by Mark Wagner
Last night (March 9), I took my 10" f/5.6 out back to cool down, owing to a very nice sky at sunset. Back indoors, I finished some late work, then began putting on the warm layers of clothes I'd need to be outside on the cold winter night.
I decided to pursue my Herschel 400 in-or-near town list, which is my latest project with the 10" Dob. The targets for the night looked to be almost exclusively open clusters in Gemini and Monoceros. Opens are good in-town targets, as their brighter components are easily detectable, and indeed, some of the dimmer associated stars glimmer in the background tantalizingly, at the edges of perception.
So, out back I went and, as I have become accustomed to, found myself staring directly at my neighbor's brightly lit kitchen window. I began to curse Mike Shade, and his reports from southern Arizona. I recalled how my backyard was an in-town observing paradise, until the neighbor's gardener destroyed my 20 foot tall oleanders with some agent orange derivative. Out front, the neighborhood, one of the safest in the city, was now sprouting garage-mounted floodlights... not motion-detectors, but flood-lights. I was feeling trapped. I have to start looking for a better place.
Still, after deciding I had to do something, I located a spot in the backyard where the lighting was not direct. What a difference 15 feet can make! By this time, overhead, just north of zenith, running northwest to southeast, was what looking like a well spread out con-trail. Amazing, one long cloud. It seemed to stay overhead, changing orientation like a spinning pointer on a board game. I thought I could work around it.
I first looked at M42. It was okay. I know I'm jaded, but I needed a bigger "kick".... since much of the nebula was just not there. I decided to check the seeing by pointing at NGC 2903 in Leo. I can usually get a definite "yes" it is there on this object, on a good night. This night, it was yes, I can barely tell I'm looking at it. So, off I went into the opens of the southern winter sky.
But first, for the record, along with the 10" f/5.6 Dob, my tools were a 20mm Nagler, yielding about 74X, a Telrad that dewed up, a pretty poor 6x30 finder, Wil Tirion's SkyAtlas 2000 and the Sky Atlas 2000.0 Companion (by Robert A. Strong). The list I was using was generated off NGP (DOS shareware) and Excel.
The first open cluster of the night was NGC 2244. Many of you know this cluster, as it is home to the Rosette Nebula. No, I didn't see the Rosette, but the cluster itself is easy to find, bright at mag 4.8 and 24' in size. It was large, and well placed in Monoceros just nearly mid-point between Betelgeuse in Orion and Canis Minor's dimmer star Gormeisa. There are some good bright guide stars nearby, so it is not difficult to locate. It felt good to find something!
There are three bright stars in the area, which describe a line right toward the eastern most bottom star in Gemini... mag 3.35 31-Xi Geminorum. Moving up toward that star, just past the middle of the three, you come across NGC2251, a rich open cluster that is very attractive. I had to keep looking at this one... it was elongated.... a beautiful condensation of stars stretched out.... glimmering at mag 7.3. This one is easy to find, and very nice to view. Worth a side-trip from the Rosette and Christmas Tree clusters that draw people to the area.
Speaking of the Christmas Tree, that was my next object. But, I noticed Hubble's Variable Nebula was in the area. In vain, I scanned over and over, but to no avail. Looking up, I noticed the sky was now becoming milky. Hey, what is this, are my 15 minutes of observing this month up already? ;-)
But NGC 2264, the Christmas Tree, was so bright there was no trouble finding it. It is very large, according to my atlas's companion, it measured 35'x15'. On a dark night with good aperture, at the right location, I'd be hunting the Cone Nebula during the visit. The cluster is mag 3.9, and very easy to see. Doing a bit of reading, I noted that the age of this star group is thought to be 20 million years. A mere pup. I could not help but relate that to NGC 2903, the galaxy in Leo that I looked at early during the observing session. The light I saw from that galaxy traveled 20 million years before striking my eye. NGC 2264 was just being born when the light from NGC 2903 began its journey to my eye.
Looking up again, I thought the sky was improving. I pointed the scope back up at the Leo galaxy, and no doubt, there was a nice form to the object. I could tell the morphology (of course, it helps to know in advance what it looks like.
So, I went after the next object on my list, NGC 2286. All I can say is, find this object. It is gorgeous! Hard to believe I'm so excited about open clusters, but really, after a while their personalities, the shapes, the subtleties, began to come out. This cluster is listed as moderately rich, but not well detached from the surrounding star field, with a large range in brightness. It is mag 7.5 and is compressed. It sure does not look like much in photos, but I was quite taken with it. It was not difficult to find either, and in fact, due to dew on my Telrad, I used the 6x30 to sight in a wide group of fairly bright stars nearly halfway between Sirius and the previously mentioned star at the base of Gemini. This method of "locating" will almost drop you on the object!
Now, the sky was getting milky again. I was having trouble seeing the star in Gemini. I became disoriented and began using Procyon instead, which made finding NGC 2301 impossible. Finally, I realized I was looking in the wrong place. I used the optical finder to located my friendly star in Gemini, and soon was on the cluster. NGC 2301 is a dense cluster. It is fairly bright with a wide range in brightness among its components. I like this, as, with some study, the fainter components begin to shimmer in... I keep relating the appearance to the very first hints of frost on a window in winter. But, moving the scope and averting vision, you know there are dozens or hundreds of stars mixed in with the big bright ones. Interestingly, my computer planetarium program says the size is 12', while the atlas companion says 6'. I thought is was larger than either of those figures. As I recall, this object also has an unusual shape, giving it a striking appearance.
By now, the sky was really getting bad. It was whole milk, and I was feeling some intolerance. But, for one last object, I tried, and tried, and tried NGC 2304 in Gemini. This one is in Gemini, just south of the line described between Alhena and Mekbuda, the inner leg of the eastern twin (Pollux's leg). The atlas companion list this item as mag 10, my printout says dimmer than mag 11. It is also small at about 5'. The cluster's lack of density also did not help. I spent about 20 minutes, maybe more, checking and rechecking charts, but, although I thought I detected it that night, I now think not. Maybe next time.
Looking up, frustrated at the sky, I decided to pack it in. All in all, it was good to just be out in the cold crisp air, with nothing but the stars and my scope as company.