Now Available in E-Book and Paperback! This series of stargazing lessons will walk you through many of the constellations visible in the northern hemisphere. Once you have mastered these, you'll be ready to look at any star chart and learn the rest on your own. For simplicity, the stars in my diagrams are not shown with relative brightness taken into account. When you see the stars in the sky, some will be bright and clear, and some will be very faint. For best results, try to do your stargazing as far away from city lights as you can. Turn off porch lights and other night-vision-destroyers (or block them with your hand as you look at the sky). Choose moonless nights for stargazing. As it turns out, you have to start somewhere, so there's a prerequisite for this course: find the Big Dipper yourself. If you don't already know it when you see it in the sky, have someone point it out to you. If you're in the northern hemisphere, it should always be above the horizon (as long as you're not too close to tall buildings, tall mountains, or tall trees), and it serves as a good starting place to orient yourself each night. Become very familiar with the shape of the Big Dipper, and keep working at it until you can always find it, and you're 100% sure that's what you're looking at when you do find it. Once you can do that, you may proceed. The Big Dipper: The Big Dipper is like a giant frying pan in the sky. Technically, it's not a constellation by itself; it's an "asterism." An asterism is simply a commonly recognizable pattern of stars (It's the lower one). The Big Dipper is part of the Great Bear, or Ursa Major. The rest of those stars are sort of below and to the right of the frying pan, but for our purposes, they're not important. You can use the Big Dipper to find other things in the sky, which is why it's such a good place to start. The Little Dipper and North Star: The two stars on the front end of the frying pan part of the Big Dipper are called "pointer stars." They point to the North Star, or Polaris. If you take the distance between those stars and extend the line out 5 times that distance, you'll arrive at the North Star. The North Star is at the tip of the handle of the Little Dipper, or Ursa Minor. The North Star is bright, as are the two stars at the end of the pan of the Little Dipper. The rest are tricky to see unless it's really dark. Why do we care about Polaris? The North Star, Polaris, is not a particularly bright star compared to many other stars. The reason we pay attention to it is because it never moves. It is located directly above the North Pole. As the Earth spins on its axis, the sky appears to rotate (the same way that if you look straight up at the ceiling in your living room while spinning around really fast, the room looks like it's spinning, but it's really you - the North Star is the spot on the ceiling right above you). This diagram shows how the Big Dipper and Little Dipper move throughout the course of the night (and day), but the one star at the tip of the handle of the Little Dipper, Polaris, remains in the same spot the whole time. Each night as you begin to stargaze, the stars will be in a slightly different location than the night before (unless you start precisely 4 minutes earlier each night, but pretty soon you'll run into daylight). Finding the Big Dipper, and using that to find the North Star, will help you find your way around the rest of the sky. This photograph was taken using a tripod with a 15 minute exposure. During the time the shutter was open, the Earth rotated enough to see a difference in the position of the stars. Polaris appears as a single dot (right next to that tree, almost like it's being cradled in the branches), other stars close to Polaris advanced just a little bit, and stars farther away show a great deal of motion. Notice that some of the stars appear to be different colors than others. I'll point out notable blue and red stars along the way as we learn more constellations. This photograph is called "Continuing Mission," and is available for sale in many formats here. Bonus Nerdy Bits: The middle star in the handle of the Big Dipper is actually 2 stars (well, if you want to get really technical, it's 6 stars). The stars are named Alcor and Mizar, and are sometimes referred to as the "horse and rider." If you look really carefully and have near-normal eyesight, you can actually see two stars very close together. It also helps if it's (once again) a really dark, moonless night. 12/26/2011 05:17:35 am
beautiful picture! my son is just getting into stars, very helpful as we look up together :) Comments are closed.
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