Report from Sonoita Hills Observatory

by Mike J. Shade


After a wait of almost a year, the 22-inch telescope has been installed in Sonoita Hills Observatory (SHO). I'll start by saying that this telescope is huge, nicknamed the monster for good reason! In brief, it is a 22" f/5 Newtonian on a German Equatorial Mount (GEM). The mount has 6.1" steel shafts and the main bearings are surplus (never used) bearings for the props of a B29 bomber! The weight of this thing is some 2000# or so. The mirror is a Pegasus mirror and based on what has been seen so far, it is a good one-estimated final optical quality is something on the order of 1/8 to 1/10 wave. The nose piece rotates and unlike my NGT-18, does not radically change collimation as it is rotated. It rotates on a large circular flat bearing. The 18 inch Byers RA gear is accurate, Byers says it is a two arc second gear! The telescope pier is filled with some 200# of sand and bolted to a 36" diameter 6 foot deep concrete filled and reinforced sonotube. This is of course isolated from the observatory floor. The observatory is a 16X16 foot roll off roof type, with eight foot high walls. Inside are two computers-a laptop for running the positioning software (Mel Bartel's system) and a desktop for running astro-software and the CCD camera.

The instrument is not finished-the DEC motor and tangent arm needs to be done, as do the slewing motors and electronic clutches. there are a few more things to do, but nothing major. We did have one problem on assembly-balance! The OTA was bottom heavy so we had to move the OTA up 12 inches, which of course moved the eyepiece up the same amount. We are going to try and get that foot back since this thing sticks waaaaaaay out of the observatory and it is a big ladder!

Furthermore, this is not a "fast" telescope-I pick objects in the same area of the sky and work a small area. Imagine swinging a VW around-this thing takes time to move, position the ladder, go up the ladder, and so on. My NGT-18 took me up one step on the ladder, this one takes me up 6 or more feet! While it is smooth, it is ponderous to move.

After the initial shock wore off (this is a big telescope, it's mine, AND IT'S IN MY BUILDING!!!!!), I have actually used it visually and kept notes.

This morning (I got up at 3 or so), I started with NGC (N) 6210 a planetary which I saw as small, circular, and quite turquoise-it was slightly darker in the center (22mm Panoptic, 121X or so). N 6765, another planetary was more oblong in shape, with even surface brightness, and slightly tapered in the middle at 121X. The pair of galaxies N6703 and N 6702 were interesting because of the contrast-N 6702 was softer looking while 6703 seemed sharper defined. The planetary nebula PK64+15.1 was triangular, even surface brightness-it looked more like a galaxy than a nebula.

Tonight, I pushed this thing to the limit. I warmed up on N 2903 and with a 12mm Nagler (231X) it was elongated with two prominent star clouds and numerous dark tapering dust lanes. N 2911, 2919, and 2914 were interesting and there was a "texture" to 2911 at 231X. In the are was U5093 and CGCG63-12 at magnitude 15.42. Also noticed was 82W49, at magnitude 16.39. This last one was dim. going deeper, I turned to IC 552 at magnitude 14.4-easy enough. CGCG63-42 at magnitude 15.28 was tougher. Getting brave, I looked for and believe I saw PGC27698 at a magnitude of 17.3 (this was not much of anything, let me tell you...). All of these were at 231X or so. Tired from this adventure into the world of dim and bizarre, I turned to more interesting objects. N 3024 showed evidence of dust lanes at 231X. N 3628 showed its dust lane easily enough, but brighter portions were noticed in the central portion of the galaxy. M65 showed a very faint spiral pattern while M66 showed two faint dust lanes on the E side of the galaxy, with a third suspected. The "hook" seen in photographs going off to the south was detected but was exceedingly faint. N 4565 was well...BIG at 231X! Dust lane had several notches and such in it. More than filled the field of view at 231X. Finally, I ended my romping into galaxy land with N 4725 which was big, bright with a prominent central bar with extensions. The extensions reminded me of umbrellas covering the central bar.

This looks like it will be a good instrument and after I get the rest of it done, should do well with a CCD camera or regular film camera. I can't wait.