> Now everybody go back out and get Fornax.
After sticking my neck out on assorted observational threads on s.a.a. of late, I thought I ought to give at least the local internet amateur astronomy buffs a chance to throw things at me, so on the night of 21-22 October, 1995, I drove to Fremont Peak, expecting the usual fairy ring of telescopes, popping up like mushrooms in the dark of the moon. I was not disappointed. There were probably 50 instruments there, ranging from the occasional itty bitty refractor to the large Dobsons whose mirrors double as coffee-table tops when the moon is full or the weather is rainy.
I took my 10x70 Orion binocular, the model with fully-whizzified optics -- BAK-4 prisms and fully multicoated everything, possibly including the handgrips and manufacturer's label; this same instrument figured prominently in my first successful observation of the Sculptor Dwarf Galaxy. It had been a busy weekend, so I was not able to get down there early. But I did time my arrival to see the constellation of Fornax loom up out of the black pit of the Central Valley -- Fremont Peak indeed has darker sky to the southeast than to the south through southwest.
It was a frustrating night. The thick marine layer of low cloud and fog that can make Fremont Peak a truly dark site had been present earlier, but an increasing land breeze was pushing it offshore, so that the night sky was brightening as time passed, rather than darkening.
Having gone through the usual business of trying to remember just exactly where Fornax was, and armed with a position crude enough to minimize the chances of self-deception based on wishful thinking, I started looking for the Fornax Dwarf Galaxy. Near my rough position I saw two very faint diffuse patches, both at best marginally detectable with averted vision, motion of the field, and so forth. I looked for the Sculptor Dwarf as well -- unfortunately, I had seen it just last month, so knew exactly where to look, so cannot be sure that the unconvincing detection I thought I made was not wishful thinking.
I had brought my Uranometria, and eagerly cracked it open to the page for the Fornax Dwarf. One of my patches lay within the plotted boundary of the galaxy, one was a degree or two northeast. That would be moderately convincing, except with the brightening sky, I could not repeat the observation to my satisfaction. I mentioned to one person what I was trying to do, and remarked that my next goal was reception of etheric vibrations from the ghost of Elvis.
I will try again.
I wandered around looking at and through other equipment. I did not get everybody's name, so will not show favoritism or demonstrate my inept spelling by mentioning those of you whom I do remember. Someone was looking at NGC 246 in a big Dobson; I was prompted to try the 10x70 on it, and sure enough, this large, bright planetary was clearly nonstellar even at a glance. I also looked for and found M76 -- a much tougher object. I have seen it with a 7x50, but on a better night than that one.
Several of us spent a while looking at M42/M43 through a 155mm Astrophysics refractor; I foolishly did not write down the magnification, but I think I remember that a 16mm eyepiece was in use, which would have made it about 87x. I think the consensus was that the heart of M42, near the Trapezium, showed clearly greenish, whereas portions (but not all) of the rest of the nebulosity showed color that appeared to be different than the part by the Trapezium, but not all of us agreed that that color was reddish (I thought it was). The differently-colored portions included most of M43, and the brightest portions of the nebulosity adjacent to the dark "wings" of the nebula, that run vaguely east and west between M42 and M43; the colored portions were immediately adjacent to the wings and on the side toward M42. This stuff could in principle have been attributable to contrast effects, though it is suggestive that not all the non-green stuff was red, and that the color we saw was where red shows up in photographs. Of course, we all had seen plenty of those photographs. We had a long philosophical discussion about the perversity and probability of contrast effects making you think you see color where color actually is present and would vertainly be visible in a larger instrument.
We looked for the Horsehead Nebula in several instruments. In a 17-inch Dobson at 77x, with a Lumicon UHC filter, IC434 (the background nebula) and B33 (the Horsehead) were well seen; I could hold the Horsehead with direct vision. Without the filter, there was no trace of either. We tried the 155mm Astrophysics refractor with both 44x and 54x, with both a Lumicon H-beta filter and a Lumicon UHC filter. We tried each filter on each eyepiece. The best that some of us could do was suspect B33 at 44x with the UHC filter, though IC434 seemed visible with all four combinations. It was interesting that the UHC filter was doing a better job than the H-beta.
These observations led to an interesting discussion. I have seen the Horsehead in a 6-inch with no filters at 36x on a much darker night; I could even hold it with direct vision. The night of 21-22 October was certainly not so dark, but these filters surely reduced the background glow to as dark as that in any unfiltered observation made this side of low Earth orbit, presumably without diminishing the light from IC434 by any significant amount. Why, then, could we not see the Horsehead in the Astrophysics refractor with filters? One guess had to do with dark adaptation. The brighter sky and occasional lights of camping stuff may have deprived us of that last bit of adaptation that may have been necessary to make a difference. One of us had a hood handy, but we were by then too lazy to dig it out and try it. (I didn't do the pull-up-the-jacket trick becaue I was cold, and wanted my jacket for warmth.)