Bright stars seemed to twinkle frantically as dark set in. I put my 10" f/5.6 Dob and Equatorial Platform outside to cool down and left it to cool down for an hour. Walking outside at 9:30 p.m., the sky was bright. I could barely see the Milky Way... I think it was mostly imagination, knowing where to look. Saggita and Delphinus were both barely showing, a measure of how bright the sky was, probably due to pollutants (other than light).
I went through portions of the Herschel 400 list, which I use for backyard observing. I looked for targets on my list and saw if they were included in any of the Astro Cards. With 20mm Nagler in the focuser, I was at 71X, quite a bit lower power than I am accustomed to. Still, the view through the 20 is spectacular. The only other eyepiece I would use during the night was the 12 Nagler, a jump up to 118X. I also used a Telrad and University Optics 11x70 finder, along with Lumicon's UHC and OIII and Orion's Ultrablock filters.
As you can see by the list below, even in an suburban backyard, with a bright(ish) sky, deep sky observing is possible, and in fact, enjoyable.
NGC 6781, mag 12.0, 1.8', in Aquila is a smallish planetary nebula. I suspected it without a filter, but upon installing the UHC it was an easy target. Although it is described as a "planetary ring" I saw no evidence of a ring, just a fairly solid circle. The object is easy to locate, one third the distance between Delta and Zeta Aquilae.
NGC 6755, mag 7.5, 15.0'. This cluster appeared as a change in contrast, a slight hazy brightening, in a fairly rich Milky Way star field. It was decent size, but otherwise non-descript.
NGC 6756, mag 11.0, 4', appeared as a small "frosty" glow. Not much too this open cluster in suburban skies. I used the stars Delta Aquilae and 63-Theta1 Serpentis as guides, with the cluster being slightly toward Theta on that line.
NGC 6802, mag 8.8, 3.0' in Vulpecula is a cool open cluster! Near "The Coathanger" (naked eye cluster) it sits just east of and about mid-point between Zeta Aquilae and Beta Cygni. The Astro Cards provided a very nice hop to this object. the cluster appears small, dim, and looked like an unresolved globular cluster. The Equatorial Platform helped greatly in identifying this object, as I was able to spend time back and forth at the charts without any drifting. Two tight doubles sit on either side (off-line), both doubles have equal separations and distance from the cluster.
NGC 6820, low surface brightness nebula, 40' in Vulpecula is perhaps barely detectable from my backyard. This looks like a fun target for a dark sky site. I found perhaps two dozen stars in a faint, hazy, emission nebula. It was large, and seemed centered (at least what was the brightest or most visible section) outside two almost parallel chains of stars, outside the wide end of the chains. To locate this position, I star hopped in my finder, starting at Alpha Vulpeculae. The parallel chains of stars identified the place to look. I may try this again tonight with a filter (doh!).
NGC 6823, mag 7.1, 12' in Vulpecula. This cluster is a nice sight, with about two dozen stars, and sits in the center of the nebula NGC 6820. Again, this may be a fine sight in a dark sky. Check it out!
NGC 6834, mag 7.8, 5.0', in Cygnus. Small, compact open cluster, dim haze. There are bright stars in the center of this cluster. Located east of the line between Alberio and Eta Cygni, rather difficult to hop to.
NGC 6866, mag 7.6, 7.0' in Cygnus. This open cluster is as easy to find as NGC 6834 was difficult. Naked eye stars 31 and 32 Cygni can be pointers to the approximate area, just NW of the center point between Gamma and Delta Cygni. I dropped right on this object with only the Telrad. This is a nice compact open cluster with many stars, easy to identify. A chain of bright stars traverses the cluster from north to south.
NGC 6910, mag 7.4, 8.0' in Cygnus. If NGC 6866 was easy to find, this open cluster almost hands itself to you, it is so easy sitting just over 2 degrees north of Gamma Cygni. About 10 stars appear to populate the brighter components, forming a long "Y" (kind of, sort of). Two stars in the Y are brighter than all the others. The cluster is spread out, but still is a pleasing grouping.
NGC 6934, mag 8.9, 5.9' in Delphinus. I've visited this smallish unresolved globular cluster many times before, due to its easy location. Looking at the "Dolphin" one can follow the arc of its tail from the back of the diamond "body" almost precisely to the correct location. The globular, while a poor cousin of the big bright Messier globulars, is still a pleasing find, and unmistakable as a globular cluster. A bright star sits close by to the object's west, with two more stars still further to the west.
NGC 6940, mag 6.3, 31' in Vulpecula. I was surprised to find how large the constellation Vulpecula is. This object is toward the Veil Nebula, a favorite object for amateur astronomers. Two stars point at this open cluster... travel an equal distance away from Cygnus, using 39 and 41 Cygni as your naked eye guide stars. You'll drop right on the cluster. This open is drop dead gorgeous! Big, bright, rich with a stream of stars from the north west to the south east. This one could have easily replaced some of the tiny Messier open clusters! A real treat.
NGC 7006, mag 10.6, 2.8' in Delphinus. Remember how to get to NGC 6934, the globular two objects back? This one is kind of a twin, as far as how to find it. Using the center star in the diamond (the dolphin's back), traverse to the snout, then a little more than the same distance beyond in the same direction. This globular cluster is more of a challenge, dimmer, smaller, and definitely unresolved. At 74x with the 20 Nagler, a bright star sat halfway to the western edge of the field.
NGC 7008, mag 13.0, 1.4' in Cygnus. This one is barely in Cygnus, but is a remarkable object worth hunting down. Use Deneb (Alpha Cygni) and Alpha Cephei (Alderamin) as the guide stars. Place the southern outer ring of a Telrad circle on the center point between the two stars, you should be close to NGC 7008. This planetary nebula is so interesting, I visited it again the next night. Here are the two night's descriptions:
7/18: planetary nebula, fairly bright, largish, bi-lobed? Bright star to south, very close. North edge brighter than south. Interesting object.
7/19: 12mm Nagler with Orion Ultrablock filter. Cool object! Bright, perhaps annular and elongated slightly NNE-SSW. Very bright knot on the northern edge. Pair of stars almost toughing the souther edge. Needs more magnification and a darker sky.
The next night I was out again, but that write-up will need to wait.
It was a nice, but bright night in my backyard. I still got in some very enjoyable observing.
|Location||Los Gatos, California (37:13:36N 121:58:25W)|
|Scope||10" f/5.6 Dob on an Equatorial Platform|
|Eyepieces||20mm and 12mm Nagler Type II|
|Filters||Lumicon UHC, Orion Ultrablock|
|Finders||Telrad, University Optics 11x70|
|Time||9:30 to 11;30 p.m. PDT|