For most of us in the United States, by now evenings are beginning to have a bit of a chill in the air. That’s thrilling for a couple of reasons, especially for those of us residing in the Deep South: not only does it mean no more wiping sweat from the brow a full hour after sunset, swatting mosquitoes and gnats, but also that dusk is occurring about a minute earlier with each successive night (which of course means more stargazing time!).
There’s good and bad associated with that. Scorpio’s beginning to have a pronounced downward tilt, hanging precariously low in the Southwestern sky after it gets fully dark. Remember that the scorpion hosts the sun during November, so its remaining time on display for 2014 is short. It’s silly, but as much as I cherish Fall, I hate to see these Summer Attractions vanish (Scorpio will be back, however, its singular baleful red eye of Antares hanging low in the pre-dawn Southeastern sky, late February).
Take a quick tour of the aforementioned Sagittarius points of interest mentioned in my previous, recent blog entries…then it’s time to move along. As one “group” of stellar highlights take a dive, another group is coming up: again the night sky is, for my seasoned orbs, the ultimate i-max theater. the show is constantly, albeit incrementally, changing from night to night.
Let’s return to the group of previously overhead constellations that are now positioned high in the western portion of the sky: Cygnus, Aquila and Lyra. If you want to revisit the attractions I last mentioned (The Veil and North American Nebulae), by all means take a quick gander at both. They’re positioned about as nicely as they ever are right now. By that I mean where you can comfortably gaze upward, through a telescope, without unduly craning your neck!
Next up: slew your scope toward the constellation Lyra (again, I think of it as the “shopping cart”, because that’s exactly what it looks like). Focus on the space between the two stars that define the “front” end of the “cart”. This is where a nice, two or three degree field of view comes in handy, as the object we’re going to hunt down next is a tiny one: the Ring Nebula, or M57, its official designator.
This photo is closer to what you can expect to see through a backyard telescope, albeit a “smoky grey” image, versus this color one. Someone might ask, at this juncture, “Then why bother getting out and going through all the hassle, if a black and white image is all we can expect?” I can only answer in that NO photograph can convey the “3D” aspect of gazing through an eyepiece…you have to experience this to appreciate it. Also, you can slew around the object to gain perspective (something no photo can do).
Anyway, back to The Ring: this little guy is a planetary nebula, due to its generally round appearance. Higher magnification actually shows it to be oval-shaped, a “smoky”doughnut” against a starry backdrop. The ring shape is more obvious if you employ a technique known as peripheral, or averted, vision. Look away from the nebula, focusing on an adjacent star, and you’ll more easily discern the ring shape.
Again, the common question is always, “Why aren’t these objects in color, like the photographs?” Cameras doing time exposures can gather SO much more light than the color receptors in the human eyeball! That said, an enormous aperture lens or mirror will begin to reveal faint green and even fainter pink hues in the brighter, nearby nebulae…but who can afford one of those observatory-sized instruments, much less have the shelter required to house it?
More to follow…clear skies!