Took the 12" dob out for the first time in months last night with the intention of observing Saturn. But being well placed only at 4am, I decided to kill some time hunting a few PNs.
Seeing was pretty much garbage, Transparency wasn't spectacular either. However, seeing seemed to improve slightly during dawn, giving some decent views of Saturn.
Ghost of Jupiter
One of the best PNs out there! At 404x (probably a bit silly given the seeing) - central star was obvious and the eye shape easy to make out. The ends of the 'eye' seemed to be brighter than the rest of the structure, with a fainter nearly circular haze surrounding it. To me , this PN displays a vivid blue colour, one of the most richly coloured objects I've seen.
NGC 5189 - Spiral Planetary
Using 217x with an OIII filter, this unique PN is reminiscent of a barred spiral galaxy. A bright central "bar" was visible, with a 'hook' at its east end curling back toward the south. A fainter detached knot was also visible immediately to the SE of the main complex. At the Neb's west end, 2 faint filaments extent and curve toward the northwest. The whole complex is bathed in a fainter nebulosity, which was most obvious along the southern edge of the bar.
NGC 5315
This is a very tiny PN in Circinus. At 216x without filter, it was almost stellar. WIth the OIII filter, it appeared as a tiny, circular, bluish orb. Has very high surface brightness. Unfortunately due to seeing, I couldn't let loose with the magnification on this one.
IC 4191
PN in Musca. So tiny is this object, that it was virtually stellar even above 200x. Even at 283x, I had to blink with the OIII to sift this microscopic bugger from the rich starfield! Finding the right field is easy enough, with Eta Muscae less than a degree away, and 6.5th mag star L5393 about 10' to the south. The challenge is actually identifying it in the profuse starfield! Without filter, it is practically stellar, even at 283x. With the OIII at 283x, it stood out well, with a tiny circular disk. Has a high surface brightness although due to the seeing, high mags were out of the question.
SATURN
Seeing was pretty ordinary, but got my first proper views of Saturn this season. Seeing seemed to improve as morning twilight was underway , giving brief, satisfying views at 176x and 217x. Two broad pale cloudbands were visible either side of the rings while the rings themselves cast a nice crisp shadow on the globe. As sunrise drew nearer, I managed to get some decent views even at 283x. Was interesting seeing the rings in the edge on aspect, giving it the appearance of a cherry or grape skewered with a toothpic.
^^ Yep! Infact, I didn't even sleep at all. I took the scope out at 10pm, watched some TV while it cooled and began just after moonset. I was curious to get my first look at Saturn for this season, so I stayed up all night without a wink of sleep!
Good to read your descriptions of these interesting PNe -- thanks for taking the time to post so we can all read 'em.
Yep, IC 4191 is a rather nasty proposition from the point of view of its stellar-nature. Blinking, as you wrote is really the only option. Other than the exercise of finding/identifying the little blighter, there isn't that much to the view.
Very interested in your description of NGC 5189 -- which is really quite similar to my impressions back in 1998 with 25cm:
x181 17' TF. Mag 9.9 Size 100". A thoroughly amazing object, certainly the most interesting PNe in the southern sky. Very difficult object to describe adequately because the structure is so complex. Without the UHC filter it appears within a diamond shaped asterim of *s mags 10-12 about 5' x 2.5' in PA 20. With the UHC filter it is involved with the W most of these *s. Generally irregular in structure, kind of like a barred spiral eg which has a very strong bar and weak stubby arms and an extended halo all round. The bar is in PA 30, about 1.5-2' long, it is slightly curved, concave to the SE, and that flank is slightly generally a little brighter than it's counterpart and a little better defined. This bar is irregular in brightness and mottled. The brightest and broadest area is about the SSW end. Generally narrower in the NE and dimer. This bar seems to eminate from a point just E of the W most member of the diamond of *s I have described, and leads toward the N most member. At the NE end the bar has a bright "nob" at the end and then curls off in the direction of SE -PA 140 and terminates. At the SSW end there is a little extension that is less bright than the other end and curls away to head off generally W. A very large roughly round, slightly elong in PA 30 halo encircles the object with much lower S.B haze out to a diameter of perhaps 2-2.5'. The central areas are decidedly bluish without the filter and no central * is visible.
Have you taken a look at Musca's "forgotten" PNe NGC 4071 ??
