Sunday, November 7, 2010

Southern galaxies, northern nebulae

Last night was one of the clearest, and driest nights to come along in months. After arriving at the site before sunset and setting up my 10-inch or 25cm Dobsonian telescope, a friend and her family came visiting along with folks who own and fly aircraft out of the airstrip where I observe. Once it became dark, I gave a tour of some of the better show piece objects for them such as the Andromeda Galaxy, Dumbbell, Veil and Swan Nebulas. These are all spectacular through smaller telescopes if the moon is absent and the sky free of haze and heavy light pollution. The airstrip I use as an observing site is at most thirty kilometers from the edge of my city, and therefore subject to quite a bit of light pollution. However, the Milky Way was plainly visible and numerous stars were in evidence except near the light domes from my city and others that surround the area. I also assisted my friend with her telescope, and looked though it as well. The air temperature fell swiftly after sunset, and it soon grew cold, enough that I bundled up under a heavy German army field jacket after they went home and got down to the business I came there to accomplish, observing and sketching galaxies and nebulae visible through my telescopes. Dew was mercifully minimal but the seeing was turbulent. Stars often appeared as fat blobs and they twinkled furiously near the horizon. At least the wind was light and few clouds existed to spoil the view, and the cold was tolerable.

First on my list was the Pegasus galaxy NGC-7814, a precisely edge on spiral galaxy that has a very thin dust lane along it's length. However, it did not appear and the galaxy itself was a softly glowing object shaped rather like a double convex lens turned edgewise at 150X

Next was the large and fairly faint Cetus galaxy NGC-908, a very large spiral galaxy that appeared as a dimly glowing oval glow that was vaguely patchy with a brighter center at 150X. A trapezoidal formation of foreground stars lied along one side. It was an easy object, comparable to some of the dimmer Messier galaxies in fact, but not as well known as they are.

The next object to be observed was the small and face-on spiral galaxy NGC-309, which at 188X has a slightly brighter core. No sign of the spiral arms was seen, but it was fairly easy to find and fairly bright despite the low elevation it has from my area.

Next was the spiral galaxy NGC-428, a massive spiral galaxy 70 million light years way that just finished merging with and absorbing another smaller galaxy. It showed no sign of the peculiar split spiral arm at 188X that is plainly apparent in photographs, but it did show the prominent nuclear region. This galaxy resides in a perfect right triangle of foreground stars, like a diamond set on a ring. No doubt a larger telescope will show hints of it's disturbed structure at a dark site. It's galaxies like this one that led to my efforts to build a much larger telescope to better see them.

A short distance away can be found the elliptical galaxy NGC-430, which was flanked by two smaller and dimmer elliptical and lenticular galaxies at 188X. NGC-430 was small, faint and round with a bright core, whereas the other two were dimly visible with averted vision. NGC 426 is also small, oval and has a brighter center, while NGC-429 is more lens shaped with a brighter core. The trio makes up an isosceles triangle with the lenticular galaxy being canted at an angle that points away from the longest side of the formation, with NGC-430 being the brightest member of this small galaxy group.

A short hop led me to another Cetus galaxy, NGC-448. This object was bright and very elongated oval that has a very bright core at 188X.

Along the way, I paid a visit to several galaxies in the southern constellation Sculptor. First and foremost I stopped to look at NGC-253, the largest and brightest of the Sculptor Group, which consists mostly of more than two dozen spiral and irregular galaxies spread across 20 degrees of the southern skies. NGC-253 itself is known as the Silver Coin Galaxy. Very bright and nearly edge on, this galaxy has shown hints of the dark dust clouds that litter it's disk from very dark sites through my 10-inch. At 63x it spanned a greater length than the Moon. More than ten degrees farther south led me to another large member of the Sculptor Group, NGC-55. This is an edge-on irregular or barred spiral galaxy that appears as a patchy, long and very  bright streak, again at 63X. These are among the closest galaxies to us outside of our Local Group, but they are very low in the sky even from the southern United States. For people in the southern hemisphere, they are among the brightest and most spectacular galaxies in the skies visible to them. Even a 6-inch or 15 centimeter aperture telescope at my location has no problems revealing them.

Then I turned to NGC-289, a galaxy that is much father away than the Sculptor Group and is therefore a background system. It's bright inner core was surrounded by the much dimmer spiral arms of this oval galaxy at 188X. Another oval galaxy with a brighter center was the very patchy NGC-7793, which displayed a large oval disk at 150X. Subtle patchiness was seen intermittently in this nearly face-on spiral galaxy.

Before packing up for the night and returning home, I looked for and found the reflection and emission nebula NGC-1579 in Perseus. This object apparently demands very clear skies to be seen, because it eluded detection until now. It's patchy and irregular form was easy to spot even at low power. While an Oxygen III filter obliterated it from view, it showed up easily with no filter and was a nice sight at 150X.

Other objects along the way that were visited included the companions to the Andromeda Galaxy M-32, M-110 and NGC-185 in Cassiopeia. The galaxy NGC-7331 was a small but bright object that is a twin to M-31, but more than twenty times farther away from us. The other large spiral galaxy in our Local Group, M-33 was also observed, though it's dim glow is not as easy to see as M-31's.  Other bright objects I looked at included Orion Nebula and the planetary nebulae M-57 in Lyra, NGC-7008, NGC-7048 and NGC-6826 in Cygnus were also observed. Two others I stopped to look at were NGC-7009 and NGC-7293, also known as the Saturn and Helix Nebulas were also visited. The bright globular and open star clusters M-2, M-15, the Double Cluster and NGC-6709 in Aquila were also showcase objects.