OBSERVING NOTES – 82” @ McDonald Observatory, Nov 17/18, 2006

82”, F13.7 Cassegrain, 812X using 35mm Televue Panoptic, yielding a 5 arc-minute FOV


I had the opportunity the new-moon weekend of Nov 17/18, 2006 to spend 2 nights at the eyepiece of the 82" telescope at the McDonald Observatory near Fort Davis, Texas. There were 16 observers altogether. We were able to stay on-site at the Astronomer's Lodge, which includes both room and board, with snacks available 24 hours a day, and were only a 2-minute walk from the dome.


This telescope was completed in 1939, is 27 feet long and weighs 45 tons. With the eyepiece at the Cassegrain focus it configures to F/13.7, and a 35mm Televue Panoptic yields a 5 arc-minute FOV and 812X. Other eyepieces were available, but seldom used.


As you might imagine, when slewing from one object to another, the height of the eyepiece above the floor can vary quite a bit, and that problem is solved by having the hydraulically-operated floor move up or down to provide a comfortable viewing height. The difference between short and tall people is easily solved with a short but sturdy stepladder. The dome has a catwalk around the outside, accessible from the observing floor, so it is easy and convenient to step outside and view the night sky at any time. Adjacent to the observing floor is the control room, where you can power up your laptop and plug into the internet, get hot coffee and snacks, or simply sit in a comfortable chair while waiting for your next turn at the eyepiece.


A telescope operator was supplied as part of the package, and he would advise us as to the suitability of whatever object we selected to view. Because this instrument is getting a little cranky in its old age, we were advised that our declination limit was -25 degrees, and knowing that in advance allowed me to prepare an appropriate list of objects. I used SkyTools to generate a list, and I then spent several nights eliminating objects that were either too big or too boring. I ended up with almost 200 items, with notes, and shared this list with the rest of the group, asking for both positive and negative feedback. Receiving none, I printed the list, figuring we would pick-and-choose as we went along.


I ended up taking notes on 49 items, as follows;


NGC 6826, Blinking Planetary, Cygnus

Large blue-green, 2-stage oval, slightly elongated E-W. The central portion has slight ansae at the ends of the long axis and has stronger color. The fainter outer ring has a sharp outer edge.


NGC 7026, Cheeseburger Nebula, Cygnus

Rectangular shape with dust lane dividing it into 2 almost equal segments. Central star not noticed. This was none of the first objects viewed and I was too awed to look for much in the way of details.


M-15, Pegasus

We could only see the central 5 arc-minutes of this 18'-wide globular, and it looked just like it does in my 25" when I'm looking at the whole thing! Pease 1 was the secondary target here, but no one had a definitive map of its location; several people felt they saw a pinkish dot in there somewhere, but I did not. Spectacular just the same.


Neptune, Capricorn

Big and blue, but the seeing was poor and the image was not steady. Well, poor if you consider 1-second seeing to be poor... seeing improved later in the evening but Neptune was gone by then.


NGC 7008, Cygnus

Sometimes called the Fetus Nebula - spectacular in this telescope. Technically a disk, but there are so many internal bright clumps that your first impression is one of a very complex, non-round object. There are several stars superimposed on this PNe, including the easy CS, and a bright double off the north edge completes the superb picture.


NGC 7009, Saturn Nebula, Aquarius

After previewing photos of this guy, I expected to see lots of intricate detail, but it was not to be. It was, however, a wonderful and unique object. The elongated central portion looked just like a rugby football, with a baseball attached to each end, the whole thing being very bright. I didn't notice a central star, but this object was observed early in the evening, before the seeing settled down, and it was hard to remember details because I kept tripping over my jaw, which was still near the floor. It took a while to get it under control... ;-)


