Summer is pretty much upon us, heralding warm, albeit short, nights for stargazers. For some of us amateur astronomers, it’s a welcome sabbatical from those frigid winter nights; for others, it’s the harbinger of muggy, insect-infested evenings, with stargazing that begins too late to make it practical on a weeknight ( on or close to the Summer Solstice, June 22nd, it doesn’t get fully dark till about 9:00 p.m.). The onset of Summer-a break from academia for some, and/or a chance to work for others-is also the season in which the richest region of our sky is rising late at night: the constellations of Sagittarius and Scorpio.
It’s hard to overstate the majesty of this section of night sky. From a dark site, totally removed from so much as a stray mercury or sodium vapor light, the vista is stunning. Superlatives fail. With the aforementioned two constellations cresting above our southern horizon, the Milky Way stretches upward, weaving its way predominantly through Sagittarius, like a gossamer curtain…extending through the constellation of Cygnus, directly overhead. If you have a simple pair of binoculars and a comfortable lawn chair, prepare to be stunned. Sweeping back and forth, up and down this “curtain” will blow your mind, especially for the first time.
If you have a telescope, there are more deep-sky denizens in these two constellations-especially Sagittarius-than four or five other constellations combined. The Lagoon Nebula (M8) is visible to the naked eye, conveniently positioned so as to suggest a steam vapor emanating from the “teapot” group of stars constituting Sagittarius. A telescope reveals what upon first glance looks like a small group of stars, with a smudgy “patch” of luminosity next to it. Another “smudge” a mere two degrees away is the Trifid Nebula (M20). Moving a few degrees East and Up, you’ll likely run across the globular cluster M22 (sorry; no ‘nickname’ this time): it’s one of the finest visible from our planet. Try, as you take this star-studded “snowball” in, to imagine what the night sky would look like from a planet orbiting any star within that group! These vanguard objects in Sagittarius are a treat through any small scope, but if you have access to a larger instrument, you’ll see more detail. More on that later.
Don’t expect these guys to look anything like those Hubble/Nat’l Geographic color photos, though. With the exception of planets, virtually all celestial objects are too faint to adequately stimulate the color receptors in our eyes. Think of the old adage “At Night, All Cats Are Grey”…some may be thinking, Then why do I want to cultivate a hobby, looking at a black and white universe? Because the three-dimensional aspect of gazing through a telescope-or a good pair of binoculars-cannot be conveyed with a picture. Or the “context”: with binoculars, typically yielding a five-degree field of view, you can see the surrounding “neighborhood” of stars, some of which make interesting pairings-called double stars-or even “mini-constellations”.
If you’ve followed me this far, we’re just getting started. I would heartily recommend purchasing a star finder. It’s one of those wheel-shaped gizmos that lets you “dial up” the show, for whatever time of year you’re venturing out. Please take it from an old purist: learn the constellations! Forget that nifty telescope with an onboard computer…spend the same money on one without the electronic Whistles & Bells, but with a bigger lens or mirror instead.
More on the types of telescopes next time…