And yep, I agree The Ghost of Jupiter (NGC 3242) is one of the most intensely coloured PNe in the sky.
I have attached a suitable finder chart (below) that might be helpful to you.
Also is some text that might be useful to you...
NGC 4071 / He2-75 / Sa2-82 / Wray 16-104/ PK298-4.1 / PNG 298-4.8. 0 (12043-6719) (U 450) is one of my favourite southern planetaries. It was discovered by John Herschel in 1838, some 1.9 deg NWW from 4th mag red variable Epsilon Muscae. Originally, he thought the object was a bright nebula, and had no inkling that it was a PNe. It was Karl Henize in his Southern Ha survey in 1961 who became first to discovered its real nature. Although few amateurs, until recently knew of NGC 4071's existence, mainly as it was classed as a nebula. This wonderful 12.9p mag elliptical planetary nebula is surprisingly brighter than expected, but unlike most PNe’s, its surface brightness is quite low, and this may account for some of the difficulty in seeing it using high magnification. This is similar to the problems with small apertures seeing the Helix Nebula in the constellation of Aquarius. Those who are fortunate to own an H$ filter, it is likely that it will be of some use with NGC 4071. As the PNe is classed as a low-excitation object, considerably gains in contrast certainly will enhance the faint detail inside the nebulosity.
Another fantastic image once posted here on IIS (posted on the 03rd September 2007, but now seemingly deleted). This was produced by Steve Quirk, and is one of the finest images I've ever seen of this particular object. This is now firmly placed in my own list of Top 10 images of southern objects. http://my.hwy.com.au/~sjquirk/images/gstar/ngc4071.html
(However, you might want to look at it yourself for before looking at Steve Quick's really impressive image.)
"Hi Les, what catalogue is that object in? Google didnt find it for me.
Could you let us know RA and DEC please?"
Well, if you look just a fraction higher than the description I provided I wrote:
"Very interested in your description of NGC 5189 -- which is really quite similar to my impressions back in 1998 with 25cm:
x181 17' TF. Mag 9.9 Size 100". A thoroughly amazing object, certainly the most interesting PNe in the southern sky. Very difficult object to describe adequately because ... " (Emphasis added)
Good to read your descriptions of these interesting PNe -- thanks for taking the time to post so we can all read 'em.
Yep, IC 4191 is a rather nasty proposition from the point of view of its stellar-nature. Blinking, as you wrote is really the only option. Other than the exercise of finding/identifying the little blighter, there isn't that much to the view.
Very interested in your description of NGC 5189 -- which is really quite similar to my impressions back in 1998 with 25cm:
x181 17' TF. Mag 9.9 Size 100". A thoroughly amazing object, certainly the most interesting PNe in the southern sky. Very difficult object to describe adequately because the structure is so complex. Without the UHC filter it appears within a diamond shaped asterim of *s mags 10-12 about 5' x 2.5' in PA 20. With the UHC filter it is involved with the W most of these *s. Generally irregular in structure, kind of like a barred spiral eg which has a very strong bar and weak stubby arms and an extended halo all round. The bar is in PA 30, about 1.5-2' long, it is slightly curved, concave to the SE, and that flank is slightly generally a little brighter than it's counterpart and a little better defined. This bar is irregular in brightness and mottled. The brightest and broadest area is about the SSW end. Generally narrower in the NE and dimer. This bar seems to eminate from a point just E of the W most member of the diamond of *s I have described, and leads toward the N most member. At the NE end the bar has a bright "nob" at the end and then curls off in the direction of SE -PA 140 and terminates. At the SSW end there is a little extension that is less bright than the other end and curls away to head off generally W. A very large roughly round, slightly elong in PA 30 halo encircles the object with much lower S.B haze out to a diameter of perhaps 2-2.5'. The central areas are decidedly bluish without the filter and no central * is visible.
Have you taken a look at Musca's "forgotten" PNe NGC 4071 ??
And yep, I agree The Ghost of Jupiter (NGC 3242) is one of the most intensely coloured PNe in the sky.
Enjoyed your report !!
Best,
Les D
Hi Les,
Thanks for you description of NGC 5189! NGC 5189 is certainly the most intruiging PN in the sky! No other PN anywhere in the sky comes close to its visual structure and detail that shows in the eyepiece. It would be a spectacular sight from dark skies. The transparency during the night was pretty ordinary and I was extremely tired so overall I didn't see as much as I probably would've.
