The first night was supposed to have the possibility of average transparency and seeing, at least that is the line my forecasting sites were trying to sell. An interesting aside to this whole ordeal is that I found out (by holding the wrong end of the stick) that since my last trip over in June, some yellow jacket wasps had decided to build nests in a couple of places. The main one was under the cap of one of our propane tanks off the side of the garage, next to where I observe. I typically stage stuff there, leaning tables and such against the tanks until I set it all up, banging the tanks as I do. So you can well imagine what the wasps thought of that!
Anyway, I got zapped a couple of times on my arms before I realized what the crap was going on. Watching their comings and goings I was able to extract the stuff I had placed there and move them elsewhere for staging without further pain. I then hopped in the truck and made the one mile drive to the store and bought a can of hornet-wasp spray. The battle began shortly thereafter. I did not get all of them, but the next morning bodies were everywhere with a few buzzing around. I was able to put a direct shot into the nest opening and will wait to see what is going on later in the day. My plan is to remove the nest once I am certain it is caput! The second nest is in a bush outside the kitchen windows. I was able to place a shot of spray into the next doorway and will monitor/remove it as well. Oh the joys of country life!
So that bit of insect warfare was not a good sign, and as it turned out, the evening was a bit off kilter as well. The forecast for average transparency/seeing was anything but. The primary band of the Milky Way is typically robust from Perseus all the way through Scorpius on a typical night. This night it was kind of pathetic. Not much was seen until one reached the area of Deneb, then it was faded across the sky into Sagittarius. The steam from the “teapot”, which is normally bold and eye catching, was more of a breath of a mirror. Side extensions into Lyra were non-existent to the eye. The Great Rift, while seen, was of low contrast. So after the wasp fest, the dinginess of the sky was a bit of a letdown. On the fly I abandoned my planned galaxy hunting expedition, and decided to revisit some globular clusters. With a few exceptions the ones I pursued I had not observed in years, so I thought it would be fun to return to the scenes of those past crimes!
So with that, let’s move on to my leisurely couple of hours of wandering about a below average country sky. (Equipment used)
17.5 inch
Ethos 13mm (152x, 0.7° TFOV, 2.9mm exit pupil)
XW 10mm (199x, 0.4° TFOV, 2.2mm exit pupil)
XW 7mm (283x, 0.2° TFOV, 1.6mm exit pupil)
I headed to the celestial scorpion to begin this little journey. Swinging the big
Less than 1° southwest of the previous cluster I easily scooped up this behemoth. At 152x it was a very large and very bright roundish stellar field. Countless stars were resolved across its dimension, with a very noticeable strand bisecting the cluster’s center. A few “spiral arms” of stars seemed to curve outward from the cluster’s core giving it a vague pinwheel impression. I also viewed it at 199x and it was simply stunning. It was bountifully resolved, yet presented some diffuse density within the central core. At a distance of about 7,200 LY, it is the closest globular to our solar system, and the first in which individual stars were seen. Discovered in 1745 by Philippe de Chéseaux, it was also independently discovered by Nicolas-Louis de Lacaille in 1752 and again by
Moving up to Sigma Scorpii (mag 2.9), I nudged NNW not quite 3° to easily find another from the catalogue of Charles
It had been about nine years since I last observed this object, so I decided to pay it a visit. While I have observed both M13 and M92 at various times over the years, I had not done so with this cluster. The scope was pointed at mag 3.8 Tau Herculis, and then I followed the line from mag 4.2 Phi Herculis through Tau to the northeast, stopping at 42 Herculis (mag 4.9). In the
I next moved into the celestial Dolphin, aiming the scope at mag 4.0 Epsilon Delphini (Aldufin). Nudging SSE almost 4° I easily spotted this globular using 152x. Visually it was slightly small but bright. Rounded in shape it contained a broadly brighter core set within a grainy outer halo. As seeing shifted, I was picking up glimpses of a few stellar pin pricks across the face of the core. Viewed with 199x additional stars were drifting in and out of view across its disk, but it remained largely unresolved, though bright and impressive. Another William Herschel discovery, he first observed this object in 1785.
