We had some rain the end of last week, and once that air mass moved out we had some rare clear weather yesterday and last night. There was still some high water vapor, and seeing wasn't perfect, but good all the same. I drove down to Pinnacles where six others had gathered for a night of viewing. Since it's dark early, I arrived at 5:30pm and started observing around 6:30pm. SQML did not get above 21.00; I suppose too much moisture in the air. Fortunately the ground level stayed dry, and it did not dew as I feared it might. I didn't note when I stopped, but it was about an hour after the others left, so sometime around 1:30 or 2:00am. I slept a bit in my car and left around 6am.
I had my 10-inch Springsonian. Instead of the Pocket Sky Atlas, this time I brought my Interstellarum atlas to try some challenge objects, mostly planetary nebula in Cassiopeia. I had a number of dubious and marginal observations, and I realize if my interest is with these obscure objects, I really need to have a large aperture scope. The 10-inch is nice for wide field and I do try to fulfill that purpose, but it's really a bit limited.
First up was Comet 88P/Howell, which was an easy find below Jupiter -- just beyond the field of view in the scope. It was a small, very weak round glow, with diffuse edges and a faint pseudo-nucleus. It was a little enhanced with the comet filter. In a very rich field. The comet was actually better seen in my 8x50mm finder as a small white patch, well offset from the surrounding sky. I did not come back to it as it set a short time after.
Next was the area around Beta Cassiopeia, the starting point for my nebula searches. Open cluster AI 20 was an unimpressive group of similar magnitude stars in a wedge shape. Between it and Beta Cas was a rather broad patch of nebulosity, a darker sky background between them. Reflection nebula vdB1 bordered AI 20 and was a brighter cloud with some stars intermingled with it with some mottling or knots in the nebula. vdB1 is 1600 light years away and five light years across. There are two Herbig-Haro objects [which are emission nebula from mass ejected for newly formed stars], HH 162 & HH 164, plotted in this area, but I did not notice them (I was using only 35x).
CTB 1 = Abell 85: This is an ancient supernova remnant, which in astrophotos appears large, about the size of the full moon, and a completed circle. Abell first thought it was a planetary nebula but it was confirmed to be a supernova remnant in 1971. What I saw is the brightest arc along the southern edge of the SNR, near the pointed triangle of stars, which appeared as an extremely faint wisp with ragged ends. I could see it with both OIII and NBP filters, but the unfiltered view was best. Astrophotos show a shell rupture on the opposite [NE] side from this arc. The SNR is about 9700 light years away, 98 light years in diameter, and is thought to be 10,000 years old.
Sh 2-176: I had a very tenuous / doubtful observation of this planetary nebula. Using a printed chart I found the right area of stars and at 50x with an OIII, I had an impression of a thin arcing glow running through one of a close pair of stars. It was exceedingly faint; the surrounding sky was just a bit darker. With more time observing the area to the north of the arc seemed to fill with a light milky haze to appear more round. It may be from bias from looking at the printed finder which included a photo...
NGC 281 = Pacman Nebula. On to some brighter fare. I had not seen this object before, and it was a treat. At 35x I could see the nebula around the brighter stars of the small open cluster IC 1590. The nebula expanded into it's distinctive fat kidney bean shape with OIII, with unevenly crimped outer curve and a branching tree like dark nebula cutting one third of the nebula from the inner curve N-S, forming two lobes, one of which is brighter. I noticed two patches of nebulosity around the two brighter stars "behind" the Pacman (to the SE of the outside curve about half a degree away).
WeSb 1: Weinberger-Sabaddin 1. Attempted this one with 35x & 50x & OIII, and wrote "Extremely weak small round glow and blinking central star...poor line of six brighter stars with a few more above and below [outside the open cluster AI-Teu 1 approximately where the PNe should be], with faint sense of glow on one side of the string." However reading the discovery paper, I find only a 15" half round glow was detected, and my observation is very doubtful since what I saw would seem to be too large, and I doubt prior observers would overlook a blinking star. Uwe Glahn has a negative observation with a 16-inch in excellent conditions. Interestingly, however, the PNe does appear to be on one side of a string of stars... AI-Teu 1 is a rather large cluster, loosely formed of moderately bright and faint stars, probably around fifty in all, nicely detached from the surrounding field.
