I went to Fremont Peak State Park, near San Juan Bautista, California, on the evening of May 9, 1997, and again on May 10. Seeing was good, the Moon set early enough to leave plenty of time for deep-sky work, and the fog rolled in on the lowlands sufficiently to dim the lights of many towns and cities. These were fine nights
On both occasions, I took along my 98 mm Brandon refractor (yes, 98 mm), but on Friday, I was sufficiently successful at mooching telescope time that I did not bother to set it up. I arrived a bit after the end of twilight, and learned that several people had already tried to search for IC 4617, the "other" companion galaxy to M13, and had failed.
M13's better-known "companion" is NGC 6207, about 20 arc minutes northeast; it is easy in a four-inch telescope in dark sky. IC 4617 is about half way out to NGC 6207, and is much tougher. Unless you have a rather large telescope, or deeper charts than most of us use, just the position won't help you find it, because it is small, faint, and close to a couple of stars of comparable brightness.
The galaxy does show on the picture of M13 that is on page 979 of Robert Burnham's _Celestial_Handbook_ -- that's in Volume II -- but it is not obvious. As near as I can measure, its tiny image lies 38 mm down from the top of the picture (that's the border of the picture, not the edge of the page), and 47 mm in from the left (ditto). The image is a narrow streak about 2 mm long, trending top-left to bottom-right, and is just off the lower right star of a 5 mm long parallelogram of stars that trends similarly. I have two copies of Burnham -- one hard-bound and one paperback. Differences in printing result in different appearances of the galaxy on the two pictures, and in positions that differ by almost 1 mm. It's just barely there on the picture -- if you are looking at Burnham and say "that can't be it", you've got it.
Note also that the picture in Burnham was taken with a plate whose spectral sensitivity is different from that of the eye -- the relative brightness of many of the stars photographed seemed different to me when looking through the telescope than on the picture, and also, the galaxy seemed relatively brighter to my eye, looking through the telescope, than on the picture. A good thing it was, for otherwise I would not have seen it.
[Here is a DSS image with M13 in the lower right NGC 6207 in the upper left and IC 4617 just right of center - Bill]
But I am getting ahead of myself. What I did was ask a friend if we could try for IC 4617 through his 12-inch Meade LX200. He remarked that he had already tried, and had no luck, but would try again later, when the three-day Moon had set and Hercules was higher in the sky. But he had used only a low magnification, so I persuaded him to let me try with some shorter focal-length eyepieces.
I star-hopped from NGC 6207 to the little parallelogram, increased magnification again, and stared. At 341x, the tiny blur was barely detectable -- I could see it intermittently with averted vision. I said as much to my friend, who unhappily could not see it at all. Another observer, who had joined us by then, was half-convinced she could see the galaxy.
I wandered off in search of more aperture. In a 14.5 inch Newtonian 50 yards away, the view was much better -- a little aperture helped a lot. At 107x I could hold NGC 4617 with direct vision, and could see it as a streak. I suspect that all I was seeing in the 12-inch LX200 was the galactic lens, the elongation had not been nearly so obvious.
I went back to the Meade, and reported my success to my friends. They of course immediately wanted to go off and try larger apertures themselves. As they were walking away, I asked if I could borrow the use of the 12-inch till they got back. "Sure." And so -- since IC 4617 was indeed a rather tough target, and there were several large telescopes at the other end of the setup area -- I had the Meade 12-inch all to myself for rather more than half an hour. That's a good trick, I will have to make sure that my future observing programs all include one or two objects that are equally tough and equally interesting.
So, how does this thing work, anyway? I had had cursory instruction from my friend. Let's see -- press "M", "5" and "1" and then "Enter". BRRRRRRT! I had reduced the magnification to 88x. M51 showed several spiral arms, textured and clumpy, and the bridge to its companion, NGC 5195. Not bad, for the Moon still up. "M-1-0-1"... BRRRRRRT! The LX200 sounds like an espresso maker, why didn't I bring coffee? M101 also showed spiral arms, and several rich star clouds or large HII regions. M81 showed its elongated central band and at least one of the two prominent winding spiral arms, for almost half a turn. M82 was lumpy and textured. M94 had a strong central concentration of brightness. M64 showed the "black eye" clearly.
