This is one weird planetary nebula. The central star is way off center. It is the faint blue star left and a bit up from a yellow orange star that's quite obvious in a dark area above most of the HII filaments. The most common theory I find says that it is moving rapidly through the interstellar medium to the southeast (down and to the left). This motion creates a bow shock making the leading edge far brighter than the rest of the nebula partly from the shock and partly because it is pushed back nearer the ionizing central star. Don't confuse this one with the rather similar appearing Medusa planetary nebula. That one has the central star in the center where it belongs but otherwise looks much like this one. The Luminosity image was made from 2 30 minute H-alpha frames and 2 red frames as was the Red frame but the H-alpha was reduced to 30% in the red frame. Green was 2 10 minute shots plus 5% H-alpha and blue 2 10 minute frames + 10% H-alpha (using the two H-alpha frames). Taken with my 14" LX200R on a Paramount ME using my STL-11000XM CCD.

Rick

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Very nicely done Rick. Interesting object! It makes one wonder what would cause such a seemingly unbalanced expansion. Any thoughts?

I gave the explanation I found in the post above. It is moving rapidly though the interstallar medium. It isn't that the expansion didn't start out even but that it is being pushed back by its own high speed motion. This is why it is so bright on that side. The bow shock energy increases its emission intensity besides the central star being closer to that side. Space isn't empty. Give a bubble enough speed through it and the interstellar gases will push back.

Rick

Rick,

Great image and great description. Are you even using the cooler in the camera these days?



--Andy

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Observatorio de la Ballona

You have to use it for best noise reduction. The temperature drops up to 5C during an exposure. That would make matching darks very difficult causing unnecessary noise in the image. I set it at the nearest temp at least 10C below ambient that I have in my dark library. While you can calibrate to a known temperature using darks and bias frames taken at a different temp I prefer to take all shots at a temperature I have good darks taken at. This removes the need for a bias compensation and to me gives lower over-all noise in the final image. But even matching to a temperature doesn't work unless the image was taken at a stable known temperature. Letting the atmosphere set the temp prevents good noise reduction. Going colder than 10 below ambient has the problem that the front (side toward the objective) of the optical window freezes over, even with the extra heater I got from SBIG. The air on the back side is kept dry as it is a mostly sealed chamber. But in winter the front side can get so cold it drops below the dewpoint and your imaging is cut short. Even at 10C below ambient I've had it frost over on me in a place or two. This leaves a hole in the image. Quite a pain.

Rick

Simply Awesome,Beautiful and Outstanding!!!. Rick you have another keeper there Also thanks for the info. Clear Skies

Yes, consistent temperature is needed for proper reduction. Are you able to use darks for a long period of time or do you renew them periodically? I've kept mine on my ST-10 for over a year and they seem ok, but I haven't done any imaging yet to check it out . But the new computer is in the observatory and it's talking to the mount; the camera is next if only the pesky low clouds would go away.

I often have a lot of dew -- everything gets damp. One night quite a while ago the inside of my diagonal fogged up. Now I use lots of dew heaters, and haven't had any troubles inside the camera (or on the front glass). But I don't get much below 32F here...

--Andy

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Observatorio de la Ballona

Very fine photo Rick! Nicely done.

-Veeger

Excellent, Rick!

Tom

Excellent as usual Rick. Is that a small edge on spiral galaxy in the extreme lower right corner?

Kind regards
Matt.

That is 2MFGC 01144 (LEDA 137850) at about 230 million light years. It seems to have a condensation on it or maybe a second galaxy. I can't find anything on it however.

Rick