This summer, try amateur astronomy

By Tom Seymour | Jul 23, 2017
Photo by: Tom Seymour Tom's refracting telescope, fitted with a sun filter for viewing eclipses and sunspots.

We in Maine are more fortunate than many realize. Maine enjoys dark skies, undiluted by artificial light. During nights when the atmosphere is stable and fog or cloud cover doesn’t interfere, a person almost anywhere in Maine can look up and clearly see the Milky Way, our home galaxy.

It is sad to note that in so many places in our country, people live their lives out without ever seeing the Milky Way. But here, we can revel in the sight of a river of stars running across the sky, far too many to count, and so numerous as to defy our ability to fully appreciate them.

And within the Milky Way, we can plainly see a ribbon of black, separating this “star river.” It’s called the Great Rift and it effectively blocks out everything behind it, at least from our point of view here on Earth.

Pareidolia, the phenomenon responsible for people's seeing images in clouds and the man in the moon, also works for us as we try to visualize the various geometric, random and fanciful shapes we see in the night sky.

Some of these shapes are, indeed, constellations. In 1930, the International Astronomical Union chose 88 official constellations. These include every star in the heavens. And while a star may belong within the boundaries of a certain constellation, it may not be part of any recognizable pattern.

Some easily recognized patterns are not constellations, but are called “asterisms.” Prominent among these are The Big Dipper, an asterism in Ursa Major; The Summer Triangle, formed of stars belonging to three different constellations; and The Northern Cross, a group of stars in the constellation Cygnus, the Swan.

Add to this the planets and deep-sky objects, such as star clusters, galaxies and nebulae, and we have enough viewing to satisfy the most eager amateur astronomer.

Here, then are some suggestions for how, when and where to begin this exciting journey into the nighttime skies.

1. Naked-eye viewing

You don’t need optical aids to enjoy the heavens. Your eyes can take in enough to fill an entire evening under the stars. The first goal here is to learn to recognize as many constellations as possible. To do this, either download an astronomy app for your smartphone, or send for a planisphere. A planisphere is a device that looks like a wheel, with numbers on the edges. Another wheel, movable and attached to the larger circle, can accurately indicate all constellations within your sphere of view. Just align the dates and numbers (it’s easy, and besides that, directions are included) while holding the planisphere up to the sky and you can begin to nail down one constellation after another.

Planispheres are available from astronomy shops everywhere, as well as from many gift shops. Amazon sells several good-quality planispheres at very reasonable prices.

It’s hard to describe the feeling of accomplishment when, after a few nights, you can accurately name most of the constellations in view.

2. Binocular viewing

The next step in your development as an amateur astronomer is to begin using binoculars to view the heavens. Binoculars are wonderful for wide, or spread-out objects. In fact, most people use binoculars in conjunction with their telescopes. I like to locate hard-to-find objects first with my binoculars and then view them with my telescope.

With the possible exception of opera glasses-style binoculars, any old set of binoculars will work for stargazing. Most full-size binoculars can do the trick for amateur observers. Of these, 10 X 50 is the best choice for the casual astronomer. These numbers, by the way, refer first to magnification and second, to field of view. The larger the second number, the greater the field of view.

When stargazing with binoculars, it helps to steady them by sitting in a folding chair and bracing your elbows on your hips or even on the arm of the chair. This helps to cut down on wobble. It is nearly impossible to hold binoculars steady when standing up. That is, unless you use IS, or image-stabilized binoculars.

These IS binoculars use electronic gyroscopes to hold an image solidly with no shake or wobble. Just focus on the object you wish to view and then hold down a button and the IS feature will kick in. People trying these for the first time are always amazed at the difference between regular binoculars and IS binoculars. In fact, IS binoculars impart the effect of an increase in magnification. The steadier the picture, the better you can see fine details.

Such binoculars are pricey, but they offer the best and steadiest view possible. Besides that, they are good when viewing terrestrial objects from boats or motor vehicles. And for bird-watching, nothing beats them.

My personal IS binoculars, a 10 X 30 set made by Canon, are worth every penny I paid for them. Some people use their IS binoculars as much as they do their telescopes because binoculars need no lengthy setup and are ideal for checking out the sky when time is limited. Just remove the lens caps and begin viewing.

If all you have, however, is an old set of binoculars stowed away in the closet, by all means use them. Any binoculars are better than no binoculars.

3. Tricks of the trade

Some little things will help you to see better when stargazing. First, it pays, if possible, to let your eyes adapt to darkness by staying outside for 20 minutes before beginning your serious viewing.

And if you need to read your planisphere or sky chart, make sure to use a red light. Red light does not harm night vision. You can buy special astronomy red lights, but the simplest way is to just take a regular flashlight and place some red cellophane over the lens.

Sometimes you know you are viewing the object you seek, but cannot see it clearly. This happens, for instance, when viewing double stars, stars that are either bound together by gravity or stars that are not at all close together but appear that way from our point of view. These are called optical doubles.

The way to make a reluctant twin to a brighter star suddenly stand out is to look at it with averted vision, that is, from the periphery of your eye, rather than viewing it straight-on. It helps to blink once in a while, too. This helps to steady your eye’s focus.

4. Telescopes

Telescopes come in several types: reflectors, refractors, Cassegrain reflectors and Catadioptric telescopes. The easiest to use are refractors, but they are the most expensive per inch of aperture. I use a 4-inch refractor made by Explore Scientific, and the ease of setting up makes it the best go-to scope available.

However, the best bang for the buck award goes to Newtonian reflectors. These use mirrors to bounce an image into the eyepiece. It is possible to get a decent-quality tabletop reflector for around $100. And, of course, reflectors range in size from 4-inch models all the way up to 18-inch behemoths. For beginners, a 4-inch or 6-inch reflector will give plenty of viewing pleasure for years to come.

5. Upcoming events

July sees many interesting chances for stargazers. First, for early risers, the Pleiades, the famous star cluster also used as the emblem for Subaru cars (Subaru means "Pleiades" in Japanese), are halfway up the eastern sky about 45 minutes before sunrise.

Also, the planet Venus shines brightly below and to the left (east) of the Pleiades.

Then, at sunset, on the nights of July 24-25, Mercury shines a bit below and to the right (west) of the crescent moon.

And on July 28, the gas giant planet Jupiter, along with its several satellites, sits just below the waxing moon. Look to the west-southwest one hour after sunset.

The moon itself makes a suitable target as well. Just remember that the best lunar viewing occurs during the crescent stage. Then, images around the terminator, or line of darkness, are stark and contrasty.

Stargazers like company, and many come together for the Acadia Night Sky Festival. For more info on this annual event, visit acadianightskyfestival.com.

For now, then, happy stargazing and clear skies to you.

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