“Hopping”Into Astronomy

Winter is in full-swing this week, with fresh snowfalls (not to mention temperature falls). And though this snowy wonderland brings a flurry of activity during the daytime, with school groups coming in almost every day, I’d like to instead dedicate this post to the less-frequently seen beauty of River Bend—that is, what we can only see after dusk. And even though we’ve passed the Winter Solstice, the sun is still setting relatively early, around 5:00 pm, which is good news for those of us who look forward each evening to having the opportunity to be astronomers. I find my own eyes wandering skyward as well, as the light starts to vanish at the end of the day, because no matter how many times I see it, I never get tired of a sky full of stars. But to the amateur astronomer, learning where to start can be a daunting task. With countless telescopes on the market, weighty textbooks filled with complicated diagrams and star charts, not to mention the sheer number of celestial objects to be viewed, it’s enough to make anyone want to quit before they’ve even started. This blog post is meant to serve as a beginner’s guide to astronomy. Whether you’ve taken a few courses in school, or whether you’re just starting to wonder about the night sky, this guide will be a simple tool to take away some of the complications and confusion of amateur astronomy.

The first step to learning about the stars is to not buy a telescope. This is so important and so misunderstood, that it’s worth saying again: do not begin your interest in astronomy with buying a telescope. This is perhaps the fastest way to kill the hobby, as telescopes can be expensive, and are not simple tools to use, even with experience. Even the ones advertised for beginners which promise easy-use, can’t be used for much more than to look at the moon. If you still want to be able to have a “close up” of celestial objects, instead purchase or borrow a pair of binoculars, which are far less expensive, and far easier to use. Truly though, the only tool you need to study and enjoy the night sky are your eyes and a willingness to observe. Couple this with a little bit of study, and you’re well on your way to opening up the entire cosmos. But for the purpose of this blog, we’ll start small, or rather, we’ll start close.

When you look up into the night sky, what you are viewing is a portion of our home galaxy, the Milky Way. On average, without the aid of a telescope or binoculars, you may see up to 2000 stars, although the galaxy is believed to have over 100 billion stars. We are limited on what we can see because of several reasons: Many stars are on the other side of the Earth, some stars are too dim or too far away to be visible, and some may be blocked from sight by other planets or other stars. In fact, some of the difficulty lies in the fact that Earth is positioned within the Milky Way galaxy. If we were outside it, we could view the entirety of the galaxy and all of its stars, but being within it means that we can only ever see portions of it at a time. For those same reasons, the stars that we see with the unaided eye, are only stars within the Milky Way, and they are generally the closest ones as well.

galaxy
Photo credit: google images

For the amateur astronomer however, 2000 stars is a great place to start—It’s where our ancestors began and all civilizations before us began as well. These are the stars that make up constellations, and are the easiest and most fun to explore.

In the Northern Hemisphere, the easiest constellations to spot are known as “circumpolar constellations”. These groupings of stars are situated above Earth’s northern axis, and therefore can be seen in the night sky year round, unlike other constellations which appear to rise above and set below the horizon.  Probably the most famous of the circumpolar constellations is the constellation known as Ursa Major, the Big Bear—which includes the Big Dipper.

big-dipper
Above: throughout the year, the Big Dipper is always visible, but just appears to move in a circle.
Photo credit: google images

The Big Dipper is also the most famous example of an exercise known as “star hopping”. In star hopping, the viewer takes stars that he or she is familiar with, and uses them to find stars and constellations they are less familiar with. In this way, your knowledge can easily be expanded across the sky! To locate the Big Dipper, start by looking North. If you are not sure which direction North is, start by picking the darkest section of sky. At the time of this post, the Big Dipper is located relatively low near the horizon, so begin your search there, turning in a slow circle and search for a bright grouping of stars. In the winter, the Big Dipper appears to be standing on the end of its handle, with the bucket pointing straight up. To begin star hopping, once you find the Big Dipper, locate the two end stars of the bucket (known as pointer stars) and follow them towards the next brightest star, as shown in the above image. In this way, you have successfully “hopped” to the North Star, Polaris, and also the constellation Ursa Minor (Little Dipper).  Polaris is the last star in the “handle” of the Little Dipper. After acquainting yourself with which direction is North, this will allow you to locate even more constellations.

Another easy circumpolar constellation to spot is Cassiopeia the Queen. To star hop to this constellation, continue following the path of the pointer stars from the Big Dipper, past Polaris the North Star, and the next brightest star along that curve is Cih, the central star in the w-shaped constellation Cassiopeia.

cass
Above: Starting with the Big Dipper, follow the pointer stars up to Polaris, and finally up to the W of Cassiopeia.
Photo credit: Stellarium

In addition to the Circumpolar constellations, there are easy to spot groupings of stars that are most prominent in certain seasons. In the Winter, this includes the constellations Orion, Canis Major, Canis Minor, Taurus, and Gemini. The easiest of these constellations to find, is the constellation of Orion, the hunter. It is also from this constellation that you may star hop to several others listed previously. To find Orion in the night sky, look to the Southeast, midway between the horizon and directly overhead. The most prominent section of Orion is the three stars that make up his belt. These stars are grouped closely together in a straight line, while the remainder of the constellation forms something similar to an hourglass around them.

To star hop to two other prominent winter constellations, follow the line of Orion’s belt up towards the red star Aldebran, which is the left eye in the constellation Taurus the Bull. In Mythology, Orion is often depicted as fighting the Bull. Similarly, follow the line of Orion’s belt down towards the bright star Sirius, also known as the Dog Star. Sirius is the brightest star in the night sky, and is also therefore the brightest star in the constellation Canis Major (in mythology often depicted as one of Orion’s hunting dogs).

aldebranPhoto credit: Stellarium

siriusPhoto credit: Stellarium

By following these guidelines, and expanding on knowledge you already have, it soon becomes easy to begin tracing many well-known constellations. After you are familiar with the easier constellations, consider getting some simple star charts (planispheres) in order to find more difficult stars and constellations.

Winter is a great time to view the night sky, and River Bend offers a wonderful view from the prairie loop trail and the overlook trail. And if star gazing is something you’d like to learn more about, attend River Bend’s upcoming Winter Fest ( http://www.rbnc.org/winterfest/ )—new this year will be presentations on star gazing, with a chance to put your skills to the test! Also coming up will be a traveling celestial show to be hosted at River Bend on January 27th (http://www.southernminn.com/faribault_daily_news/community/article_6535d35f-d6b3-5a89-919b-a981a67de6bf.html ).

 

Have other tips and tricks for finding stars and constellations? Please share them in a comment!

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