78 Globs over Shingletown

by Bob Jardine

A few months ago, I was thinking about a new project for SSP. I'm nearing the end of my Herschel-2 project, and with less than 50 objects to go on that list, not all available this time of year, I knew it wouldn't keep me busy. So, what to do?

Globs! A very large fraction of all GCs are available this time of year -- in Oph, Sco, and Sgr. And different from the monotony of the Herschel-2 tiny little galaxy project. So I decided to try to view them all! Well, almost...

I knew that there were some Palomar and Terzan and other obscure globs that would be out of reach for me, but it was realistic to plan to observe 100% of the NGC globs that weren't too far South or out of season. Surprisingly, there are only 3 IC globs, and one of them is way too far South. So the two Northern ones were on my list as well. Finally, I kept hearing about Djorgorvski 2 over the last few years, so that went on the list too.

I'll not bore you with the gory details. I've included my observing notes for a few of the more interesting and/or challenging ones below. Here's the summary:

70 NGCs

1 IC

2 Terzans

4 Palomars (I actually observed 6, but one is also an NGC and one an IC, both counted above)

1 Djorgorvski

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78 Total

SSP was big fun, as always. Thanks everyone!

Cheers, Bob J.

(selected details follow)

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Observations were with my 17.5" LTD ("Albert-o-scope"), using 7mm, 9mm, and 11mm Naglers. For consistent comparison, I viewed them all with the 9mm, and I used the 7mm and 11mm occasionally as necessary.

Conditions: clear every night; my SQM hoovered around 21.6 every night, but I did record a 21.74 on Wednesday -- that's the best mine has ever recorded (although it hasn't been to Oz yet). I was getting consistently 23 stars (mag 6.2) in the Bootes-CrB triangle, although I got 26 (6.3-6.4) once (not surprisingly, that was when the SQM read 21.7+). Seeing was uniformly poor the first night, then poor-fair (depending on altitude) the rest of the week, but actually got to fair-good on Sunday night.

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NGC 4147, Com. Not sure why this is on someone's "challenge" list. It was pretty easy to hop to and not too hard to see. Small, but pretty bright. Grainy, but not resolved.

NGC 5053, Com. Another "challenge" list item. Pretty easy location near M53. Pretty large, but very dim, low surface brightness. Hard to tell the shape, but a hint of triangular shape. About one half dozen stars resolved.

NGC 5466, Boo. Easy hop East of M3. Pretty large (almost as large as M3). Quite dim, low surface brightness. About 10-12 stars resolved. Not much brighter center.

NGC 5634, Vir. A glob in Virgo? Pretty small, quite bright. In a little triangle of stars. No resolution, just grainy. I also saw another little dim glow in the field, but I couldn't ID it.

NGC 6401, Oph. Interesting one -- pretty small, pretty dim, low surface brightness; but a bright star at center -- probably foreground; otherwise, no resolution.

NGC 6453, Sco. Very small, pretty dim, but easily noticed. Situated among stars of M7 (obviously beyond M7). Not resolved -- just a grainy glow. Maybe a little bit brighter center.

NGC 6540, Sgr. Pretty small, medium bright. Elongated E/W, not round! Grainy glow, no resolution. In a rich foreground star field. Not much brighter center. Located just East of 6520 & the Inkspot.

NGC 6553, Sgr. Medium size, pretty bright. Rectangular! A foreground star (I suppose) on SE corner. Hint of 2 or 3 resolved stars, otherwise grainy. Uniformly bright, not brighter center.

NGC 6749, Aql. A very difficult object; why isn't this one on the "challenge" list? It is more difficult than Djorgorvski 2, NGC 4147, and NGC 5053. Pretty large, dim, very low surface brightness. Unresolved, not even grainy glow. Tried for this one on three straight nights, finally succeeded on the third night. The glob bisects a line between a mag 9 star and a wide double of two mag 8-9 stars.

IC 1257, Oph -- my only DNF. Tried on two successive nights, with no luck. Maybe just getting tired when I tried it. "I'll be back."

Palomar 4, UMa. A glob in UMa? What's up with that? Required attempts on two separate nights. Very small, very dim (edge of detection directly). Like a dim star, but suspiciously fuzzy.

Palomar 6, Oph. Strongly suspected, but only with AV and observing hood, careful breathing -- all the tricks. Fairly large, very dim, very low surface brightness. Not brighter center.

Palomar 7, Serpens (aka IC 1276). Small, pretty dim, low surface brightness. A star on WNW edge, otherwise not resolved.

Palomar 8, Sgr. Really surprisingly easy. Easier than Pal 4 and Pal 6 and no more difficult than several of the NGCs. Pretty small, but not tiny. Dim, low surface brightness. Not brighter center -- uniformly dim.

Palomar 9, aka NGC 6717. Easy to find, but hard to observe, because it is in the glare of a very bright star. Very small, but quite bright. Looks like two clumps of brightness, like two lobes, but no resolution.

Palomar 11, Aql. Suspected strongly only by using the observing hood and all the tricks. Medium size, very dim, very low surface brightness. Not grainy, much less resolved.

Terzan 3, Sco. Quite small, very dim, very low surface brightness. In fact, it is only barely there direct vision, really needs AV. Uniformly dim, not brighter center. No resolution.

Terzan 7, Sgr. Pretty easy location due to a finder-scope pair of stars in FOV. Pretty small, but not tiny. Very dim, very low surface brightness. Just an AV glow, not even grainy, much less resolved. Uniformly dim, not brighter center.

Djorgorvski 2, Sco. Not as difficult as I expected. Pretty easy hop from 6520/Ink Spot. Medium size, dim, low surface brightness, but definitive glow inside a trapezoid of stars, one much brighter than the other three.