Saturn, Leo

Well, words are simply not enough to describe the view of Saturn. Just find a Hubble picture and you will get a good idea of how it looked. I was surprised that while there were several colored bands of clouds visible, the colors were very subtle; a wide pale purple-pink band in the southern hemisphere was the most prominent. Nothing resembling a storm was seen. The usual ring divisions were quite evident, and the Crepe ring was riveting, I couldn't keep my eyes off it. I looked for but could not see any sign of spokes. I suspect that the low angle of the rings right now made this a lot harder than it might otherwise be. Titan was clearly a disk; I should have expected it to be so, but it came as quite a pleasant surprise. 7 satellites were seen, including (from nearest to farthest from the planet) Enceladus, Tethys, Mimas, Dione, Rhea, Titan, and Hyperion. Iapetus was at about 360 arc-seconds away and well out of the 5 arc-minute FOV, but I didn't slew over to it because there was quite a line behind me...


NGC 7331, Pegasus

Although this galaxy is over twice as big as the telescope's FOV, it was still a show-stopper in the 82". Using the slew buttons it was like flying over the thing.  Several HII areas were suspected in the outer fringes, and several companion galaxies were evident, most notably NGC 7335/37.


NGC 7320, Stephan’s Quintet, Pegasus

This group was on everyone's object list, and rightly so. Spiral structure was noted in NGC 7320, and maybe in NGC 7318 (sometimes referred to as NGC 7318B). I had to scroll over a bit to pick up NGC 7320C (not one of the Quintet) because it would not fit into the 5 arc-minute FOV with the rest of the group. Quite a sight.


Uranus, Aquarius

Big and blue-green, the seeing had not yet settled, but Ariel and Titania were seen on one side of the planet and Umbriel and Oberon were on the other side, more-or-less in a line; all are in the 14th - 15th mag range.


NGC 68, Andromeda

A large group of small galaxies, maybe 10 or 11 seen in the eyepiece at the same time. Cool


NGC 145, ARP 19, Cetus

"Small face-on spiral galaxy with highly distorted arms and a big lump on one side of the core... very nice.


NGC 210, Cetus

Large spiral, faint outer arms, distinctive elongated core, overall mottled appearance, several HII areas suspected, smooth outer edge.


NGC 246, Cetus

Completely fills the field of view at 812X, large ring around the outside with a fairly ragged edge. Double star in the center, I suppose one of them is the CS.


NGC 281, Cassiopeia

Although this bright nebula itself is way too big for the 5 arc-minute FOV, the targets here were really the Bok globule near the middle and the nearby HD 5005 trapezium-like multiple star. The Bok globule was clearly visible, but not nearly as contrasty as I thought it would be. The multiple star was obvious, and made for a very pretty picture. At 812X the 1.6" AB pair was easily split. Of course, there was a lot of nebulosity coursing through the whole area.


NGC 604, Triangulum

Residing in M-33, this is one of the largest H-II areas known; being 1500 LY's across, it would fit between us and M 42, itself 1500 LY's distant. In the 82" it was as though you were there, flying high above this nebula, which had some structure, but not too much.


NGC 650, Little Dumbbell, Perseus

M-76, with 2 NGC designations, NGC 650/51, this looks like a collision of gas clouds, a bright bar with lesser nebulosity on each side. Very nice.


NGC 908, Cetus

A large starburst spiral that completely fills the 5 arc-minute field of view. One of the prominent arms splits near its end into 2 very distinct, ropey tails. H-II area abound throughout the galaxy. Quite a nice surprise, one of the highlights of the night.


NGC 945/948, Cetus

A galaxy pair, both face-on spirals, and both in the same 5 arc-minute field of view. The DSS picture was very promising, but in actuality the sprial structure of each galaxy was very weak, although clearly present. If this had been the only object viewed I would have been absolutely thrilled with the view, but in comparison to other objects on the list it was a little ho-hum and we moved on to bigger and better things with little comment.


M-77, Cetus

This Seyfert galaxy has a very chaotic nucleus, very interesting in the 82". It was a bit bigger than the 5 arc-minute FOV so you had to look all over the place to see the broad arms that showed clearly in the eyepiece. High on the list of favorites.


