7:30 p.m. 14 July 2007 PDT (2007–07–15–0230 UT)
It's been a long time since I did some serious observing with Opus, my C5+. Having warmed up a couple of weeks ago with a pair of familiar objects (M4 and M51) back home, I decided to get back into the swing of things with a trip to Lockwood, the dark sky site of the Los Angeles Astronomical Society.
I pulled into the site's parking lot while it was still light out, but only barely. I only had time to set up and wolf down a quick pastrami sandwich before it was time for the group to get together for general instructions. Nothing terribly new being said there, but they don't like anyone to sit these things out. I did contribute a few bucks to the general fund and went back to my pad.
It was still twilight, and there was still some serious clouds to the south, which contributed to somewhat lower turnout; a few of the neighboring observers mentioned that June had brought out maybe 50 observers—twice what had come out this month. So rather than get at the eyepiece right away, I took out my IS binoculars and took a loook at Venus and Saturn, close by Regulus.
There is something engaging about seeing Saturn by binoculars that just barely show the rings, almost as though you were almost gleaning them by the unaided eye. And the gold-on-gold of Saturn against the fading twilight is appealing, too. Of course there is no question of seeing the Cassini Division, or the faint striations of the cloud bands, or anything like that, but yet, there's something about it that's quite different from seeing it in a telescope. Maybe it's that in a scope, you almost feel as though you're in a spaceship lingering just a few million miles off, whereas with the binoculars, you get a visceral feel for just how small even such a giant world is in our sky.
After a few minutes, the southern sky was still fairly cloudy, but there was a break in the clouds for the only object bright enough to make much of an impression to the unaided eye: Jupiter. Now I am not generally impressed with the steadiness of the skies at Lockwood. They are of course dark—reasonably dark for barely 60 miles outside of Los Angeles—but the seeing there has historically been fairly forgettable. But one of the nearby observers was watching Jupiter through his 8-inch SCT, and rather enjoying the view, so I decided to walk over and have a look.
Jupiter did look reasonably detailed, but not extraordinarily so. I didn't think the seeing was very good in any absolute sense, though it was certainly much better than was usual for Lockwood. Still, there was not yet much else to look at in the sky (other than for the challenge of seeing them while twilight was still bright), so I too pointed my scope at the largest planet.
Well, as twilight deepened, the seeing just got better and better, until after a half an hour or so, it truly was very good in an absolute sense. Not the best I had ever experienced with Opus—I remember one evening on the front lawn at Griffith Observatory, before it was renovated, when the atmosphere seemed to magically part before us—but it was still certainly very impressive. And since I had not bothered to look at Jupiter all season with a telescope (binoculars yes, but no scope), I had no idea what had happened since my last gander.
First and foremost, the equatorial band (EB) had apparently split in two; at least, the part visible to us had. I'm sure this comes as no surprise to many of you, but it was totally new to me. Even so, each half was fairly broad, broader than I had seen the entire band on most occasions. The northern hemisphere was more or less ordinary looking, with a pair of festoons perhaps 30 degrees or so of longitude on either side of the central meridian.
But the southern hemisphere was another story entirely. The south equatorial belt (SEB) was weak looking, pale and thin. A shadow transit was at the limb—Ganymede. Someone thought it might have been Ganymede itself, but no, the black spot was a bit too dark and noticeably elongated, whereas the satellite itself would have been round. And PleiadAtlas showed the satellite to have been a Jovian radius off the limb altogether. The final clincher was all four satellites in view, of course!
Even beneath the SEB there was plenty of detail. What normally appears as a vague, nebulous polar region in a small scope was a swirling mass, waves of faint blue-grey mixed in a sea of ivory. There was a nodule near the preceding edge of the SEB. I thought at first that it was the Great Red Spot (GRS), but PleiadAtlas showed that to have rotated around to the back side of Jupiter already. Does anyone know what that might have been?
After a while, I figured it was time to take a look at objects that wouldn't look substantially the same back home. I began with one of the objects from my trial run at home, M4. This is a fantastic object for small telescopes, since even a casual glance shows it to be different from other globulars. Even at home, the north-south bar is fairly straightforward to see, and from Lockwood, it was distinct, and began to show some variation in thickness and even texture along its length. One can verify, with an polar-aligned mount, that the bar is not quite north and south, by twiddling the declination knob.
