Observation notes 2/9/10

[Paddy (Patrick)]

Behold! A (sort of) clear night! Here are my notes for those who might be interested.


Telescope 400mm f4.9 tri-dob reflector
Eyepieces 28mm UWAN, 17,13,9 mm Naglers, Paracorr
Guiding: Night Sky Observer’s Guide (NSOG)

Seeing ordinary 3/5
Transparency poor 5/7 at start of session, good 6/7 at end of session

Driven by extreme hunger for astronomical observation, I wheel my scope out under hazy skies, Venus and Jupiter surrounded by thick discs of blur obvious to the naked eye, the milky way discernible with little detail, but it’s go to be better than nothing…

2030

NGC 6231 OC in Scorpius
Dia. 14’ V.Mag. 2.6 Trumpler Type I3p

135X (Unfortunately I have a problem with recorder for the first part of this observation, so I miss some details) A tight pack of bright white and blue-white stars occupying about a third of FOV. Most of the brightest stars form an arrow-shaped asterism surrounded by a spattering of fainter stars. As I observe, the haze dissipates a little and the contrast increases and th cluster appears even more magnificent. At the tail of the arrow (east) is a close pair of similar magnitude. A line of three bright stars projects form the south of base of the arrowhead. Further to the south is a spray of stars to the west curving to the east.

NGC 6242/Collinder 317 OC in Scorpius
Dia. 9’ V.Mag 6.4 Trumpler type I3m

80X About ½ way between Zeta and Mu Scorpii, 6242 sits on the other side of the Tr24/IC 4628/Collinder316 complex to NGC 6231. Another very closely packed OC, the lucida seems yellow-white compared to the rest of the cluster’s members. Not nearly as bright as 6231. There seems to be a dark gap in the middle and the cluster has 2 rabbit ear like projections heading south from the middle of the cluster. The lucida is on the tip of the northern ear, which has a dark lane down the centre. There is a spattering of fainter stars around this northern arm.

NGC 6268/Collinder 323 OC in Scorpius
Dia 6’ Mag 9.5(p) Tr Type II2p

135X Fainter again than 6242, much more delicate OC, no really bright stars but more variation in colour with more yellowish stars than 6231 or 6242. It also appears somewhat looser, but not spread over a wide area of sky. The cluster appear to consist of 2 E-W zigzagging lines, one with fewer but larger zigzags to the south and the northern one having smaller and more. A relatively bright pair of yellowish stars sits at a point in the northern line.

Barnard 48 Dark nebula in Scorpius
40’x40’?

80X Lies to the east of Tr 24, dark lane through the stars. I find it hard to pick the edges of this and to me it appears a nearly 120’ x 60’ sausage. The NSOG lists it as 40’x 40’ then describes it as 40”x15”, so I am none the wiser. In the area of darkness that I observe, there are some patches faintly discernible stars, so I may be including bits that don’t belong.

Trumpler 24 OC + IC 4628 (Gum56) Emission nebula in Scorpius
Dia 60’/90x60 Mag 8.6(p) Tr type IV 2pn

90X An eyepiece full of bright stars with haze of IC 4628 occupying the northern part. A few asterism stand out neat IC 4628. Firstly a delightful little wavy line of bluish stars at the southern edge of the emission nebula. Further to the south is a tight bunch of bright white and blue-white stars, one more yellow. Continuing a line from the wavy asterism through the tight bunch, there is a small asterism which looks like a small faint version of the constellation Delphinus. Most of the interesting asterisms in the cluster consist of fainter stars. Overall the cluster is a broad swathe of stars with significant variation in brightness but not in colour. I cannot determine the boundary between Tr 24 and Collinder 316.

NGC 6281/Collinder 324 OC in Scorpius
Dia 8’ Vmag5.4 Tr type II2p

135X To the east of Mu Scorpii this is an elegant cluster of about 30 obvious stars. The northern edge is formed by a gentle concave E-W curve of about 8 stars. To the south, two intersecting arcs of stars, convex-south, complete the cluster, creating the impression of a somewhat distorted Beta sign. A few stars lie outside this shape. The cluster stands out well against the background stars. Most of the stars are white and blue white with only a few yellower ones - there seems little variation in brightness or colour.

