I went to "Tranquility Base" in the central coast range. The usual route was closed, so I followed the longer dirt road. I noticed a couple cars heading out as I was heading in. One person drove past around midnight, likely a hunter as his dogs were barking and yelping in the back of the pickup truck -- but otherwise I had the place to myself. Seeing was poor in the beginning of the night but improved. It was dark -- 21.3 by astronomical twighlight, and a peak of 21.55 around 1am -- as I found the next morning driving home, a thick fog covered the Salinas valley.
I brought my NP101 and C8, and it was a rather difficult night. I have trouble balancing that set-up, and if I want to observe an object with the 4-inch, I have to move the NV set-up to the other scope and rebalance. It wastes a lot of time. So in spite of the NP101's optical superiority, I think I need to live with the combo bent refractor. I need to do a close collimation of both objectives in that scope before bringing it out.
I tried for various new objects and observed some galaxies with the C8.
Comet 12/P Pons-Brooks was somewhere below Jupiter, which was setting fast, so I searched for it with the 4-inch but didn't notice it. I used NV 1x and saw what I thought was a hazy area, so I pointed the scope to it and saw a bright coma with a stumpy tail pointed east, which hinted of more flowing beyond the field of view but it was very tenuous.
Next I tried for the Procyon Nebula, but I forgot that it's rather small scale. Using NV at 1x and 3x with Ha, I did notice a very extremely faint, mottled greyscale change primarily to the south/south-east of the main stars of Canis Minor. This turns out to be the outer remnants of the Orion-Eradinus Super Bubble, which is a pretty cool observation by itself, but not what I was going for. I need to try again.
The nearby Seagull Nebula was quite beautiful, and appeared as a bubble with wisps and puffs completing the arcs started by the "wings"
Next I tried some supernova remnants which were the subject of a recent paper. These were so difficult with NV I doubt they are visual objects:
G209.9-8.2, 4-inch and Ha+OIII dual band: Appeared as a very extremely faint eyebrow of nebula to the NE of two "closer" stars. to the south of these stars I saw a long, curved glow, heading south then east, but it quickly petered out when it curved east. I noticed a flow of nebula passing diagonally through the view NE to SW, which seem to be the wider, fainter extensions of the nebula.
G181.3+12.1, 4-inch and Ha+OIII, it is a new supernova remnant. All I saw was a very extremely faint curved north rim, though there seemed a milky haze where the "inside" of the circle the arc, extended, would form. The structure is 9-degrees in diameter and could perhaps be tried with 3x, but very doubtful. I tried to follow the arc around its shape, but quickly lost the rim to the sky background. I did not see G181.1+9.5, which is much smaller and on the inner eastern edge of G181.3+12.1.
Next was a series of galaxies using the C8 with NV, mostly unfiltered. M51 was really spectacular, showing clear spiral structure with three arms, mottling, and a haze around it. I wished to be able to magnify the view more easily (rather than unscrewing the NV). I would have added a Powermate but the extra weight would force me to pause and try to rebalance the scopes. NV certainly showed M51 better than my 20-inch in a dark sky, as I remember it, but the view feels not clean. The cores of the galaxies were much brightened and bloated (as NV tends to do with bright objects). It is like this for most galaxies -- and I miss seeing a "stellar" core which actually looks like a star.
I wasn't taking notes, just cruising around. I moved over to Markarian's Chain and thought to do an experiment. Using NV I was able to very clearly see both NGC 4388 and NGC 4402, two nearly edge-on galaxies which bracket M84 and M86. Switching to glass, I could only see NGC 4388 with some difficulty (brightening averted vision) but I could not see NGC 4402. I was using only a 22mm Nagler, so low magnification, and I might've seen it with higher magnification. But it just points to that NV can show you more galaxies, but perhaps not as aesthetically as one would wish, and certainly not allow easy study of them for lack of image scale.
I will say NV does a very good job with faint edge-on galaxies, making them clearly visible, but again at small image scale. NGC 4517 was very bright, it's bright core off-centered in the mottled long halo. There were others I noticed but didn't make note of.
I spent a fair amount of time on the Gum Nebula, which had risen fairly high. Here is an Aladin Finkbeiner layer representation of what I saw, annotated with the major designations. Also attached is my rough field sketch. The "cometary" nebula is Sh2-311, and it was quite bright. The "SC w/N" or star cluster with nebula, is RCW 19 -- in which I noticed a grouping of brighter stars which seemed like an open cluster, but I don't find a designation for one -- though large and loose NGC 2546 is nearby, and I may have thought they were together. It would be better next time to explore this more closely with the 4- and 8-inch to capture more of the smaller structures.
Toward 1am I repeated my observation of the Spica Nebula, using 1x and 3nm Ha. It's very satisfying to be able to have this "as my own" -- I very much doubt anyone else has seen it.
I need to do a better job planning my sessions, as I didn't remain focused. I wandered around a bit -- Omega Centauri had risen but it was behind a tree -- it was fun to watch stars blink on and off as it moved through the sky. Later, I watched the North America Nebula rise over a rocky ridgeline.
No comments:
Post a Comment