NGC 1073, Cetus

Classic barred spiral, like a dimmer NGC 1365; strong bar, weaker arms that completely encircle the nucleus. In this outer circle there are several H-II knots visible.


NGC 1232, Arp 41, Eridanus

Textbook face-on spiral, this is the object that graces the cover of Skiff & Lugenbuhl's Observing Handbook. It has a large arm that sticks out like a cowlick and wraps around to the north, and opposite this is NGC 1232A, a companion galaxy that looks, in real time, like it might be an H-II knot.


IC 298, Arp 147, Cassiopeia

I wanted very much to look at these guys because the DSS shows them to look like the letters "I" and "C", and by golly, they do! Very cool.


NGC 1300, Eridanus

NGC 1365 was too low for this telescope, so NGC 1300 was chosen as being the best substitute, and it filled that bill admirably. Having the classic barred-spiral shape, with a long bar and 2 prominent arms emanating from that bar at 90-degree angles, then wrapping completely around the core, this object was simply mesmerizing.


NGC 1501, Camelopardalis

A small but bright PNe with a bright CS. Not much variability in the crisp-edged disc but it does have an overall mottled appearance.


NGC 1569, Camelopardalis

A dwarf irregular galaxy that may belong to the local group. This galaxy is home to several SSC’s, Super Star Clusters, that are very apparent in this telescope. The galaxy itself is a bright slash that fills most of the 5 arc-minute FOV, and the SSC’s show as 2 non-stellar bright regions aligned along the long axis of the galaxy. The literature suggests that these SSC’s have an absolute magnitude 3 mags brighter than Omega Centauri does.


NGC 1514, Crystal Ball Nebula, Taurus

This PNe had a very large halo, not perfectly round and with a lumpy-bumpy outer edge. The interior of the disk is almost completely filled with a 4-lobed shamrock-shaped dark area. The central star was obvious. Curiously, this was the only PNe of the weekend that responded to the OIII filter, all the others simply looked about the same. Very unique.


NGC 1535, Cleopatra’s Eye,  Eridanus

Bright dual-shelled PNe, both shells aqua in color. The bright inner shell has a ropey, intricate outer edge, while the dimmer outer shell is featureless and has a nice sharp outer edge. Bright central star. Very dramatic at this aperture.


NGC 1555, Hind’s variable Nebula, Taurus

Unusual shape, but easily seen, it looked like 2 intersecting slashes of nebulosity. Not a barn-burner, but nice nonetheless.


NGC 1888, Arp 123, Lepus

Interacting galaxies, the larger edge-on galaxy has the smaller round galaxy sitting right on its central bulge. Not much other detail, but a very nicely framed pair.


IC 418, Lepus

This smallish PNe is said to have a red rim. When I first put eye to eyepiece this red rim was obvious, but after just a few seconds the red almost completely disappeared! If I closed my eye for several seconds, it came back for a moment or 2. Anyone have an explanation? Otherwise, this is a bright planetary with a bright CS. The interior was not exactly smooth, but not exactly detailed, either, very hard to describe. I guess that the word "mottled" works here. It seemed to me to have an overall color, but it was difficult to tell exactly what that color was... hmmm... a very curious object.


NGC 1952, Crab Nebula, Taurus

The Crab Nebula was both spectacular and a little disappointing at the same time. It was a little bigger than the 5 arc-minute FOV and very bright, but I didn't see any of the detail that shows up in photos, there was none of the spider web detail that I expected to see. The central pair of stars were quite obvious, one of which is the pulsar, but I don't know which was which. It really was a nice object, spider web or not.


Trapezium, M-42, Orion

The trapezium is one of the few objects to be viewed both nights. The first night the seeing was just not good enough to see any Trapezium stars other than A-F, but the second night the seeing was nearly perfect, maybe 1/3 arc-second, and then I could easily see G and I within the trapezium and H (but not H') just outside. I had printed a terrific finder chart and photo of the area and could see just about every star in the field. I looked for the proplyd "tails" on the G, H and I stars, but they were just not there, nor was the shock excited [O III] arc near G visible (well, I can dream, can't I?) Almost as an afterthought, after looking only for the difficult objects in the field, I finally noticed the nebulosity! It was exactly like looking down on the clouds from above while in an airplane, puffy clouds as far as the eye can see. What a sight!