NGC 6362 GC in Ara
Dia 15’ VMag 8.1 Class X

135X Nearly in Pavo, this is a very diffuse GC, quite large with many faint resolvable stars, a little concentration towards the centre, no core, and a very gentle falling off of brightness towards the edge. Quite a few wide areas of haze drawn out from the cluster, a very wide one to the east, another to the south, west and a faint one to the north. No notable asterisms ore darker areas in the GC.

IC 4653 GX in Ara
Dia 1.1’ Vmag 12.5 SB

175X This small faint oval of haze is quite near Delta Arae and is in a patch of sky surprisingly clear of foreground stars for this neck of the woods and so is quite easy to pick out. Elongated roughly E-W. With averted vision, it looks to have a slim line of brighter haze within the broader oval halo.

IC 4651 OC in Ara
Dia 10’ Vmag 6.9 Tr type II2r

135X The members of this OC also appear fairly similar in colour and magnitude, mostly white stars and a few slightly yellow ones. Quite a tight bunch of stars in the centre. To me the cluster seems bigger than the quoted size in NSOG, looking about 15’x 10’ with quite a swirl of stars, bent up on itself into quite a complex shape. A big loop of stars on the eastern side oriented N-S is reminiscent of the top of a treble clef. To the west is a horsehead shape. Quite interesting.

NGC 6352 GC in Ara
Dia 9.0’ Vmag 7.8 Class XI

175X A very broad and diffuse GC with many faint resolvable stars, slightly brighter in the centre but no core and very even, gentle fading to the edge. The edge itself is very irregular and it is hard to pick where the GC ends and the background stars begin. Some dark lanes are apparent, looking like thin cracks in the GC. The northern edge looks flat compared to the other borders.

NGC 6326/PK338-8.1 PN in Ara
Dia 19” Mag 12.2(p) Type 3b

250X A small bluish disc with firm edge, close to 2 stars. I have a strong impression of fainter nebulosity extending beyond the brighter disc to these 2 stars. No central star or sign of internal structure. OIII filter confirms the sense of fainter nebulosity extending from the disc towards the 2 stars. Again, no sign of internal structure.

NGC 6397 GC in Ara
Dia 31’ Vmag 5.3 Class IX

135X A beautiful GC with bright central core, many resolvable stars, but there is a gap in these allowing clear view of the unresolved core. A ring of bright resolvable stars surround this.

Transparency has improved consistently and is now 7/7. I curse the need to get up early for a train to Melbourne in the morning as this would be a superb late night. Quick visits to NGC 104/47 Tuc, Jupiter and MGC 6752 to cap the evening off.

[kustard (Simon)]

*Envious*

Excellent observations as always Patrick.

[orestis]

Excellent observations,Patrick

Completly clouded out down here and have not observed for a long time now.

Thanks for posting
Orestis

[barx1963 (Malcolm)]

Well done Paddy. nice to see someone getting out. I managed to get out for a couple of Hours, but was so out of practice, and conditions were only average so decided to just look at the big stuff!
really enjoyed your report.

Malcolm

[pgc hunter]

Great salvage job there mate! I tried to go out on the same night, but all that stupid low-level cloud moved in and killed any chance. The high level haze was problematic aswell, but looked doable for brighter objects if it wasnt for that southerly mairtime crap.

How did Jupiter look?

[Paddy (Patrick)]

Thanks, all. Sab, the seeing for Jupiter was fairly poor as it had only just risen above some trees on the eastern edge of my viewing area. So I could only get to 135X and it was still pretty fuzzy. I think there was still a fair bit of thin high altitude haze in that part of the sky as well. I could however make out the NEB, hints of the temperate bands and even a bit of a suggestion of something where the SEB normally is. But it was pretty ordinary.

Malcolm, I'd had a night like yours during the week, looking at the things I can find easily and quickly as I was dodging clouds the whole time. I'd end up with a glance at anything at best and it was very hard navigating when only a few stars are visible. BUT THESE ARE DESPERATE TIMES!!!

Hope you all get to look at some stuff before moon intrusion.

[barx1963 (Malcolm)]

Looking a bit more promising Monday and Tuesday we hope.

[pgc hunter]

Originally Posted by barx1963

Looking a bit more promising Monday and Tuesday we hope.

Tuesday night is the biggest hope, what being a work night and all. I'm hoilding out for Wed as I've got thursday off... but I have a feeling it'll pull a Melbourne and cloud over at right on sunset. Once again, all the good ops are on the wrong end of the week