much more rewarding astronomical experience than with a pair of binoculars. Fortunately, though, it’s not size that matters: what counts is what you do with it.

Perry’s suggestion is on the modest side. “A 6in [15cm] Dobsonian telescope is the smallest I’d recommend,” he says. “It has a large enough aperture and it’s compact.”

This will set you back around $400, and is perfect for travel. “They’ll survive pretty well in a caravan,” Perry says, “so long as you’re not banging them up and down all the time.” And, he underlines, never fear a little travel grime: telescopes can be used without noticeable difference when their lenses are very dusty.

Observatory and hand-held models alike need professional, specialist cleaning. “Don’t ever touch the optical surfaces,” Perry warns.

A Dobsonian telescope (also known as a Newtonian telescope) uses mirrors, rather than lenses, to magnify the subject. A refractor telescope is the type that employs lenses, while a catadioptric uses a combination of lenses and mirrors.

In order to gain an understanding about what’s embroidered on the heavenly canvas, you can try a star atlas. Although there are many printed star atlases available, Perry recommends an electronic version available via www.skymaps.com. He says interested people should log on and download a one-page map of the southern hemisphere for each month they’ll be on the road – easy and free.

When you’re in the field with these printouts, you’ll need an extra tool in your box: a red-light torch. The standard white or yellow torchlight that you might think suitable for illuminating your charts will rapidly constrict your pupils, meaning that the night vision you’ve taken half an hour to acquire will disappear in a second. Red light doesn’t have the same effect.

You can buy a professional red-light torch, or make your own, but it’s essential for efficient night-time viewing. To make your own, use a rubber band to fasten some red cellophane or red tissue paper over the head of your torch.

When you’ve got your personal observatory up and running, you may well make a significant, if unexpected, contribution to science. Amateur astronomers regularly aid scientific bodies by tracking comets and other objects, and might occasionally discover a new star. If you do, you can name it.

Two of the biggest names in amateur astronomic discovery are SA’s Reverend Bill Bradfield, who discovered 17 comets, and keen-eyed New South Welshman Bob Evans, who stumbled across some supernovae.

Perry attributes the success of amateur stargazers to their willingness to “look at things that professional observatories don’t have the time for”.

A long journey begins with small steps, and you’ll take the first few immediately if you start with a telescope. Trading up from binoculars, and with careful viewing away from urban light pollution, you’ll be able to see the rings of Saturn, the moons of Jupiter, craters on the moon, clusters of stars, and huge clouds of gas.

“Fabulous vistas can be viewed along the Milky Way,” Perry says. “Being outside the city will give you an unparalleled view of the sky. All of a sudden you have five times as many stars – the further you can get away from city lights the better.”

With binoculars, you’ll still be able to spot Mercury, Venus, Mars, Jupiter and Saturn. With a bit of help, you can find Neptune and Uranus, as well as asteroids, comets and planetary moons. On a dark night in the country, even with the naked eye, you can peek at galaxies and nebulae. And wherever you view from in Australia, you’ll have access to pretty much the same stuff. In the farthest north, though, you could have the chance to peek into a patch of the northern hemisphere.

Still, while you’re sure to be impressed by what you find, you shouldn’t have an unreasonable expectation of what you will see. You’re not going to get the up-close, hyper-saturated, vibrant imagery of an astrophotographic coffee-table book; much of that colour comes from long exposures and extreme magnification. When you look through a telescope with your own eyes, you’ll only see a hint of the same hues, and an outline of the shape of an object.

Regardless of where you’re located across this wide-skied land, making contact with your local astronomical society is a good first step. For starters, joining your local society could allow you access to a Dobsonian telescope for three months at a time – perfect for deciding if you want to invest in your own hardware.

If you’re more DIY-inclined, clubs can teach you to make your own stargazing solution, and if you’re into happy snaps, you can begin to learn the art of astrophotography.

The Astronomical Society of Victoria, for example, maintains a huge library with books, magazines, DVDs, star atlases and more, and an events calendar that is just as full and varied. There are plenty of things happening, and Perry says it’s all very friendly, with a diverse membership that bridges age gaps.

“We’ve got young kids, we’ve got old kids; everything from housewives to university professors, and all stations of life in between,” he says.

The society runs trips to ideal viewing sites, distributes tips on what is available to see and when, offers gear guidance, and can lead you on the path to discovering your first comet.

Show someone a star and they’ll be engaged for a night, it seems. But teach someone to star-gaze, and they’ll be hooked for life.

Source: Caravan World May 2009.


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