Moving to the dolphin’s nose, mag 5.1 Gamma Delphini, I then moved eastward not quite 3.5° to pick up a quadrilateral of four stars (6th to 8th mag). The cluster was spotted immediately northeast of the northwestern star in this pattern. Easily spotted at 152x it was small and slightly dim, presenting a homogeneous little disk. With 199x it was more apparent, and though its core showed some subtle signs of brightness, it remained a smooth round orb. I did bump up to 283x and I then starting picking up a few intermittent stellar points across its small disk. Its core seemed stellar at this point. Overall it was a very weak visual object when compared to its constellation mate,
I really like this cluster! I have returned to it several times in recent years. I think it is simply a gorgeous cluster, set within a busy Milky Way field. So here I am, back again. Aiming the scope at Gamma Sagittae (mag 3.5), I quickly found this cutie-pie. At 152x it was very bright, set within a beautifully rich field. Countless stars were resolved across its very loose irregular disk. Studying it closely I had a strong sense of a triangular shaped diffuse core region. This was something that I don’t recall seeing previously. Going up to 199x it was outlandishly beautiful. The loose structure was exuding stars in all directions, with edges ill-defined as it dissolved into the rich field in which it is set. All the while that sense of a triangular diffuse core area still caught my eye. This is definitely one of my all-time favorite globulars. Discovery credit for this object is a bit confusing. It is likely that Philippe de Chéseaux observed it around 1745-46, but Johann Koehler also found it somewhere between 1772 and 1778. Then enter
I now found myself in the celestial eagle. Pointing the scope at mag 3.4 Delta Aquilae, I slipped southwest about 4° to find a curving figure of field stars. Sitting in this grouping I spotted my quarry. Easily spotted with 152x, it presented a slightly small and subtly dim round glow. No resolution of its disk was noted, as it remained a ghostly orb. Then at 199x some very subtle granularity was being detected, but little else. Going ahead to 283x a little more of its grainy texture was noticed, but there was no real resolution of this diffuse ball. This cluster was discovered by John Russell Hind in 1845
Palomar 11 (Aquila, globular cluster, mag=9.8, size=10.0’, SBr=14.5, class=11):
This object was last observed in 2013, so off I went in search of this challenging object. Winding my way southeasterly from Delta Aquilae, I finally located my field a little over 12° SSE of Delta. I picked up a small house shaped grouping of stars (7th to 9th mag), then shifted my attention to its northeast next to a mag 8.6 field star. At 152x I was picking up a very small and very weak rounded glow immediately southeast of the star. It was elusive and seemed to waft in and out of view as seeing shifted. Going to 199x it was more apparent but still quite low in surface brightness. I then tried at 283x but it remained nothing more than a round diffuse light dusting of light adjacent to the star. This object was discovered on the original Palomar plates in the 1950s. Some of those who worked on the project read like a who’s who of professional astronomers - George Abell, Fritz Zwicky, Edwin Hubble, Halton Arp and Walter Baade. Two of the 15 Palomar globulars were previously discovered visually, Pal 7 by Lewis Swift in 1889 and Pal 9 by William Herschel in 1784.
While I did not intend to do any galaxy hunting, I did decide to pay this one a visit as it too was observed nine years ago along with Pal 11. About 2.5° south of Pal 11, I found a scalene triangle of three stars (6th, 7th and 9th mag). The galaxy lay along one side of this figure and there I searched. Using 152x I picked up a small and round very ghostly glow with a very subtle brightness in its core. Because of the poor conditions most of the outer extent of this face-on barred spiral was just not being picked up. I also observed with 199x and 283x, and while more apparent, it was still weak visually. It remained very ghostly and diffuse. However, a very weak stellar core was now being picked up. Additionally at 283x I was also getting very sporadic flashes of a foreground star off-set from the stellar core near the edge of the haziness of the galactic disk. I think under better transparency this could be an interesting one, and I hope to check it out again. William Herschel was the first to observe this object, doing so in 1788.
Alessi 10 (Aquila, open cluster, mag=7.3, size=18.0’):
This cluster was my only new object for the evening. Since it was close to the area where both Pal 11 and
It was now after midnight, and I had endured the weak conditions, heavy dewing (dew heaters were at work), periodic bands of clouds, and finally a lot distant lightening flashes. So this beautiful globular would be my final object. Aiming the scope at mag 2.1 Enif (Epsilon Pegasi) and made the hop to the northwest to easily sweep up M15. At 152x it was very bright and very large. Round in shape, myriad stars were resolved across the disk, with a strongly bright compressed core serving as a beautiful backdrop to the countless stars. It reminded me of one of those large fireworks going off with all the sparkles bursting out from the center. This cluster is always a stunning visual treat and a very pleasing way to wrap up my evening.
And that was a wrap on the evening. While the conditions were nowhere near what I had hoped for, it was still a pleasing and rewarding outing. I got to revisit some old friends from nights of old, and revel in the distinctive beauty of globular clusters. It is easy to just assume they all will look alike because they do share commonalities. However, they are all still unique and present interesting contrasts at times. Thanks for coming along on this short journey, and I hope to see you back out there the next evening. The technician will not get over here until Friday morning, so that gives me one more night to peruse the night sky before heading home. Keep looking up friends.
). With the short time and poor conditions you still pulled out several nice globular clusters in your session. Thanks for your latest report Alan and I hope that you can get back to plan A again soon.
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Will try again tonight.