1st time at Dino, very good night.
Equipment: 16" Meade Dob, 35mm Parks, 14mm Meade UW, and Collins I3 light intensifier eyepiece.
(any pictures are not mine, I am just borrowing them for discussion purposes, thanks to those who put them on web.)
Bruce,Rich,others? what was the designation of that big low surface brightness galaxy we looked for near M81? (that we never found)
One of my targets of the evening was NGC 891 in Andromeda. I had seen this a couple weeks ago in Bruce’s 18" scope. It was a scuddy night at Montebello but it looked good. A very low surface brightness edge on spiral "floating" against the background. The I3 eyepiece performs well on edge on spirals so I had put this on my list of next targets, next good evening out. I found it without too much trouble half way between Beta Andromeda and M34. It looked good in my 35mm Parks and I checked it out with my 14mm Meade UW before I blew my darkness adaptation looking thru the I3. It looked good in both, a ghostly UFO like galaxy floating on the starry background, dark lane clearly visible. Looking thru the I3 25mm it was simply one of the best sites I have ever seen thru a telescope. The view thru the 25mm looked just like a small picture of NGC 891. The view was so good, I decided to attach the 15mm eyepiece to the I3. A problem with the higher magnification on the I3 is that it seems to pick up & enhance more of the background heat/light. At Montebello with all the light their this makes for a greener/noisier background. At Dino the problem was much less. The dark transparent night made for less heat/light noise to be picked up by the I3. The 15mm view of NGC891 was also awsome. The UFO didn’t seem to float as in the other views, but there was more detail visible. I will be returning to see NGC 891 again, alot.
This nice picture is very close to how it looked, imagine it in monochrome green... http://www.starlightccd.com/doug/dougastr/images/ngc-891.htm
From reading the I3 documentation, the I3 picks up red light better than blue (almost opposite the human eye) thus when viewing a face on spiral the center will get enhanced while the spiral arms will be reduced, sadly. (center: red, older stars, spiral arms: more blue) Another thing the I3 picks up well is HII regions, thus you’ll get them even if they are in the arms. With an edge on spiral I think you get the best of both worlds. Enough red stars along the entire length to get enhanced, along with the HII regions.
I left the 15mm on the I3 after this. With the dark sky, I was very happy with the reduced noise in the view. In fact, I am thinking that in dark sky situations the I3 might be able to handle barlowing in a more respectable fashion. (just gotta get a good barlow)
Next I decided to try for a more difficult object, I didn’t even know if it would be possible. Last week Ray Gralak posted an image where he had caught the flare up of a Mira type star in the open cluster M46. It turned out there was a whole website of pictures of this star and its surrounding nebulosity. http://www.astronomy.org.il/images/rottenegg.jpg So, using those pictures as a guide, I figured I would try to see the star, which I guess is blowing off pieces of itself to make the "wings" visible in some of the pictures. Even if my hunt was futile, M46 is a pretty neat cluster, with its little foreground(?) planetary in the same view, and the nearby cluster(s) around M47 to distract the bored. It turns out my search was much easier than I expected. Start at NGC 2438, the little planetary in the foreground. Use the "V" shaped group of stars near the planetary to orient yourself, then follow the cross shaped asterism to the target. The length of the cross points right at the "rottenegg". There is another star that the cross points at right next to the rottenegg also, that star was visible in all the pictures, even in some where the rottenegg was very faint, so I knew not to confuse it with my target. My results were curious...
With my regular eyepiece, Meade 14mm ultrawide and my 16" dob I could see most of the guide stars I mentioned. The faintest star in the cross was barely visible, and the star nearby the rottenegg that I mentioned above was also faint. Though both were visible with direct vision. The rottenegg itself was not visible. At this point I didn’t expect much, but when I put the I3 in the result was dramatic. The I3 brightened all the stars, but for some reason it brightened the rottenegg & parent star almost to the point of the nearby star that was visible without the I3!? The Mira star was easily visible along with its small wings of nebulosity. Since the rottenegg showed up so well with the I3 I figured it must have been just on the verge of visibility beforehand. So, I asked Bruce to check if we could see it in his 18", neither of us could see it. We also tried a UHC filter with the 18", and still couldn’t see it.
So, the question I have is, Why did it work so well on this nebula? Is there a way to get the magnitudes of the nebula and surrounding stars, so I could better gage the resulting brightening? Is that Mira star still flaring up?
