FUZZY SPOT, August 2001, Aquila
This month's constellation is Aquila, the Eagle. It is one of the oldest constellations in the sky, inherited by the ancient Greeks from the older cultures of the Mesopotamians, Babylonians, and Sumerians. The brightest star, Altar, is the head of the eagle. It is also one of the stars in the Summer Triangle, along with Vega and Deneb.
Although it sits squarely on the Milky Way, it is poor in objects, especially for its size. The reason for the is that the very opaque Great Rift blocks many of the objects that reside along the disk of the Milky Way. This leaves us with a few open clusters and planetary nebula, and one very nice globular cluster.
NGC 6709 (18h51.5 +10 21) In the 10" scope at 100X, this open cluster is very bright, very large, and not condensed. There are about 3 levels of stars with some possible background haze, and a total count of about 50 stars. The brightest stars form a triangle, and there is a nice blue/yellow double on the ENE side. This is a nice large bright cluster. Why this cluster is not in the Herschel 400 and the other 2 dinky ones are, I dont know, I guess Herschel didn't observe this object.
NGC 6751 (19h05.9 -06 00) In the 10" scope at 360X, this planetary nebula is somewhat bright, pretty small, and slightly elongated E/W. There is a bright star way off to the E and a fainter star just off to E which may be involved. I could not see color in the nebulosity at any power. Using the UHC filter does not do much. In the 20" scope at 180X, it is somewhat bright, a little small, round, and may possibly be mottled. The central star is seen about 20% of the time. The nebula responds quite well to the O-III filter, but the filter does not add any more detail or increase the size. To WNW is V Aquila, a very beautiful orange star.
NGC 6755 (19h07.8 +04 14) This open cluster is not too big, and contains 22 stars over some haze in two groups. The S group has more stars, I counted 15, while the N group contains only 7. Increasing the power does not resolve any more stars.
NGC 6756 (19h08.7 +04 41) The neighboring cluster to 6755 is pretty obvious in the 10" scope, somewhat bright, and pretty condensed. I was able to resolve perhaps 9 stars over some haze.
NGC 6760 (19h11.2 +01 02) This is a nice globular cluster, seen in the 10" scope as not too big, somewhat bright, round, and gradually brightening to the middle. It is very grainy, particularly in the halo. Using averted vision makes some of the stars pop out. Increasing the aperture really helps with this globular. In the 20" scope, it is pretty bright and pretty large. The halo is a very granular haze which evenly brightens up to the middle. When seeing holds steady, many stars resolve into a beautiful multi-points of light. The middle is round, but the outer part appears triangular with averted vision. Very nice!
NGC 6781 (19h18.5 +06 32) To observe this planetary nebula, use a UHC filter, it really helps bring the object out. At 100X, it is pretty bright (even without the filter), pretty large, round, and contains one or two dark spots in the middle. No color is seen, with or without the filter.
NGC 6804 (19h31.6 +09 13) The final planetary nebula is seen in the 10" scope as slightly bright, somewhat small, and situated between 2 stars in the base of an isosceles triangle. The UHC filter doesnt do too much, but using averted vision does make it grow somewhat, appearing elongated E/W. On the E side there is a star involved, on the WSW side is a star just out of the nebulosity. In the 20" scope, it is a little small, somewhat bright, and irregularly round. 2 stars are involved with a third suspected. A star to the NW is red. There is a possible annularity seen with the filter. Very nice, seen as a small puff of smoke in a rich star field.
Herschel 400 Objects
6755, 6756, 6781
SACs 110 Best of the NGC Objects