Next up was M22, except that I misidentified it from memory. If anything shows you how rusty I was, that was it. A nice lady and her grandson were out for a test run with his small refractor (a Celestron 60 mm, I think—computerized, but they weren't using the computer) and were asking about nice objects to look at. I pointed it at M22, going northeast from the tip of the teapot of Sagittarius, past a trio of sixth-magnitude stars, to a nice fuzzy patch, but I called it M25. No sooner had I said it when I had a misgiving about its identity, but I didn't say anything further. A quick check with PleiadAtlas a few moments later revealed my error. (M25 is, in fact, an open cluster in the same general region of the sky, but not particularly near M22.)
Incidentally, the last time I was at Lockwood, I was still using a Palm m505, the next generation of my original Palm Vx. Both of those were monochrome devices, which I darkened to acceptable levels with neutral density sheeting (3 or 4 stops, I think). But the Treo 680 I use now has a color display. PleiadAtlas has an option to turn the color display red, so I used that, but unfortunately, the keyboard is also lit up, and I had no sheeting for that. So before I head back up to Lockwood the next time, I have to figure out a solution for that. For the rest of the night, I resorted to the old-fashioned method of atlases and books, plus the red flashlight.
For a while after the M25 impostor, I skimmed through the Barnard nebulae in Sagittarius. I wasn't aiming at anything in particular, since this is something I do more typically with the 10-inch dob sporting the 55 mm Plossl; I just wanted to gain a feel for the place. I did try hunting down one thing, which I know by appearance but not by name. One of the LAAS oldtimers who doesn't observe much more with the group had directed me toward what he nicknamed the Inverse Ring Nebula. It is a dark nebula in the shape of a donut, and it does rather resemble a photo-negative version of the more famous Ring Nebula (M57). He showed me where it was, and then I vaguely surprised him by being able to find it again in a few seconds—which makes my inability to find it in the years since all the more frustrating. No one else at the site, experienced or otherwise, could figure out what I was searching for, either. (Nonetheless, I'm not making this up!) If this description sounds familiar at all to anyone, please let me know what it is I'm looking for.
After some time, I gave up and began looking for easier stuff. M8 and M20 are far less frustrating than hard-to-find dark nebulae through a small scope; in fact, while I was hunting for the Dark Donut, I ran across M20 by accident on no fewer than three occasions. Even from my bright backyard, M8 is a good sight, but M20 suffers, of course. From Lockwood, it is a delicate-looking thing, nothing like through the 10-inch, but still showing the three petals that give it its nickname, the Trifid.
With that, it was time to try for some more serious stuff. First up was vdB 126, a mixture of dark and reflection nebulae surrounding an eighth-magnitude star in Vulpecula. Perhaps a few arcminutes across, it is described as a challenge in a 6-inch from suburban skies, but even from dark skies, I could make out no significant sign of it through the 5-inch.
Matters were improved, sort of, on my next target, Sharpless 2-82, a combination of emission and reflection nebulae. I did get a feeling that there was a glow to the side of the brightest star (not the star that lights up the reflection nebula), but to be honest, I could also get that feeling about half a dozen other stars in the field of view. It's important to confirm observations that you particularly want to make! The UltraBlock (Orion's narrowband filter) did seem to make the target glow somewhat more prominent, relative to the others, but I could not chalk it up as definitely seen. Probably seen, though.
IC 4996 is a small, sparsely-populated open cluster in Cygnus. It's mostly made up of several ninth to eleventh-magnitude stars, with maybe a layer or so of dimmer stars "underneath." Through the C5+, it's pretty underwhelming, if at least distinctly visible. The undercurrent of dimmer stars is not strongly detectable in such a small scope, since such dimmer stars are visible everywhere throughout Cygnus, and they are only somewhat denser within IC 4996 (if at all).
My last serious telescopic object was NGC 6871, another open cluster in Cygnus. Fairly easily seen, and even though it's also fairly sparse, it does at least have an appealing three-dimensional look to it, almost as though the stars were highlighting the corners of some celestial polyhedron. The brightest star of NGC 6871 is fifth-magnitude 27 Cygni off to the north, not a true member, as it's an orangish K0 only about 80 light-years distant, whereas NGC 6871 is a few dozen times further.
I said my last serious target was NGC 6871, but not my last target. I did aim Opus at NGC 7000, the North America Nebula, though not with any particular expectation of seeing it (and I didn't). Nor did I find anyone with a proper filter to use, although I did not try using the UltraBlock, as I should have. Next time, perhaps.
It was about one in the morning by this time, so I packed up the scope and put it back in the car. I must remember to either not turn on the car lock next time (the beep bathed the field in a red glow) or figure out a way to keep it from lighting up when I unlock it. I took the binoculars out one last time to look at M31 rising in the east; M32 and M110 were easily seen with it, of course. Something to remember for the next time I come out to Lockwood—in September, I hope.
Copyright (c) 2007 Brian Tung