To the north of Gamma Cas are two reflection nebulae, IC 59 & IC 63, which appeared as a haziness like a fog on the eyepiece. It was best to keep Gamma out of the field. IC 59 was smaller and lay between two bright stars to the north; IC 63 was to the east and was larger and more diffuse, mottled, with ill defined edges.
NGC 225 is a fun little open cluster that looks just like a sailboat: A string of five stars topped by a triangle shaped asterism of medium and fainter stars.
Semeis 22: At 35x with OIII, this appeared as a faint but plain crescent, a bit less than half a circle, with some very subtle mottling and a bit brighter to the north. The outer edge was more defined than the inner. It has lost its full round shape with interaction with the interstellar medium, so it is considered to be an old PNe.
Next I had a look at the "Heart and Soul" nebulae, from NGC 896, IC 1805, and IC 1848, along with numerus involved open clusters Teu 55, Mel 15, NGC 1027, Cr 32, 33, 34. It's a bit much to describe, other than the extensive nebulosity running between and among star clusters, covering several field diameters. I used the NBP filter.
I then had a look at two more emission nebulae,
vdB14 & 15. vdB15 surrounded bright star C Cam and made it have a bright hazy blue halo; vdB14 was an almost degree long elongation to the east of a double-double star, STF 385 & STF 384. STF 389 was in the field, as was STF 396 on one end and STF 400 on the other. Webb 2 was just beyond the field, it has a red primary. There was an arc of ten brighter stars in the scene to help orientate me.
Kemble's Cascade was next, and the whole string including open cluster NGC 1502, with the bright pair in the middle, fit the field. Moving the scope slightly south I could fit NGC 1501 planetary nebula, which appeared unfiltered as a small, purple doughnut, not unlike M57.
Alicante 1 is a small, tight knot of faint stars, with two brighter ones framing it. I also looked at dark nebula B6, moderately dark, mainly viewable as an absence of stars or change of greyscale, a large bean shape, no clear edges.
NGC 7331 & Stephen's Quintet: Seen in the same field. 7331 was a pretty bright spike, brighter in the middle; I did not see its attendant galaxies, the "fleas." Stephan's Quintet looked like a ripple in the star field, a small cloudiness with a couple bright knots. A very unique visual view.
It seems this telescope was made to view the
California Nebula, NGC 1499. At 35x with HBeta filter, it was very large, bright, with waves and ripples flowing through the main, curved body. Each end was just outside the field of view: the NW end was stumpy, as if torn from some larger stalk, with jagged remnants left behind. The SE end was long and wispy, tapering away to the NE, before the wisps were lost to view. The northern outer curve was quite brighter, a thicker section of nebula.
Sh 2-216: I've tried for this planetary a couple of times previously, even with my 20-inch, but had failed to see it. This night I saw its brighter eastern arc. At 35x and with OIII, it was a very large, moderately faint arc covering about one quarter of what should be a round nebula. That quarter filled about one quarter of my field, so it is a very large nebula indeed. I felt some haze present in the center of the nebula within that arc. It is the second closest PNe to earth (the Helix nebula is closest, according to the latest Gaia data), which explains its size, and is likely rather old.
Simeis 147: This is the well known supernova remnant in the northeast corner of Taurus. I had tried for this before too, but given the success I seemed to be having tried this one too. At 35x and with OIII, I could see the three brighter arcs to the south west, south east, and north east (A-B-D-C as below). Actually it was fairly easy, and starting from STF 749 as a starting point could follow the counter-clockwise course with three field diameters panning of my telescope. I had the impression less of filaments than of a curved, partially degraded jet plane vapor trail. The total extent of the nebula is 3 degrees, and is about 3,000 light years away and 40,000 years old.
Comet 2020 M3 Atlas: Thanks to Akarsh and his post on TAC, as otherwise I would not have printed out comet finder charts before going out, I observed this comet. I tried for it first when Orion cleared the trees, but I could not find it -- I was searching south of Bellatrix as indicated by my chart for 11/15. Later I realized the dates were in UT, so searching to the north, at the 11/16 mark, I quickly found the comet near open cluster Do 21, and made a sketch. It was a moderately bright round hazy glow with a small non-stellar pseudo-nucleus. The halo grew in size considerably with a comet filter. About and hour later I re-observed the comet and noticed it had moved considerably far (one Do 21 width) away to the north. Now that Orion was higher the comet was better resolved: The halo was quite large, and had the same improvement with the filter, and I could see the beginnings of a tail or elongated bulge.
