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lightfever
Pooh-Bah
Reged: 09/27/04
Posts: 1493
Loc: Macomb Michigan
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The nebula doesn't blink out in my 12.5" scope, but does so when I use the 8". I just noticed this a few days ago.
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Mark
Tasco 15-TE 76mm Sky Watcher 80mm ED AT-111
XT8i (with Woden re-figured mirror)
12.5" f/6.3 Dob (Underconstruction)
36mm Siebert, 24mm Pan, 13mmT6, 10mm XW, 4.7 UWA
8.8mm, 6.7mm, 4.7mm Meade 4000 UWA
Various Ortho's, Brandons, Nikon zoom and a Pentax 5mm XO
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 8803
Loc: Beatrice, Nebraska
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Quote:
That is a great sketch (as are your others) - it looks exactly like what I see through the eyepiece of my 10" f/6. Maybe the central star could be a bit brighter, but it is very possible that my memory is flawed. This is one of the best targets that I can't point our scopes at with certainty (the other is the Helix), and I frequently have to look around a bit. I am going to try the x pattern the next time I observe it.
You know, there is a rather funny "power effect" on the Cat's Eye that changes the way the central star appears. At lower powers (say under 120x), the central star at times seems to be quite prominent and easy, yet when I kick up the power to my usual 350+ power to see the faint interior detail, the central star becomes somewhat hard to see. In fact, if the seeing is bad, the star just vanishes in the central glow. What I think may explain this is the fact that the central star sits in a tiny inner ring-like shell close to the center of the main bright oval. At low power, what is being seen is a combination of that central star and the tiny inner shell. When I use enough power to make that inner shell show some size, it no longer highlights the tiny central star's spurious disk, so the star had to sort of "fend for itself". This might not be the correct explanation, but the phenomena does explain why I drew the central star so faintly. At low power, it is fairly prominent, but at high power, it doesn't seem nearly as easy to see. Take a look sometime and see what you think, as this is one interesting object to study. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org
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Hrundi
Carpal Tunnel
Reged: 02/06/08
Posts: 1505
Loc: Estonia
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Quote:
As I said in my post above, not everybody I have observed with can readily/easily get the nebulosity to dim/disappear and the star to POP. I encourage them to stare at the star, and I don't remember anybody who finally was unable to see the effect, though maybe they are humoring me?! If I were you I would give it another go, as it is a pretty cool thing to see. STARE at it, and I bet it will blink for you. One final thing - I have only observed this stuff from rural-ish Vermont with mag. 5.5-5.9 skies. I don't know what I would see in a more light polluted environment, though I do assume that the effect would show even better with darker skies.
I usually observe from 6-7 skies, and I notice dnly slightly more nebulosity with averted.
In fact, I seem to have a lot of 'problems' with planetary nebulae, as I see the nebulosities as incredibly intense bright patches, making the central stars hard to spot. Cats eye, x50, I couldn't see the central star at all. The nebulosity completely overpowered it.
I also never see a clear dark space in the middle of m57, as the nebulosity is so powerful, that while visible, the ring shape isn't entirely striking.
With m27, I also have trouble seeing the central bar thinning in the middle, since it just seems like a very bright, thick bar to me.
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lightfever
Pooh-Bah
Reged: 09/27/04
Posts: 1493
Loc: Macomb Michigan
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The central star has always seemed prominent to me but I have never been able to use powers as high as David mentioned. (Hardly ever get skies that steady) If the opportunity presents itself I will definitely give it a try at 300x +.
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Mark
Tasco 15-TE 76mm Sky Watcher 80mm ED AT-111
XT8i (with Woden re-figured mirror)
12.5" f/6.3 Dob (Underconstruction)
36mm Siebert, 24mm Pan, 13mmT6, 10mm XW, 4.7 UWA
8.8mm, 6.7mm, 4.7mm Meade 4000 UWA
Various Ortho's, Brandons, Nikon zoom and a Pentax 5mm XO
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coutleef
Carpal Tunnel
Reged: 02/21/08
Posts: 2139
Loc: Montréal and Saint-Donat, Québ...
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Quote:
The stuff I've been hearing in this thread is odd for me. I've heard it said before many times, and yet I can't apply it to myself.
In my 12", the central star of the cat's eye is hard to pick out from the nebulosity, and the blinking planetary doesn't blink. Is this some eye oddity, or a fairly common experience?
For example, with the blinking planetary, even in direct vision the nebulosity nearly overpowers the central star at x120.
The bliking is obvious to me in my 8" when i do not use a filter. With a filter, there is no more blinking.
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François
Scopes: Nexstar 8 SE with Ron's rail and Denk S1 Powerswitch. EPs list is on my Bio.
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4333
Loc: Ireland
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Yes, the blinking effect is very dependent on aperture and magnification. I get a good blink from the Blinking Planetary with an 8" at most magnifications, but only at very specific magnifications with a 16".
IC5217 blinks well in the 16" up to about 300X.
NGC1535 blinks at 510X in the 16", but there it's between the inner and outer shells, rather than between the shell and the central star.
