Observing Report 17/5/10 – 18/5/10

[barx1963 (Malcolm)]

Observing Report 17/5/10 – 18/5/10

All observations made using Dobsonion mounted 305mm Newtonian reflector at f/5. Eyepieces use are 32mm (47x) 24mm Panoptic (67x) 13mm Nagler T6 (115x) or 13mm Nagler with Barlow (230x)

Charts - Uranometria 2000 (2nd ed.) Data derived from Uranometria (2nd ed) Deep Sky Field Guide.

Observations 17/5. Seeing very good, transparency fair, however transparency improved over course of the evening

NGC 6293 Globular Cluster in Ophiuchus (Hartung 698)
RA 17 10 10.4 Dec -26 54 34 Total Vm 8.3 Brightest Star Vm 14.3 HB Vm 16.5 Diam’ 8.2 Concentration Class 4

From naked eye star Theta Ophiuchi, locate uneven pair of 39 Ophiuchi 1deg to Np then move 2deg South and slightly in p to grouping around 36 Ophiuchi . Move in p about 1.5deg and target is easily visible in wide field eyepiece at 62x. Small with very bright core. M19 lies 2deg to p.

NGC 6369 Planetary Nebula in Ophiuchus (Hartung 730)
RA 17 29 20.5 Dec -23 45 34 Diam” 38 Mag(P) 12.9 Mag(V) 11.2 Mag Central Star 19 Alt Name PK 2+5.1

From Theta Ophiuchi move slightly North of f to 2 stars 1deg apart both mag 4 and 4.5, target lies 40’ Np of f star. Very close to a mag 7 star. Small and fairly faint, just barely distinguished at 62x. At 115x clearly a planetary nebula but no structure visible. No central star.

NGC 6355 Globular Cluster in Ophiuchus (Hartung 724)
RA 17 23 58.6 Dec -26 21 13 Total Vm 8.6 Brightest Star Vm Unknown HB Vm 17.2 Diam’ 4.2 Concentration Class Unknown

From Theta Ophiuchi scan 2deg South to detect faint group of mag 7 and fainter stars in finder. 3 of them form a line running NS about 10’ long. Move f about 40’ to detect a very faint glow in 24mm ep at 62x which is significantly more prominent at 115x. Fairly small and not resolved.

NGC 6284 Globular Cluster in Ophiuchus (Hartung 695)
RA 17 04 28.8 Dec -24 45 53 Total Vm 8.9 Brightest Star Vm Unknown HB Vm 16.6 Diam’ 6.2 Concentration Class 9

From M19 find pair of mag 6.5 stars (28 + 31 Ophiuchi) lying about 40’ to Nf. Another pair of mag 7 stars 10’ apart lie about 1.5deg to North. Target lies 30’ to South of these. Small but with a very prominent core, fairly condensed. Lies with a very hazy background of Milky Way stars.

NGC 6356 Globular Cluster in Ophiuchus
RA 17 23 35.0 Dec -17 48 47 Total Vm 8.2 Brightest Star Vm 15.1 HB Vm 17.7 Diam’ 10.0 Concentration Class 2

From Theta Ophiuchi locate 40 (Xi) Ophiuchi 4deg to North. A 1.2deg wide triangle of mag 6.5 stars lies 2.5deg to North. M9 (NGC 6333) loies just on f side of this and is visible in finder. Target lies just outside of North side of this triangle. Fairly large and bright, outlying stars just resolveable.

NGC 6342 Globular Cluster in Ophiuchus (Hartung 719)
RA 17 21 10.2 Dec -19 35 14 Total Vm 9.5 Brightest Star Vm 15.0 HB Vm 16.9 Diam’4.4 Concentration Class 4

Lies just South and f of southern star of triangle mentioned above. Very small and faint but resolved at higher power. Lies on edge of dark nebula B259 which probably contributes to extinction.

NGC 6453 Globular Cluster in Scorpius (Hartung 750)
RA 17 50 51.8 Dec -34 35 55 Total Vm 10.2 Brightest Star Vm 14.3 HB Vm 17.5 Diam’ 7.6 Concentration Class 4

Lies on f side of naked eye cluster M7 (NGC 6475). There are 2 relatively bright (mag 5.5) stars lying on f side of cluster. Target forms an equilateral triangle with these 2 stars. Very faint but size suggests cluster should be brighter. Closeness to galactic core probably impacts in terms of extinction.

NGC 6441 Globular Cluster in Scorpius (Hartung 748)
RA 17 50 12.9 Dec -37 03 04 Total Vm 7.2 Brightest Star Vm 15.4 HB Vm 17.1 Diam’ 9.6 Concentration Class 3

From M7 move S about 2deg to mag 3 G Scorpio which is a very bright lemon yellow star. Target lies just to f side. Although it is large it is faint and as with NGC 6453 extinction is obvious. Presence of G Scorpio makes it appear fainter. Field also contains a very faint almost stellar Planetary Nebula about mag 14 that is not dimmed by OIII filter. This is P353.5-4.9.

Observations 18/5. Seeing very good, transparency good, however transparency improved over course of the evening until midnight when it appears excellent.

