OR: gobbling globulars / part 1 the exotic

My chance for new moon observing came last night, 1 July. Transparency was forecast to be good and seeing was above average, so I drove down to the central coast. I planned to arrive by 8:30pm, but due to some traffic arrived around 9:00pm. No matter, I had an easy set-up as I only brought a C8, an 80ED, and binoculars. It was windy in the dusk as I set-up and for the first hour after darkness, with the air from higher elevations rushing down slope. Seeing toward the horizon was poor, but not bad 20-degrees up. It remained warm all night, though I eventually put on a fleece and hat late at night. SQML 21.4, respectable.

I determined to observe globular clusters almost exclusively this night. Using Alvan Huey's observing guide, I tore through the list. From 10pm to 2am, when I finally stopped, I observed 77 objects! Good setting circles and using the night vision make it easy.

Haute Province 1 (Ophiuchus): 17 31 05.2 -29 58 54, Vmag 12.5, SB 12.9, size 1.2’:
I remember observing this first with my 20-inch at Willow Springs years ago. At the time I wrote: "According to one "Dennis" who posted his image of the object in IceInSpace: "Discovered by Dufay, Berthier and Morignat in 1954. Independently rediscovered by van den Bergh and Hagen in 1975. Globular Cluster HP 1 was discovered by Dufay et.al. (1954), and sometimes referred to as "HP" for the Haute-Provence Observatory where the discovery occurred (e.g., Sawyer Hogg 1959). This designation was mutated to HP 1 as more globular clusters were discovered at that observatory in the 1960s by Terzan. Until recently, it was thought that HP 1 is situated close to the Galactic Center, but recent estimates have put it as far as about 20,000 light years beyond, to a total distance of 46,000 light years from us." In my scope it appeared as a very faint, small irregular splotch at the western rim of a shallow upturned arc of 5 stars. The greyishness began to turn grainy with AV, hinting of some resolved stars."
With the C8+NV it was small, with a bright stellar core and a round grainy concentration of stars, easy direct vision. It was capped by a distinctive arc of three similar magnitude stars and lay in an extremely dense star field.

Palomar 7 (IC 1276) (Ophiuchus): 18 10 44.2 -07 12 27, Vmag 10.3, SB 14.8, size 8’
With the C8+NV, it was rather bright and large, loose, open cluster like, with mostly similar magnitude stars.  Discovered by American astronomer Lewis Swift on 10 April 1889 using the 16-inch Refractor at Warner Observatory, Rochester.  Distance from Sun 17,600 light years, from Galactic Center: 12,100 ly.

[PWM78] 2 (aka Pfleiderer 2) (Ophiuchus) 17 58 39.4 -05 04 21, Vmag -, SB -, size 2’.
This is a globular cluster candidate, identified as such in a 2009 paper using the 3.58 m Galileo telescope (TNG) at La Palma. It was very difficult.  After navigating my eye to the correct location using Huey's guide, I didn't see anything. Then I thought to play with the gain knob, turning it all the way up then dialing it down while I looked through the NV device. When I did this, I noticed a very small, out of ground grey non-stellar glow which remained the same size when turning the gain from high to medium -- I lost the view when the gain was less than medium. I'd call this a tentative observation but there was definitely something there.

Tonantzinlia 2 (Scorpius): 17 36 10.5 -38 33 12, Vmag 12.2, size 2.2'
This was rather easy. I picked it out in the field immediately as a small weak glow within a triangle of stars, one bright and the other two fainter (matching the guide).  Discovered by Paris Pismis from Tonantzintla Observatory in Mexico in 1959.

ESO 280-SC06 (Ara): 18 09 12.7 -46 25 26, Vmag 12.0, size 1.4’
A "definite maybe" observation. This took a while to observe (and find the correct location within the multitude of stars in the field).   I observed an extremely small non-stellar glow -- and by this I mean it looked softer than stars of similar magnitude in the view, which had a point-source hardness about them -- at the correct location. In this DSS photo I mark the GC with red hash marks, which was the apex of a triangle of two field stars marked in blue -- which is what I drew on my field sketch. The actual scale in the eyepiece was much, much smaller.  Wikipedia puts it at 69,800 light years, a sparsely populated with a compact core.

AL 3 (Sagittarius): 18 14 06.6 -28 38 06, Vmag 14.0, size 1.3’
I again used the gain knob trick, after first locating the distinctive string of three stars. Very, very small, and faint, but there was the round grey glow that did not look like a star at that location at high gain. NV view much smaller scale.  The discovery paper abstract says "AL 3 (BH 261), previously classified as a faint open cluster candidate, is shown to be a new globular cluster in the Milky Way, by means of B, V, and I color-magnitude diagrams. The main feature of AL 3 is a prominent blue extended horizontal branch. Its color-magnitude diagrams match those of the intermediate-metallicity cluster M5. The cluster is projected in a rich bulge field, also contaminated by the disk main sequence. The globular cluster is located in the Galactic bulge at a distance from the Sun dsolar=6.0+/-0.5 kpc (~20,000 light years). The reddening is E(B-V)=0.36+/-0.03, and the metallicity is estimated to be [Fe/H]~-1.3+/-0.25. AL 3 is probably one of the least massive globular clusters of the Galaxy."

ESO 456-SC38 (Sagittarius): 18 01 49.1 -27 49 33, Vmag 9.9, SB 14.9, size 9.9’ =Djorgovski 2
This one was easier than the last, it was larger and "brighter" haha. Flat grey irregularly round glow, in a square asterism of four stars. From a 2019 paper: "The object ESO456-SC38 (Djorgovski 2) is one of the globular clusters that is closest to the Galactic center. It is on the blue horizontal branch and has a moderate metallicity of [Fe/H]∼-1.0. It is thus similar to the very old inner bulge globular clusters NGC 6522, NGC 6558, and HP 1, and therefore appears to be part of the primeval formation stages of the Milky Way."  They estimate it at 28,500 light years from us.