Many of us know there is a second open cluster, NGC 2158, near the great open cluster M35, and it is always a treat to compare the dense, round and mostly unresolved (at low power) NGC next to the bright, spangled Messier. My Interstellarum atlas, however, plotted a third open cluster, Kp 63 (Koposov 63), also on M35's boarder. Kp 63 is on the opposite side of M35's center than NGC 2158, and about half the distance from M35's center as NGC 2158's distance. Interstellarum plotted enough stars for me to star hop in the eyepiece (at 84x this time) to where the cluster should be. With averted vision I saw a faint, small chalk mark -- though whether this was in fact the cluster is probably an open question since it was discovered via a survey of infrared catalogs... Vizer gives the position as 06 10 02 +24 33 38, 5 arcmin diameter, 3000 pc distant, and in the discovery paper mag 12.32. According to the 2006 discovery paper, the authors automatically searched for star clusters "in very large stellar catalogs, which is based on convolution with density functions. We have applied this method to a subset of the Two Micron All Sky Survey catalog toward the Galactic anticenter. We also developed a method to verify whether detected stellar groups are real star clusters, which tests whether the stars that form the spatial density peak also fall onto a single isochrone in the color–magnitude diagram. By fitting an isochrone to the data, we estimate at the same time the main physical parameters of a cluster: age, distance, color excess." Why Interstellarum plots such objects, I don't know...
Abell 21, Medusa Nebula. This is another one I've tried before without success, for whatever reason. This time it was fairly large, coving half my field, rather bright kidney shaped cloud, filamentary structure running NE-SW on the inside, with brightening on the NE and SW ends. The outer edge facing SE was brighter and more defined, the inside concave curve was more diffuse. With OIII.
Perseus Galaxy Cluster: Moving the scope 2.5-degrees east of Algol, I had a fine view of the faint seam of the brightest galaxies of the Perseus Galaxy Cluster. These would be NGC 1267, 1270, 1272, 1273, 1275, and 1278 (seen with certainty), scattered like so many grains of rice, among several faint others popping into view around this string. Amazing to think how far away, and how far across, I could see with my own eye.
NGC 891 & the NGC 910 Group: Also in the same field of view. NGC 891 was fairly bright, small about a quarter of a degree, near edge-on, mottled halo. The NGC 910 group was an "S" shaped wrinkle in the star field, very faint set of out of focus faint light.
Seagull Nebula: IC 2177: This was a very interesting nebula, seen at 35x with OIII. Long bands of turbulent cloud in a generally NE-SW, long slow arc, with a bulging center, forming a seagull with wings, a little larger than my field. Several open clusters of moderate size are swept up by the wings. To the NW is a mostly round, turbulent cloud, clipped by darkness, which shows best with HBeta -- this is
Sh 2-292.
VMT 10, part of the Monoceros Loop: Irregularly shaped nebula which reminds me of a squid's head. It is pretty large, filling 2/3rds of my field, filled with very faint turbulent cloud with very faint, slightly diffuse edges. With OIII at 35x. The Monoceros Loop proper is a very large (7x9 degree!) supernova remnant which also contains the Rosette Nebula to the south and the Cone Nebula to the north. VMT 10 is a slight brightening in the overall nebulosity of the area.
Sh 2-273 & Cone Nebula: I made a good attempt at this, using 84x and HBeta. The Christmas Tree cluster NGC 2264 was very nice and a harbinger of the pleasant season approaching us. To my surprise Sh 2-273 showed up very plainly when I screwed on my filter: moderately bright with long streamers flowing at the base of the "tree" and along either side. It looked like a Christmas Tree on fire. I saw a gap in the nebula at the top of the "tree," just where the dark nebula LDN 1607 / Cone Nebula should be, but I did not see any dark nebula itself -- just the absence of the brighter nebulosity.