On the original topic, I'm one of the "not much color" guys. Lots of nice detail in the Cat's Eye, but limited color below 300X and none above.
-- Jeff.
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Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-125 / AP1200GTO Tak Mewlon 250 / AP600EGTO
Edited by Jeff Young (09/04/09 04:30 PM)
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dpwoos
sage
Reged: 10/18/06
Posts: 219
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Another great sketch! In many ways I enjoy these sketches more than photos, because these depict the objects as we (can) see them, whereas photos are another thing entirely. Maybe this is the wrong forum, but I would like to read how you folks go about sketching a planetary, i.e. where do you start and in what order do you add the details.
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lightfever
Pooh-Bah
Reged: 09/27/04
Posts: 1493
Loc: Macomb Michigan
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I agree regarding the sketches and how they represent what is seen in the EP.
Hats off to the guys and gals doing the drawings. 
I have never tried to do one, and don't think I have the patience.
To me the Cats eye looks green and the blue snowball looks blue. I guess I'm lucky that I can pick up these colors.
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Mark
Tasco 15-TE 76mm Sky Watcher 80mm ED AT-111
XT8i (with Woden re-figured mirror)
12.5" f/6.3 Dob (Underconstruction)
36mm Siebert, 24mm Pan, 13mmT6, 10mm XW, 4.7 UWA
8.8mm, 6.7mm, 4.7mm Meade 4000 UWA
Various Ortho's, Brandons, Nikon zoom and a Pentax 5mm XO
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dpwoos
sage
Reged: 10/18/06
Posts: 219
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I am sure that patience is required to create these great sketches, but in my experience that same patience is required to observe fine/faint detail. In my astro club, there are a lot of folks who I don't think spend nearly enough time at the eyepiece, allowing their eyes and brain to learn the view. On another thread, I got beat up a little bit for saying that I didn't believe/accept certain claimed observations. In fact, in my club it is often the case that my claims are thought to push the boundaries. That is fine, and everybody has their own believe/accept threshold. However, some of the skeptics don't spend more than a minute or two studying the view before they say that they don't see whatever, and that is that. In my mind, that hurts their credibility. I have noodled with the idea of sketching myself, as not only would I learn something about sketching/drawing but I think that I would also further hone my observing skills.
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4333
Loc: Ireland
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Quote:
I am sure that patience is required to create these great sketches, but in my experience that same patience is required to observe fine/faint detail. ... I have noodled with the idea of sketching myself, as not only would I learn something about sketching/drawing but I think that I would also further hone my observing skills.
I highly recommend it. Sketching has certainly increased my observing skills. But I also find that it's very relaxing and that I enjoy sessions in which I sketch more than those in which I don't.
Cheers,
-- Jeff.
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Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-125 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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Tim L
scholastic sledgehammer
Reged: 12/17/08
Posts: 919
Loc: Austin, TX
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Quote:
Another great sketch! In many ways I enjoy these sketches more than photos, because these depict the objects as we (can) see them, whereas photos are another thing entirely. Maybe this is the wrong forum, but I would like to read how you folks go about sketching a planetary, i.e. where do you start and in what order do you add the details.
Dpwoos,
Here's a great link to another CN thread about sketching PNs. Wow. I'm really impressed at all the work that goes into everyone's beautiful sketchwork. It's a great way to combine 2 hobbies into one!
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Tim
Zhumell Z10 dob
Meade 60mm refractor
Zhumell 1.25" eyepiece and filter kit
Zhumell sky-glow, UHC, and OIII filters
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CounterWeight
Carpal Tunnel
Reged: 10/05/08
Posts: 1621
Loc: PDX chronoplast
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This a reply to the op, but also other in thread. Sorry but i still forget and reply says to previous poster 
I've recently gone from using a C11XLT sct to my 160ed for visual and image. The 80 remains a guider or only wide field. Am re-calibrating how I see things and useful powers given night and atm / luna factors. Whatever the apeture this smaller planetary, the 'blur' of it compared to nearby stars a giveaway, n this even in my white zone. Has always seemed light blueish to grey bluish.
Magnitude: 8.30, Size: 22", Mean Surface Br. 14.7 Mag/arcsec^2
I usually drop in on at least one of these a night to sort of calibrate my seeing /sky. As commented the choice of ep/mag can have great change in way is perceived, I will usually go lowest (sweeper) to highest power and drop down to get best 'overall' luminosity/detail/color for fov/mag. Use of a good filter can be a plus but am finding not always required. I think planetary nebs, esp this sized and smaller are a real treat to find and explore - more so than fuzzy galaxies as they often have more color / color gradient / hue / definition and shading, and there are a lot of them.
I agree that the sketchings are a very much better resource about 'at the eyepiece'.
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Clear skies - Jim
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CGE (Constant Get Errors), A-P Mach1?
Onyx 80ED, Tak FS-128, TEC APO160ED
CCD: Orion SSPDSCIv2, SSI3, SSAG
diags, ep's, tubes, filters, Binocs
My CN Image Gallery
Experience is a difficult teacher, it gives the test first, and gives the lesson later
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