NGC 6522 Globular Cluster in Sagittarius (Hartung 766) and NGC 6528 Globular Cluster in Sagittarius (Hartung 769)
NGC 6522 RA 18 03 35.1 Dec -30 02 02 Total Vm 9.9 Brightest Star Vm 14.1 HB Vm 16.9 Diam’ 9.4 Concentration Class 6
NGC 6528 RA 18 04 49.6 Dec -30 03 21 Total Vm 9.6 Brightest Star Vm 15.5 HB Vm 17.1 Diam’ 5.0 Concentration Class 5

Locate Gamma Sagittarii (Alnasi) by naked eye. Target lies 0.5deg Np from this star. A fainter globular cluster lies within Field of View which is NGC 6528. NGC 6528 is noticeably smaller and fainter but makes an interesting view at 115x.
NGC 6522 shows mottling at 115x and a very faint star is on f edge. Reasonably dense core. NGC 6528 shows no structure.

NGC 6569 Globular Cluster in Sagittarius (Hartung 787)
RA 18 13 38.9 Dec -31 49 35 Total Vm 8.4 Brightest Star Vm Unknown HB Vm 17.1 Diam’ 6.4 Concentration Class 8

From Gamma Sagittarii (Alnasi) a mag 5.5 star lies 1deg to Sf then proceed 1.5deg to Sf to a mag 6.5 star. Target lies 5’ to North. Unresolved, fairly large but faint. Lies within Dark Nebula B305 which is contributing to extinction.

NGC 6558 Globular Cluster in Sagittarius (Hartung 782)
RA 18 10 17.6 Dec -31 45 47 Total Vm 8.6 Brightest Star Vm Unknown HB Vm 16.7 Diam’ 5.2 Concentration Class Unknown

Lies 1deg to p side of NGC 6569. There is a mag 8 star within field to North, another lies just outside field to South. Very small and faint, not resolved, minimal condensation.

NGC 6563 Planetary Nebula in Sagittarius (Hartung 785)
RA 18 12 02.5 Dec -33 52 06 Diam” 48 Mag(P) 13.8 Mag(V)11 Mag Central Star 17.3 Alt Name PK 358-7.1

From NGC 6558 proceed South about 2deg to uneven pair of mag 6 and 7 just visible in finder. A mag 7 star lies 20’ to Sf. Planetary Nebula is just North of this by about 10’. Rounded and clear in OIII filter. North side appears to have sharper boundary. No central star detected.

NGC 6624 Globular Cluster in Sagittarius (Hartung 798)
RA 18 23 40.5 Dec -30 21 40 Total Vm 7.6 Brightest Star Vm 14.0 HB Vm 16.1 Diam’ 8.8 Concentration Class 6

Locate Kaus Media (Delta Sagittarii). A mag 5.5 star (18 Sagittarii) lies 1.4deg to Sf. Target lies halfway between these stars. Condensed core, quite bright. Averted vision reveals and extended ‘halo’ . At low power core is nearly stellar.

NGC 6652 Globular Cluster in Sagittarius (Hartung 814)
RA 18 35 45.7 Dec -32 59 25 Total Vm 8.5 Brightest Star Vm 13.3 HB Vm 15.9 Diam’ 6 Concentration Class 6

From Kaus Australis (Epsilon Sagittarii) move 2 deg to Nf to a wide pair of mag 6.5 stars running pf about 1deg apart. Target lies 30’ to f of f star. Fairly faint but a very pretty globular. A mag 6.5 star lies 5’ to North. Some mottling, condensation is moderate. Not quite round. Appears to havean elliptical halo that gives it an almost ‘galactic look.

Malcolm

[kustard (Simon)]

Nice report and some nice objects over those two nights, might have to do that tour myself

[barx1963 (Malcolm)]

Thanks. My focus was on GC in the Scorpius, Sag and Oph area, theres heaps of 'em, all different. It's challenging trying to resolve stars in them, and for the really faint ones, sometimes a challenge just to see.

[pgc hunter]

Lots of decent globs in that area that's for sure. Ara and Corona Australis are excellent aswell. A few surprises lurk there, alot are quite spectacular yet are never mentioned, like NGC 6541 for example. M55 is another ripper that seems to be forgotten.

Also the sky's biggest concentrations of Planetaries to be found here aswell

[barx1963 (Malcolm)]

Yes Sab, lots of planetaries. I got a couple and a couple more possibles, but most of them are really small, and hard to get, and I only had fair to good transparency until the last half hour on the 18th when it became excellent. LP that I always battle doesn't help with the PN's.

[barx1963 (Malcolm)]

Report now updated with data.

[Paddy (Patrick)]

Couple of good nights' play amongst the globs there, Malcolm. So much to look at, so little time!

[ngcles]

Hi Malcolm,

Originally Posted by barx1963

Thanks. My focus was on GC in the Scorpius, Sag and Oph area, theres heaps of 'em, all different. It's challenging trying to resolve stars in them, and for the really faint ones, sometimes a challenge just to see.

Great report mate much enjoyed -- I love G.Cs and have spent a lot of time over the years hunting down as many of the little buggers as I could -- but I think I've reached the limit for my aperture now. Unless I move to 22" (and I don't think I will) theree's no more to find for me at the moment.

If you're after a serious challenge for your 12" in Scorpius, why not try to track down NGC 6380 (2nd worst of the NGC G.C's) and close-by Ton 2 in the tail? And then, while your in the area, have a crack at the brightest and easist of the Terzan list -- Terzan 3 above the back of Scorpius.

All good fun!

Thanks for taking the time to post and share your observations!


Best,

Les D

[barx1963 (Malcolm)]

Thanks Les and Paddy
Les I did a very quick look for Terzan 3, didn't get it but it was late and getting very cold and was really focusiing on packing up. Next time maybe.
I must prepare a little list of all the NGC Globs around the Sag and Scorpius area and get a bit more systematic to take advantage of any decent nights over the next few months while Glob Central is easy to search.