I've had a shot at NGC 4071, very faint, infact barely visible without a filter, still feeble with the OIII in place at 217x. I has the impression of a circular or nearly circular ring, uneven in thickness and brightness. I'll have to investigate this one further on a night of better seeing/transparency and when I'm not half dead Also, external glare interfered with the obs, I'll have to throw a dark hood over my head and fashion a dewshield for the front of the 12" dob
IC 4191 is ridiculous! Anyone know the diameter for this one? (if it HAS one LOL!) There are alot of tiny planetaries in Carina aswell which I've observed during previous sessions that are nearly carbon copies, with tiny circular disks and bluish or aqua hues.
The Ghost of Jupiter is certainly fantastic, no where else in the sky have I seen such intense colour, (except the homunuculus maybe) and it's structure is fascinating aswell. Even my non-astronomer mum and grandma were very impressed!
These are the comments I have on the diameter of this object, however, to my eyes was about 3 to 5 arcsec, and this varies slightly with an O-III or not.
"In regards IC 4191, Karl Henize [in 1962] classed the PNe’s structure, by placing it second in nine-categories of PNe types- Ellipses gradually brighter in centre in order of core brightness. Henize also found the core’s diameter as 6 arcsec, about the size as seen in most amateur ’scopes. Observations from Mt. Stromlo found the outer halo dispersed its light to about 10 arcsec. Henize thought he had seen some elongation, and using the twenty minute photographic exposures, made an estimate PA of 50 degrees. He also commented that he thought the nebula appeared “peculiar triangular shaped.” [which I've never seen, which I assume might be some problem with the optics, perhaps.] This is particularly odd PNe description, but his impression is seen clearly in the image produced in the original paper. In the professional telescopes appears a very faint outer envelope can be seen to extend by some 18x11 arcsec. However, this is invisible in all amateur telescopes. Here IC 4191 remains about 5 arcsec across. Morano (1990) measured the H-alpha diameter as 11 arcsec., finding strong emissions in O-III and H-alpha. This is also especially prevalent within the inner parts of the nebulosity."
Smirnoff, your observation of NGC 4071 is broadly consistent with my one and only recorded observation of it back in 1999 with 25cm from suburban Engadine with a ZLM of about mag +5.1:
x181 17' TF. Mag 13.0 Size 80". This is a very LSB and fairly faint PNe for these conditions Only 45 degrees elevation. Appears in a field which is littered with faint *s. To the NE by 7' is a mag 9*. Appears basically as a translucent disc with an indefinite central hole. Using A.V it occasionally seems annular. In the SW corner of the halo it seems there is an enhancement in the form of a slightly brighter curved streak tracing inside the outline of the outer halo. This enhancement is only slightly brighter than the balance. 90"-100" diameter. No central * visible. Not seen without the filter.
NB the filter was a Lumicon UHC (narrowband) which passes both doubly ionised Oxygen and Hydrogen-Beta lines. I'm trying to remember who put me on to this one because it is rarely found in most of the main-stream atlases. From memory, I believe it is the faintest integrated magnitude PNe in the whole NGC (please correct me if you know better) -- not absolutely certain on that one.
There is an image of it taken by Steve Quirk with 31cm and a G-star camera here:
As for IC 4191, this was my impression with 25cm in 1998 from suburban Engadine with a ZLM about +5.0:
x138 21' TF + x276 10' TF. Mag 10.7 Size 5". Very difficult to distinguish from a *. Follow Hartung's directions. 9' N of a mag 6 deep orange *. Quite minute, < 5". Forms a RA Tri with a couple of *s to the S and E. Disc surrounded by a tiny amount of LSB haze or could be sky haze??. Disc brightens to centre. No central *. Circular. Turquoise without filtration.
Must go back soon and re-observe all three with larger aperture and a variety of filters -- in a month or so hopefully.
NGC 4071 : RA and Dec
Oops, it was late when I posted that 
NGC 5189 is certainly the most intruiging PN in the sky! No other PN anywhere in the sky comes close to its visual structure and detail that shows in the eyepiece. It would be a spectacular sight from dark skies. The transparency during the night was pretty ordinary and I was extremely tired so overall I didn't see as much as I probably would've. 
Also, external glare interfered with the obs, I'll have to throw a dark hood over my head and fashion a dewshield for the front of the 12" dob 