NGC 1999, with Herbig Haro 1 & 2 nearby, Orion

NGC 1999 is a bright diffuse nebula with a distinct triangular dark spot near its center. Many observers said it looked like Africa. It is a terrific object in my 25" and was spectacular in the 82", and exceeded my expectations. However, one of most exciting areas of the weekend was just south of 1999. Armed with a good photo and being able to identify the field with full confidence, HH 1 & 2 were spotted with direct vision. Oh, they were faint, but they were there. Whoa thunk. What a treat!


Beta Mon

Triple star. The goal here was not to split this not-so-difficult triple, which was very easy, but to see the nebulosity in the area. The nebulosity was there, but it only made all the stars in the field look "wet", there was no detail at all. The triple was very pretty nonetheless.


PGC 17744, Lepus (05 45 47.8  -25 66 30)

A group of perhaps 12 galaxies within the 5 arc-minute FOV, the brightest only mag 14.5 and easily viewed with direct vision. Averted vision showed the entire field to be littered with galaxies. An impressive array.


M-78, Orion

M 78 was nice and bright, but was deemed to be a disappointment because that was all there was, nebulosity, there were no details at all to be seen.


NGC 2207, Canis Major

NGC 2207 and IC 2163 are 2 interacting spiral galaxies that are framed perfectly by the 5 arc minute FOV, and they were one of most pleasant surprises of the entire weekend. 2207 is fully face-on and has a classical shape, the arms are broad and distinct and easy to see at this aperture, and the spiral structure seems to go all the way into the center. 2163, on the other hand, is kind of "eye" shaped and has a showy tidal tail trailing outwards from the pair, but does not reveal much spiral structure in the eyepiece. Perhaps the best pair of the weekend.


NGC 2261, Hubble’s Variable Nebula, Monoceros

NGC 2261 was another winner, a distinctly fan-shaped nebula radiating away from R Mon. The edges of the fan were sharp but the edge farthest from R Mon just sort of dissolved to nothingness. Immediately north of R Mon there is a finger-like dark nebula that seems to wrap around the star, partially detaching it from the nebula, and making the pointy end of the nebula fairly hook-shaped. A recent Amastro post by Tom Polakis indicates that this dark finger of dust might be a new "variable"...


NGC 2346, Hourglass Nebula, Monoceros

Not much of an Hourglass shape at this aperture, although there was a V-shaped dent on one side. The main portion of this nebula was nearly circular and amorphous to my old eyes. Maybe the telescope was slightly off-center and I just missed the shape. It was late the second night and I was getting tired.


NGC 7479, Pegasus,

This barred spiral has 2 major arms, and completely fills the 5 arc-minute FOV. One of the arms is very subtle and wraps back on itself near the bar, while the other arm ventures far from the nucleus and  forms a huge loop. A very unique object in this telescope, and a wonderful surprise, I didn’t expect it to look this good.


SRWW-1, Monoceros (07 16 3.8  -01 53 31)

This possible protoplanetary nebula was brought to my attention via an E-groups post by Kent Wallace some time ago; I filed it away for just this occasion. After the telescope was slewed to the coordinates, I took a quick peek but saw nothing. I had prepared a detailed finder chart and DSS photo but I could not identify the field. 2 other observers had a try, and wouldn't you know it, they did ID the field and each states that he saw something at the exact location of SRWW-1. Nothing definitive, but something. I tried again, but still couldn't get the field, and finally gave up, disappointed. :-(


NGC 2371, Gemini/Peanut Nebula, Gemini

At this aperture this is a large, bright object, bipolar, somewhat elongated, with an obvious central star. The dark lane I see in smaller telescopes is not particularly dark at all in the 82", there is some nebulosity there. I forgot to look for the "polar caps" that show in deep photos about 1 diameter off the ends of the axis of the dark lane, I'll bet they were there... :-(


NGC 2392, Eskimo Nebula, Gemini

The Eskimo was bright, a little elongated, and was another disk-within-a-disk object. The outside of the inner disk was oval with one end flattened and was distinctly ropey, showing lots of fine detail. The outer shell was much more amorphous and showed very little detail. Both shells were aqua in color, with the inner shell having a stronger hue. In retrospect this object looked a lot like NGC 1535, only larger. If it weren't for the long line of observers behind me I could have looked a this guy for a long time.


