Hyperventilating to boost acuity
Hi fellas, I'm back in civilization after nearly 2 weeks at the farm. Great skies after a slog of rain, but oh my heaven how good that burger tastes at the local teenager hangout!
I looked over my logs, and there are very few NGC globulars I haven't resolved from the overhead menu this time of year. In Norma, 5946; Lupus 5927 & 5986; Sco 6541, 6496, 6453 adj to M7; Ara 6352; Cor Austr 6723. N6526 in Sco is unusual in that it resolves into ~20 shimmering specks without any sign of subliminal glow. The toughie of the less-reported GCs in the area is 6388 on Sco-Ara border. It's very bright & pops out against the field, but is a tight Class III with so much crowding effect nothing stands out. It laughs at 370x in my 200mm.
Skies may have something to do with the general resolvability, but it also may be that I look at anything for a half hour at a time, switching eyes frequently. When the object is really dim, I hyperventilate the way sharp-shooters do. Three or four rapid deep breaths followed by half-exhaling and holding it. I can't quantify the improvement, but I'd say offhand I can pull another half mag out of a field for the 10 or so seconds the effect lasts. The decline in acuity is unmistakable as the oxygenation wears off.
There's a long, interesting thread in CN re. the GC N6749 in Aquila. Said to be the toughest NGC globular around, I'm going to try it when I get back to the farm. Anyone else want to give it a look so we can compare notes? I've been researching it in the literature and the current theory is that 6749 is a remote halo GC plunging through the Galactic bulge and being stripped naked as it goes. It is now the loosest GC in the sky and may emerge from the present tidal ordeal a shell of its self on arrival. (The same thing happens when you go to the casino.) It's pretty much agreed that our Galaxy's outer halo comprises a lot of stripped globular stars. Very low metallicities and in many cases retrograde motion are the tip-offs. Keep your eyes on N6749 for a gigayear or so and we'll know for sure.
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