ASTRONOMY STAR CHART HOW TO

Still cooler are orange and, finally, red stars. Slightly cooler stars appear white, followed by yellow stars (like the Sun). The hottest stars glow with a bluish tinge and can be up to five times the Sun's surface temperature. Under a dark sky, the brightest stars show hints of color. Many of these are too dim to see with the naked eye, but the ones on our map do appear nice with binoculars or a small telescope. Next to the magnitude scale are the symbols we use for deep-sky objects. A star of magnitude 0.0 appears 100 times brighter than a star of magnitude 5.0.

In keeping with ancient tradition, the fainter a star, the higher its magnitude. We show the scale for our map at the lower left corner. Astronomers measure a star's brightness on what's called the magnitude scale. On our map, we show brighter stars as bigger circles. But a map with nothing but small points on it wouldn't help much. In April, only Saturn appears in the late-evening sky.Īll stars appear as points of light to the naked eye. All the solar system's planets lie near the ecliptic, so this is the area to look for our celestial neighbors. Of course, the Sun is not out at night, but the ecliptic still serves a useful function. The brownish line you see curving from southeast to northwest represents the ecliptic - the apparent path of the Sun across our sky. The exact times appear at the top left of the map, but the sky doesn't change a lot within an hour or two of these times. Each month's map depicts the sky in late evening, after twilight has faded completely. And the map gives a good approximation of the sky from as far north as 50° latitude and as far south as 20°. We plot the stars on the StarDome as they appear from 35° north latitude, so the map works well if you live between 25° and 45°. To find the other bright stars and constellations scattered across April's evening sky, simply turn the map to match the direction you're facing. Here you'll see the large constellation Ursa Major, with its group of seven bright stars known as the Big Dipper. Go back to Leo and Virgo, then crane your neck and look straight overhead. This arrangement looks odd when you look down on the map, but it's perfectly logical as you look up. Note that as you face south with the map overhead, east lies to your left and west to your right. The planet Saturn currently lies in southern Leo, below it as you look up.

More than halfway up in the sky, you'll see two of spring's bright constellations: Leo and Virgo.

Turn the map 90° counterclockwise and place the yellow 'S' at the bottom. Next, shift your gaze to the southern sky. Only part of Orion remains visible, while the bright star Procyon and Gemini's twin stars, Castor and Pollux, appear prominent higher in the west. Late on April evenings, you'll see the stars of winter descending toward the horizon. Find the big yellow 'W' on the map's right side, and orient it so the 'W' lies at the bottom as you look due west.

ASTRONOMY STAR CHART HOW TO

I've mounted this map on cardboard to make it easier for you to see how to use it.īecause the sky lies overhead, we designed the map to be held above your head. Open it to the center, and you'll see the fold-out map we call the StarDome. I happen to have the April 2009 issue with me. The first question most beginners ask is: 'How do I find my way around the sky?' The easiest place to start is with an all-sky map, like the one you'll find in the center of every issue of Astronomy magazine.

Astronomy star chart