NGC 2366, Camelopardalis

OK, this is a fabulous object with an identity crisis. Many sources tell us that NGC 2366 is a dim galaxy with a "hot spot" labeled as NGC 2363, which turns out to be a Super Star Cluster and one of the largest HII areas known, on a par w/ NGC 604 & the Tarantula Nebula, but the NGC/IC project puts all of this in doubt, and I leave it to you to go sort out these details on your own. Whatever the labels may be, this is a wonderful object at this aperture. Not many of the observers on this night had ever heard of this pair, but all were suitably impressed with the view. The galaxy completely filled the 5 arc-minute FOV and the SSC's dominated the view. It appeared to have several nuclei and presented a lumpy appearance. A very nice object within this dwarf galaxy which is part of the M 81 group.


NGC 2419, Lynx

The Intergalactic Wanderer is among the 4 or 5 farthest globular clusters in our galaxy, and when viewed with most amateur telescopes no individual stars can be seen. Using 82" of glass I counted 8 or 9 stars in one quadrant, so maybe 3 dozen stars were seen overall. Other than that, just another pretty globular, very uniform in appearance...


NGC 2438 in M-46, Puppis

This planetary nebula in M-46 presented as a perfectly smooth and uniform ring with no discernable color to me. There were several stars involved in the nebulosity but none seemed to be in the exact center. The real target in this area, for me, was the Calabash Nebula, (OH231.8+4.2) 6.5 arc-minutes east and a little north (PA 79) of NGC 2438. Unfortunately, I left my detailed finder chart back in my room that first night, and the second night there were just too many objects left on the "must see" list to get back to this guy. Maybe next time... :-(


M-87, Virgo

M-87 is just another giant elliptical galaxy, and they all look pretty much the same, no matter what size telescope you use, right? Well, probably true, unless there is a relativistic jet involved. At 812X the jet was very obvious. I didn't know what to expect, but the jet was a razor-thin streak that went from nearly the galaxy's center straight as an arrow out of the galaxy and a little beyond. I was so entranced by the view that I completely forgot to look for the many globular clusters in this galaxy. Bummer. That's another reason to return to this telescope in the future.


NGC 3242, Ghost of Jupiter, Hydra

Well, this might have been the best object of the weekend, Saturn notwithstanding. It was just as I remembered it to be when I viewed it through this same telescope in 2000, during the TSP. This PNe has a large slightly oval shape and shows multiple shells, with a bright central star, several other observers used the word "bagel". The innermost ring is small and dark, and had a purple-tinged outer edge. The next shell outwards is a bright crepe-like ring, shocking aqua in color. This is followed by a broader ring that is distinctly salmon or pink in color, my notes call it a "filling", and virtually everyone saw it this way. Lastly was another aqua ring, thinner than the pink ring, and not quite as vibrant in hue as the other aqua ring; it is almost perfectly uniform in width and looked like a racetrack. Curiously, the real-time view in this telescope looks nothing like any picture of this object that I have seen, and I've searched extensively to find a picture that even slightly resembles what I saw. None at all. To see this, I guess you need to book a night on the 82"...


There were many objects on the list that went unobserved, but 2 nights was simply not enough time. I wanted to view several more “off the beaten path” objects, or objects that may never have been visually observed before, but with 16 observers, all waiting patiently for their next peek, anything that wasn’t easy to find and showy in the eyepiece wasn’t exactly top priority, which is perfectly understandable.