Savoring the Summer Triangle

Star light, star bright, First star I see tonight . . .

If you go out into a wide-open field about 20 minutes after sunset this summer, the first "star" you'll see won't be a star at all -- it'll be the planet Jupiter, shining fairly low in the south (June and July) or south-west (August and September).

So turn left, toward the eastern sky, where you'll find the star Vega coming into view well above the horizon. For me, Vega is the "first light" of summer, a bright star that stays in view from dusk to dawn at mid-northern latitudes throughout the warmest months. And if you look in that part of the sky about 45 minutes after sunset, what you'll see is not just one star but three. The stellar trio before you forms a triangle that's impressively large -- two of its sides are quite a bit longer than the entire Big Dipper. Yet the whole scene just fits within one wide-eyed-with-wonder field of view.

You're gazing at the Summer Triangle, one of the most familiar star patterns in all the world.

This broad triad burns dramatically in your still-bright dusk sky. Vega, its dominant star, shines on top. Altair, its second-brightest jewel, is to the lower right. Deneb lies to the lower left. But as twilight starts to fade, you begin to make out quite a few fainter stars coming into view in and around the Triangle. Look for a flanking sparkler to either side of Altair, which together with it form an eye-catching short, straight row. And to their left, a large and obvious cross of lesser stars juts from Deneb almost like a big-handled knife driven nearly all the way through the Triangle.

What's visible at this stage of twilight is the most that you're likely to notice by eye while looking through unusually thick summer haze, full moonlight, or big-city light pollution. Even this much detail is fascinating in itself -- and valuable as a guide to the many other wonders that can be seen using binoculars or a telescope.

But imagine that you are in a dark country location. When full darkness finally envelops the land, your amazement fills you to the brim. The Triangle now seems to be encrusted and spangled with glittering stars. But most awesome is the way an intricately detailed band of soft radiance -- the Milky Way -- that brightens dramatically within the Triangle. This "star cloud." one of the Milky Way's most concentrated glows, shines right beside the black start of its greatest cleft of darkness.

Each of these levels of visual penetration -- bright twilight sky, urban or moonlit sky, and dark country sky -- has its attractions. First, we'll visit each of the three brilliant stars of the Triangle itself. Next, we'll tour some of the constellations that enrich this region. Last, we'll explore a few of the more intricate treasures of the Triangle -- ones that require a dark sky or at least modest optical aid.

-- Continued on Page 2

© 2006 Reprinted with permission from Sky Publishing Corp.