Last night I hauled out my 10" f/5.6 Dob to take advantage of a clear night. I have addressed the neighbor's curtainless kitchen window pouring light directly into my backyard by purchasing a few 6' pieces of PVC, tarp, mounting brackets and wood blocks, to construct a night time light blind. It worked *very* well! Unfortunately, the work the neighbors just completed on their home included redoing their backyard, including some new bright lights. It is strange to see one half my yard in daylight, one half in night's darkness, but that is something now possible at my house. Win some, lose some. :-(
Still, I had a *great* night, barefoot next to the swimming pool, in shorts and t-shirt, from 9:30 until 11:30. I was planning to try for some dimmer objects from an in town site (my Los Gatos backyard). I had used the DOS freeware program NGP (excellent program!) to sort objects in descending order from mag 10 to mag 12, by constellation. I had previously limited myself to mag 10 and brighter, but Randy Muller's reports from the Sacto area convinced me I should be looking deeper. Tonight, Canes Venatici was just past zenith at dark, and would provide plenty of challenge.
I started off using the Alpha and Beta stars as my reference point. Alpha is Cor Caroli, Beta is Chara. The first target was NGC 4214, but that would not be the first NGC I'd find. I began by drawing an imaginary line from Cor Caroli to Chara, then taking half the distance I had "travelled" and going that much in a direction away from the handle of the Big Dipper. This would place me on SAO 63000, my jumping off point into telescopic star hopping. Man, is this stuff FUN to do!
From the star I moved in the same direction, away from Beta to find a line of three stars, two being almost equal mag, the third being dimmer. I moved the direction the brighter two pointed, until I came upon a bright wide pair of stars. That had me close to NGC 4244, on the way to 4214. Looking at my Tirion 2000 and home-made Uranometria type charts, I could see that by moving along the line these two stars pointed, again, away from where I had come, I would have an empty field or so, then a group of several dim stars. True to the charts, I was there. But where is the galaxy? I looked for a while, then it clicked in, a long slim streak of gray brightening laying in the same direction I had come from , but off to one side. This was a large galaxy! It was possible to hold it with direct vision, but it shone more easily averted. What a great sight! Specifics (from The Sky by Software Bisque):
Edge on galaxy.
Dreyer Descr. PB,VL,EE43,VGBM
RA, Dec: 12h 17m 25.8s , 37d 49m 30s N
Az, Alt: 285d 44m 17s , 52d 44m 32s N
Size (mins) 16.0 x 1.8
Big, eh? :-)
Now, knowing exactly where I was became a big asset in continuing on to locate my initial target, 4214. I could see on my chart that 4244 pointed toward a pair of stars that would be perpendicular to my direction of travel, and they would be reasonably bright compared to the others I'd see in the process. So I moved until the stars appeared. These in turn pointed right at 4214. A quick jog to that side, and there was the galaxy. This galaxy appeared in the eyepiece to possibly be a nice spiral, tilted toward/away from us, having a bright core that diffuses out evenly. 4214 seems to be about half the size of 4244, but is much brighter. Specs:
Spiral galaxy structure.
Dreyer Descr. CB,CL,IE,BIN
RA, Dec: 12h 15m 32.6s , 36d 20m 30s N
Az, Alt: 283d 33m 30s , 51d 59m 13s N
Size (mins) 7.5 x 6.0
Hey! I was pretty close on the size difference!
Now I was convinced that I could go deeper on the NGP generated lists. But strangely, NGP lists 4214 as mag 10.5, meaning it was anywhere from 10.5 to 10.99, since the NPG uses half-mag increments, and The Sky shows mag 9.69. I can't get over these differences!
The next object, NGC 4449, should have been easy. This is a lesson in "no matter how much one observes, there is always room for bonehead mistakes" and I did one here. To get to 4449, take Cor Caroli and draw a line to Chara. Proceed in the same direction past Chara and you will unavoidably hit (not literally) NGC 4490. Angle ever so slightly toward the Big Dipper here, and you will soon run into a group of five stars. Two are paired on the side you approach from, the other three are in an arc on the far side of the field of view, with the dimmest of the three stars close to the initial two star pair. I confused the "wide" end of the three star arc, because there were other stars in the field and I was not careful enough studying the chart. I could not understand how I would move away from the Big Dipper to get to 4449, but that's what I kept trying to do. After about 20 minutes, I realized my mistake. The two stars at the open end of the five star asterism pointed to another bright star, which had an equally bright pair. Those two pointed directly at NGC 4449, equidistant away from the pair. This galaxy sits alone, in an area of few stars. However, it is bright and appears to be a tilted spiral with a very bright core, some possible dust mottling, and takes up about one quarter of the field in the 19 Panoptic I would use exclusively (75X). Nice find!
Elongated galaxy with bright core.
Dreyer Descr. VB,CL,ME,DORBIFID,*F
RA, Dec: 12h 28m 7.8s , 44d 6m 30s N
Az, Alt: 295d 47m 33s , 55d 46m 8s N
Size (mins) 5.5 x 4.5
Next target was NGC 5033, very close to NGC 5005. These galaxies were on the other side of Cor Caroli on the line between it and Chara. This too proved difficult. I was having trouble with the star fields, which convinced me to finally put an optical finder on my 10" (which I did today), in order to get a better view in light polluted skies. Anyway... the galaxy... To get to 5033, it is best to go along the previously described line away from Alpha, and slightly toward the handle of the Dipper, until you come across several bright stars. These are very close to 5005. In fact, there are three stars in the bright grouping that point right toward 5005. Continue past 5005 to a dim pair of doubles. Off the dimmer of the doubles is the galaxy 5033. Looked like it was good size, with a bright core:
Very elongated galaxy with bright core.
Dreyer Descr. VB,PL,E167,SMBMVBN
RA, Dec: 13h 13m 19.8s , 36d 36m 29s N
Az, Alt: 278d 46m 28s , 63d 19m 6s N
Size (mins) 10.0 x 4.0
My feet were getting cool on the wet wood deck and concrete. My kids and dog were in the pool until just before sunset, and now I had the leftover out of pool water to stand in. So, I made a "flavored" coffee and took a short break.
On to NGC 4490, next target. This object would test the night for limiting magnitude naked eye. I had to find SAO 63070, a mag 5.4 star, in order to know where to turn to get to the galaxy. With averted vision, the star was definitely there. Not the best night, but not too bad from in town! :-)
The star was at right angle to the line between Cor Caroli and Chara, on the Alpha side, and away from the handle of the dipper. If the distance between Alpha and Beta is 5 degrees, the distance from Alpha to the target star was just a bit longer, maybe 6 degrees. Once there, I moved away from the bowl of the dipper by using SAO 63072 and SAO 63046 to determine direction. Before I knew it, I was on 4656. What a monster this galaxy is! I could hardly believe it! It took up well over half the field of view, and was very close to another large galaxy NGC 4631, which I came upon going to 4656. I have to see this galaxy in Big Ap and dark skies! Killer views - perhaps a tilted spiral with a large and elongated bulge.
Very elongated galaxy close companion.
Dreyer Descr. PB,L,VME34,SPOF2
RA, Dec: 12h 43m 55.8s , 32d 10m 29s N
Size (mins) 20.0 x 2.5
At this point, fatigue, special coffee, cool feet and Canes Venatici dropping lower toward the soup all conspired to make me quit observing for the night. I had been trying to find NGC 4145, but was having difficulty. And, if the weather held, I would be out the next night to get a fresh start.
What a nice night, barefoot out in my backyard. Sure feels like the tide has turned on the weather!