Posts Made By: Kim Colter

I rolled out at 2 AM and headed for the 40 inch f5 Dob. Clear sky clock was showing blue for transparency and seeing. It was a splendid night but about 19 degrees and still. It wasn't long until I had the hair dryer running to get frost off the secondary. I started by failing to see the central jet in M87 for about the 12th time. I went to the Coma cluster of galaxies and saw 40 to 45 tiny galaxies in one 31 Nagler field--"lumpy sky" as they say. I swung over to M51. It was a stunning view with a 13 Nagler. I intended to put the 16 Nag in that was in one pocket of the Feathered Friends parka but inadvertently slipped the 9 Nagler in instead. The field of view would no longer contain all the spiral structure and the dust lane in the bridge was clearly visible with direct vision. I also looked at the Hercules galaxy cluster. The Coma cluster is more impressive, I think. After some more galaxy cruising astronomical twilight was beginning. I was using the hair dryer more and more and as it began to get light noted frost on the shroud, my coat, my hat--hence the Coleridge line, "the ice, the ice, was all around." That view of M51 was worth the hassle with the frost.

As astronomical twilight was beginning yesterday morning I stumbled across Campbell's Hydrogen Star in Cygnus on the chart in Keppler and Sanner's, "Night Sky Observer's Guide" and tried to find it. I was using the 20 inch Starmaster. I did not locate it. Fatigue and the onset of twilight may have been a factor in my failure to locate it. A cursory search on the web indicates that this object may be enhanced by the use of an H-beta filter. I am interested in observations made by others of this object. Did you find an H-beta filter useful? How subtle is this object? Thanks for the help.

Anyone have any data or speculation about what creates the propellor asterism in M13? Is it an illusion that arises in our central image processing centers in geniculate ganglion or occipital cortex, or is it in fact something about the nebula? Could it be created by dust, differing densities of stars in parts of the cluster, or what?

I thought I posted this thread in the deep sky forum and found out to my chagrin that I posted it in "After Dark." I am interested in the opinion of the deep sky observers and neuro-ophthalmologists out there about the source of the "propellor" that can be seen in M13. The sole response I got in the After Dark forum felt it was artefact, not something really present in the globular cluster. I can accept that, but wonder why we see it in M13 and not in other large bright globs, and why we all see it in the same place within the glob (do we all see it? do we all see it in the same place?) I suppose it can be said there are numerous non astronomic examples of "tricks" that can be played on our visual systems by putting dots of ink on paper in a certain way that has us all seeing the same "apparition." Is there something about M13 that is unique and causes us to see the propellor? The responder in the After Dark forum felt that the propellor went away in very large apertures. I see it better in my 20 inch and 40 inch than I do in smaller scopes. Thanks

Al and David Nagler were at TSP and demonstrated the soon to be released Dioptrix attachment that corrects for astigmatism. I was thrilled by the improvement it made in my view at the eyepiece. One needs to know the number of diopters of "cylinder" in the prescription for the eye you observe with. The attachment fits the TeleVue eyepieces that produce large exit pupils. Interestingly, I could notice a subtle improvement in my vision even with eyepieces that produced a 2mm exit pupil. I did not have the opportunity to try the Dioptrix attachment out under clear skies, it was demonstrated at the vendor building using an eye chart. I think that the more astigmatism one has the more one will appreciate this accessory. It will be extremely useful for observers with astigmatism when they use the 31 and 26 Naglers, for instance.

We don't often report naked eye and binocular deep sky observations here. The highlight of a cloudy week at TSP for me occurred in the three hours before dawn at the end of the star party when I used Nikon 20X120 binoculars and my naked eyes on the Milky Way from below Sagittarius to Casseopia. The star clouds in the Milky Way reminded me of what one sees in long exposure wide field film astrophotography. Globular clusters were bright with the largest ones (M22) on the verge of showing resolution of individual stars. The entire veil nebula was visible in one field of view without filters. M27 and M17 were lovely. My friend, Bob Kirschenmann, pointed out that with fully dark adapted eyes one could see faint shadows from the starlight. All in all a wonderful end to a cloudy week.

My friend, Bob Kirschenmann, had the prototype for the Starmaster V11 at TSP. While the number of cloudy nights at TSP was a disappointment, the V11 was not. The images through this scope were astonishingly good. Jupiter was seen incredibly well through this scope. My only comparisons were to two adjacent 20 inch Dobs with Zambuto mirrors. The size of the air cells in the atmosphere must have been such that the 11 inch had the best view of Jupiter. The double double through the V11 was perfect, a view befitting a Zeiss refractor.
Thought I was posting this in the Starmaster forum but it ended up in "After Dark."

Reading comments in another forum I realize that if we don't have some posts, we may lose the forum. So, the last two nights I have had some nice views of Jupiter in the Zeiss 150/2250. I think the best focal length eyepiece for the conditions I have had is an AP 12mm Superplanetary, 16mm Zeiss ortho very nice as well, 10mm Zeiss ortho a bit much for the seeing. This objective has some obvious false color that is most noticeable on bright stars but is something I can look past for the most part.

Last night discovered a major mouse infestation in my roll off roof observatory. The little buggers ate holes in the fabric covers at both ends of my 12.5 inch finder scope and built a nest in the tube. Looks like they rubbed their little mouse noses on the mirror while looking at themselves. I brought the finder back to do a thorough cleaning. I need to decrease the population considerably. With the roll off roof it isn't easy to make the building tight enough that they can't get in. Anyone else dealt with this issue? Thanks

When I had the chance to use the new Dioptrix attachment in the building at the expo at TSP I was wildly enthusiastic about it. The cloudy weather did not afford the chance to use it at night at TSP. I just received my Dioptrix and have tried it on my 31 Nagler. I am using the Dioptrix with the same level of correction as my glasses prescription has. My results under the night sky are less pleasing than my results looking at an eye chart through a telescope during the daytime. I suspect that the difference has to do with my pupil size being different in the two circumstances. I rather suspect that I have more astigmatism when my pupil is dilated to 6 to 7 mm at night than I do during the day when my pupil is dilated to 3 mm.
It would be lovely if there were a way to try the various diopter levels of correction on one's eyepiece at night in order to pick the one that affords the best correction. I would be interested in hearing whether other people with significant astigmatism have had similar experiences with the Dioptrix.
On a parallel track, I have found that some people who have had corneal refractive surgery and are delighted with the results during the day are disappointed with what they see and don't see at night. I think most of the corneal refractive surgery done corrects the central 3mm of the optical axis but does not correct the outer "ring" of a fully dilated pupil. "Turned down edge" on one's own cornea messes up an image even more than TDE on a mirror or refractor objective, it would seem.