Now that the November blahs have hit us in the northern latitudes, there will be plenty of time to reflect on all the wonderful observing done over the past summer and early autumn. Tolkien calls the time between Nov. 1st and Dec. 21st "The Fading," an apt name. I have yet, in all my years of observing, to have a banner observing month in November. It's mostly overcast, windy, cold, and the leaves are down, giving the sky and stray lights too much glow. However, there is always hope for this November. We shall see. With the moon waxing now, there is still time to reflect.
After a spring session in which I observed literally nothing but galaxies (Leo and then Bootes), it was a real treat to begin studies of Aquila in early July. To see a quick overview of what objects are in this constellation, see the blog entry for July 27th, 2014. Observed in previous years with the 8", there were some new NGC objects for me, along with clusters from other catalogues. I was also looking forward to seeing again what I had seen so many years ago with my previous scope.
pn 6751 (26"; V. 11.9; Cent. * 15.4) was located easily, between two faint stars, and viewed up to 300x. It has a very bright, star-like middle section, with an occasional hint of a dark cneter and/or dark lane. This object is small but impressively bright.
oc 6735 (8'; 35 *s; Br. * mag. 12) was a new one for me, and it was observed on the night of July 3rd. It was my first cluster in several months. Looking at Uranometria, I was expecting a mag. 7 star to mostly drown out the faint cluster members that apparently surrounded it. Instead, I was pleasantly surprised, even at 60x! Here lies a lovely and busy cluster of faint stars surrounding a bright yellow star, but they are hardly drowned out by that object's light. Best seen at 100x, the cluster drifts west from the yellow star (preceding). At 125x I counted at least 50 stars. It even looked decent in Deb's 6" mirror at 94x.
Aquila has a number of stellar-like planetary nebulaes. Outside of NGC planetaries, I rarely seek out these objects from other catalogues. The following objects were observed the night of July 4th.
pn 6741 (8"; V. 11.5 mag.; Cent. * 20.3 mag.) showed a very small greyish-blue disc at 375x. It has a close, very faint stellar companion. It can be found just following oc 6735.
pn 6741 (8"; V. 11.5 mag.; Cent. * 20.3 mag.) showed a very small greyish-blue disc at 375x. It has a close, very faint stellar companion. It can be found just following oc 6735.
gc 6760 (9'; V 9 mag.; Br * 15.6) was next, easily spotted at 60x. Compared to the dozens of faint galaxies I had recently viewed, this was an easy and fun object to observe. Despite appearing as if it will resolve at any moment, it doesn't. I viewed it up to 250x, where it at last begins to resolve, but only outside of the central core, which is still very bright and still blazes. It glows from within like some mysterious lamp, bright as can be but hiding its stars.
Another new NGC object for me was gc 6749 (4'; V. 12.4 mag.; Br * 16.5 mag.). This is unlikely to be the object first reported by Herschel, as it is much too faint. Despite this, it is now accepted as 6749. Lying in a very rich area of the Milky Way, it has a very low surface brightness and is essentially very faint haze tucked in behind 3 or 4 mag. 12 stars. There might be work to do here with a larger scope, but a 12" barely shows the haze if you have a pinpoint location.
Two faint Berkeley clusters were next, Be 79 (7'; Br. * 15 mag; 60 *s) and Be 80 (3'; Br * 15; 20 *s). 79 was large and somewhat circular. Noticed at 100x, using up to 200x resolves about 15 very faint stars. The "brighter" members were clustered towards a mag. 9 star. It resolves only with averted vision and high power. 80 was located at 60x, but it was only a faint, small hazy patch. It is much easier to see than gc 6749! Up to 250x was used to resolve a very faint E/W string of 6 to 8 stars, using a.v.
I will conclude Part 1 of Aquila with a pair of open clusters, observed on July 17th.
oc 6755 (15'; V. 7.5 mag.; Br * 11 mag; 157 *s) is an unusual cluster. Ringed by bright members, there are three separate very dense sections. In the extreme S was the smallest knot. The largest was central. N was a 3rd group, less rich than the central one. A bright member is preceding the central group, with a faint double star just S of it. At 60x the cluster was mostly haze, which is large and quite spread out. The area including the central clump contains about 50 stars, while the N group has about 25. Up to 200x was used to resolve and scan the cluster. It looked good in the 6" as well.
oc 6756 (4'; V 10.6 mag.; B * 13 mag; 40 *s) is just north following, and in the same low power field. This tiny, faint group resembles a globular cluster at 60x. However, 187x to 300x resolves the dense central group. About 15 stars were counted in and near the main group. It is bright enough to use 300x, which is recommended to really get inside this little cluster.
I will be back soon with Part 2 to Aquila, and then I will continue on with Delphinus and Sagitta, two other constellations I managed to begin and complete over the summer.
Mapman Mike
