If you’re like most people, you have binoculars lying around in a closet somewhere. Quite likely, you’ve never tried pointing them skyward at night.
Yet binoculars are such marvelous instruments for stargazing that no observer — whether beginner or advanced — should ever be without them! They’re much easier to use than telescopes, thanks to their rapid pointing capability, wide fields of view, and the fact that they show things right-side up, matching what you see with your unaided eyes. They also allow you to observe through both eyes at once. This is much more comfortable than squinting through a telescope with one eye, and it gives some people an amazing illusion of depth perception.
Nothing beats grabbing binoculars and running outside for a quick look when time, freezing tempera-tures, or passing clouds make setting up a telescope impractical. They’re so convenient and enjoyable that I’ve used them for a quarter of the 20,000 hours of stargazing time that I’ve logged.
These humble instruments provide wonderful views of celestial showpieces from our solar system to dis-tant galaxies. Indeed, some objects actually look better in binoculars than through telescopes. Among these are constellations and asterisms, big open star clusters, and the grandest galaxy of them all: our own Milky Way!
Stars, Constellations, and Asterisms
Many of the brightest stars display lovely tints even to the unaided eye, and star colors are greatly en-hanced by binoculars. Compare, for instance, the sapphire-white radiance of Vega overhead with the warm ruddy glow of Antares setting low in the west at dusk. Binoculars also show colors in many fainter stars that appear unremarkable when viewed without optical aid. One striking example is Mu Cephei , also called Herschel’s Garnet Star, whose deep orange hue stands out from the blue-white of the surrounding suns. Mu is also a variable star. Observing the changing brightness of such restless suns for both pleasure and science is a vast subject unto itself.
Many stars turn out to be pairs of close-space suns when viewed through binoculars. Several of these double stars share the same field of view with dazzling blue-white Vega. The widest is Delta Lyrae , a striking reddish-orange star with a dimmer blue-green companion. Epsilon Lyrae is a pair of matched white suns about a third as far from each other as the components of Delta. It’s also called the Double-Double, because both of its components turn out to be close pairs when viewed through telescopes at high magnifications. A third, much tighter pair is Zeta Lyrae — an unequal combo with a definite color con-trast. Zeta may prove hard to split unless you can contrive some way to hold your binoculars perfectly still.
Even more challenging than Zeta is the famed Albireo, a lovely combination of topaz and sapphire suns. Although generally regarded as a telescopic double star, it can be resolved in steadily-held 10x binoculars.
Most constellations are so big that they’re best viewed with the unaided eye, but the autumn sky contains several compact groups that fit into one or two fields of view through binoculars. Foremost among these are Sagitta and Delphinus.
Asterisms are eye-catching groupings of physically unrelated stars. They range in size from the gigantic, sky-spanning Summer Triangle and Winter Hexagon to tiny formations visible only through telescopes. One of the most striking is the Coathanger, also known as Brocchi’s Cluster, a line of six stars with a four-star hook extending down from its middle. This amazing asterism is a perfect match for binoculars, being too big to fit in most telescopes’ fields of view but just a little too small and faint for most people to see clearly without optical aid.
Star Clusters and Associations
Open clusters are loose collections of stars held together by their mutual gravity. Like the Coathanger as-terism, several of these are so large that they look better in binoculars than through a telescope. Notable among them is
IC 4665 in the constellation Ophiuchus, sometimes called the Summer Beehive because of its similarity to the even larger and splashier Beehive Cluster of spring. Much more compact is the
Wild Duck Cluster (Messier 11), which packs more than 500 suns into a circle of sky less than half the diameter of the Moon. Although most of these stars merge into a blur in typical binoculars, there’s a bright star at its glittering core that does shine through.
-- Continued on Page 2© 2006 Reprinted with permission from Sky Publishing Corp.
