Object name: IC2132

Designation(s): NGC1954, NGC 1957, IC2132,

NGC 1954 is a galaxy in Lepus I had to image for two reasons. One it is neat, and secondly or maybe primarily I finished building my first telescope in March of 1954 (started in 1953), a 6\" f/12 scope which I still have over 60 years later. It turned out to be a superb planetary scope with optics Bob Cox (he did the optics for Mercury and Gemini and edited the Gleanings for ATM\'s column in Sky and Telescope for years) described as \"Approach the eyepiece carefully lest you cut your eye on the image.\" It started me down this long road. I\'m glad NGC 1954 is a very interesting galaxy. The MCG says of it: \"Two extremely thin arcs do not appear as spirals, nor as dense rings. They consist of 15 to 20 HII regions.\" Indeed the outer arcs seem totally unrelated to the spiral structure. Unfortunately, it hasn\'t been studied that I found so I don\'t have an explanation for how it looks like it was assembled from parts of 2 different galaxies. Maybe it was, I just don\'t know. Could the arcs be a \"polar ring\" like structure? I doubt it but...

It is part of the triple galaxy system of HDCE 0361. The other two members being NGC 1957 and the \"red and dead\" IC 2132. All have a redshift distance of about 150 million light-years. This system is located at -14 degrees making it very difficult from my latitude. I\'ve had it on my to-do list from day one but no night was good enough to do it justice until I gave up and took it anyway on February 1st. It has been a really cold but cloudy day snowing until after dark. Suddenly the snow stopped. NGC 1954 was barely within one hour of the meridian, my limit at this declination. Without waiting for the scope to cool down I started in on it as this was the best (not great) night for this galaxy I\'d had since building the observatory 8 years ago. Since the clouds could return any minute or seeing go bad I took the L data. That resulted in tube currents that turned the bottom of the stars all wonky. It didn\'t hurt the resolution of the galaxy significantly, however. This low I can only image east of the meridian due to my Meridian Tree that blocks things about 10 minutes before I reach the meridian from the east side and everything for an hour and a half beyond the meridian to the west. Thus I took the color data a different night. seeing was much worse but no tube currents. That meant the wonky points had no color so I blurred the brighter stars on the color image to cover the \"points\" in the luminance image. Otherwise, those colorless points looked even worse. There are techniques for rounding the stars but I took the easy route and left the \"points\" in. It never was steady enough to reshoot the luminance as it soon was too far west and lost in the Meridian Tree.

NGC 1954 is classified as SA(rs)bc pec by NED and simply Sc by the NGC project. NGC 1957 is listed as SB(rs:)0- by NED and E by the NGC Project. As a ring structure is seen faintly I\'ll have to go with NED on this one. IC 2132 is listed at NED as Sa pec: It is an example of what now is known as red and dead galaxies due to their lack of recent star formation. About all the remaining stars are old red stars and a few red giants, the last of the more massive stars. Thus its spiral structure is quite muted. Oddly it seems to have a strong dust lane but for some reason, that isn\'t forming stars or if it is they are hidden behind the dust. It is a strong IR emitting galaxy as it is listed in the 2MASS survey. That could be due to hot new stars heating dust that emits in the IR part of the spectrum.

NGC 1954 is a huge galaxy. Measuring from the northwestern tip that extends beyond a faint background galaxy to the southeastern tip that seems to turn back on itself, it is 315 seconds of arc long. That makes it some 229,000 light-years in size! Another reason to wonder if this isn\'t due to the combining of two different galaxies. By comparison, NGC 1957 (should it look like a Chevy?) is only 43,000 light-years across and IC 3132 83,000 light-years in diameter. Large but not unusually so.

Only two other galaxies in the image had redshift data. That put those two far beyond HDCE 0361. Both are shown in the annotated image. A dozen or so galaxies from the 2MASS are also listed at NED, I\'ve noted a couple of them. One is also an X-ray source so likely is hiding something very hot behind its red glow. Unfortunately, I couldn\'t find anything on it. I noted it on the annotated image southwest of NGC 1954. A couple of galaxies that looked interesting to me but were not in NED are marked with question marks. Most of the galaxies in the field didn\'t have enough IR to make the 2MASS so didn\'t make it into NED, including one seen at the north end of NGC 1954.

So while NGC 1954 is a very strange galaxy Arp might have included in his Atlas there\'s just not much at all on the entire field. Maybe someone will eventually study at least NGC 1954.

NGC 1954 was discovered by William Herschel on December 14, 1786. It isn\'t in either H400 project.
NGC 1957 was discovered by Francis Leavenworth on December 11, 1885.
IC 2132 was discovered by Herbert Howe on February 22, 1898.

14\" LX200R @ f/10, L=4x10\' RGB=2x10\' STL-11000XM, Paramount ME