About that time the hand controller developed what we later figured out was a mechanical problem, a stuck switch in the joystick, so that the telescope started trying to drive in increasing azimuth even with the joystick centered. While trying to fix the problem, I managed to change the joystick rate from one appropriate for small corrections to "slew", with the consequence that I could not put the joystick down without the telescope trying rapidly to wind its altitude motor power cord around its drive base and strangle itself. I could not find the power switch because it was dark and my red flashlight was back in my car. I was beginning to fumble for power cords to pull, when fortuitously the telescope's owner returned and rescued me. Naturally, the glitch would not recur for him.
Later in the evening, we used the 12-inch LX200 to look at several other interesting objects: At 154x, NGC 5128 showed its wide, dark central band, and the central stars of M27 (154x) and M57 (341x) were visible -- the former more easily. The LX200 seems to be an entirely serviceable and useful design, but it really does need a spigot where you can draw off all that espresso.
I wandered around to some other telescopes. After moonset, IC 4617 became much easier -- my best view of it of the night came in a 12-inch Newtonian at 180x, in which I could hold the galaxy with direct vision. I suspect the 12-inch LX200 would have done as well, if I had had a chance to try it again. But I could not find the galaxy in either of two six-inch reflectors, at magnifications of 60x and 75x, or in either of two Astro-Physics 180 mm refractors, at 100x and 140x. I suspect it would have been visible in a 10-inch, or perhaps even an eight-inch, in the conditions that obtained with no moon and fog below, but no telescopes of these apertures were handy.
The owners of the big Astro-Physics units were duking it out as to which telescope was better. Both were very new, Roland Christen's latest efforts, but one is f/7 and one f/9, so there was the prospect of greater difference than mere manufacturing variation. Their discussion was getting rather silly when I got there, which I think means that there were no detectable differences in performance, at least, not for visual use. They both looked fine to me.
I had brought an even smaller telescope than my Brandon -- a Meade model 165 50 mm f/12 refractor, with which I have been conducting a Messier survey. I polished off a few more objects -- I am now up to 103. A 50 mm refractor is more than enough to see the entire Messier catalog, and it even shows interesting detail in some -- at 24x, M6, M7 and M8 were all resolved, and the latter showed much nebulosity. I was particularly pleased that the little refractor picked up M55 almost as soon as it had cleared the horizon.
While I was thus engaged, another friend offered me the use of his Astro-Physics 130 while he walked to another area of the Peak. I think he was miffed that I turned him down, in favor of a mere department-store wonder. But his telescope was mounted on another kind of mounting that I am not familiar with, and I had had enough hardware problems for the evening. Besides, Messier surveys are serious business. And what's more, the Meade was advertised as having a lot more magnification than most people use on an AP 130... :-)
I didn't get as much sleep as I would have wished between Friday and Saturday, so when I returned to the Peak on Saturday evening it was only for a short stay. There were lots of people there, so many that when I arrived -- rather late -- the ranger had closed the gate to the most popular setup area, in an effort to keep out the riff-raff (actually, in an effort to keep unknowing folks from driving up the hill and sweeping observers with their car headlights). Riff-raff or not, I walked around the gate and went up to see what was what. There was plenty of setup space left, but I didn't feel like carrying all my gear up and down the road. Before I left that area, I stopped for a look through a Takahashi 225 mm Schmidt-Cassegrain, a very fine unit indeed, whose optics should make both Celestron and Meade blush.
I went and found my very own parking lot, completely unoccupied and with an excellent view of the sky, so neener, neener, neener to everybody else. I even persuaded a ranger to close off the gate behind me, to keep out the riff-raff. It didn't work, though -- a couple of observing friends came over to see what I was doing. I had the Brandon 98 mm set up and was enjoying a nice view of Mars, at 263x. The central meridian was about 305 degrees, and prominent features included Syrtis Major, Hellas, the north polar cap, and some of the dark markings between Syrtis Major and the cap. The opposition is well past, but the planet will be fun to look at for a bit yet, even with so small an aperture. We also got a nice separation of all four components of nu Scorpii. The brighter pair is supposed to be less than an arc second, and of differing magnitudes, to boot, but I would have called what we were seeing a clean separation. Maybe it has widened since the measurement I used for reference.
I left early, and stopped at my favorite all-night restaurant on the way home. One waitress there knows that I am an amateur astronomer. She asked how come she could still see Comet Hale-Bopp. I was tired -- I told her she could still see it because it was still there. And so was I, but not for long...