The Cosmic Owl - A Closer Look

[ChristianR]

One of the fainter objects in Messier's catalogue is the planetary nebula M97. About 2600 light-years away, the object is located at the bottom of Big Dipper's bowl.

Its round shape together with the placement of two large, dark "eyes" do suggest the face of an owl. Under good conditions it was never an issue to observe the "eyes" using my 12" F5 dobson. What I never managed until recently was to see the central star.

Last week in the Alps I'd very good transparency and good seeing conditions. I was able to see the central star using averted vision (about 50% of the time). The observation was confirmed by other 3 colleagues (Uwe, Frank and HaJü).

Here's the sketch I took:
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I used an exit pupil of 1.8mm (167x) to get out some details related to the eyes. The central star appeared using higher power (300x) having an ep of 1mm (I didn't use any filter).

Having a closer look to deep images of the owl, there are two more stars which should be reachable with a little bit more aperture. I was not able to spot them, even if they seem not to be much fainter compared to the central star.

But this isn't the end of the story yet.
Looking to the deep image of capella observatory (see link), there are more very, very faint stars.
http://www.capella-observatory.com/ImageHTMLs/PNs/M97.htm

They seem to be outside of what can be visually reached?

However, I'd be interested in what are your experiences with the cosmic owl, whatever aperture you may be used.


ps:
About 4' southeast of the center of M97, there is the faint galaxy PGC 34279. I didn't note it but the galaxy should also be within the range of medium-size scopes.

[Ivan Maly]

Excellent description and sketch, Christian. Observing a year ago with my 16" Newtonian from Cherry Springs I made the following notes and sketch. The unusual (bordering on incorrect) feature in my observation is the extreme asymmetry ("peace sign") of the eyes positioning. The eyes are indeed darker toward the SW, and apparently this and the low resolution of my view were responsible for the "peace sign" appearance. The darkening of the eyes to the SW is visible in your sketch (to the lower left). My sketch was scanned directly from the notebook and is "upside down", as marked with "N" and "W".

"M97, the Owl Nebula, is a sizable soft disk at 45x. It shares the field of the Pentax with M108 to the NW. The pair is wide but acceptably framed. The galaxy is a soft spindle with a starlike nucleus. At 225x in M97, first the asymmetry becomes noticeable, the N half being brighter, then the faint central star, then the sector-shaped eyes, at which time the nebula begins to resemble a partially filled peace sign. OIII filter enhanced the contrast with the surrounding sky, bit does not change the appearance of the nebula. The contrast of the eyes is not enhanced. The central star becomes invisible."

http://1.bp.blogspot.com/-Rj6xgaWYUGY/UUjDW0U-1wI/AAAAAAAAAa0/xXwhzbJHTqE/s1600/2013-03-08+M97.jpg

[Uwe Glahn]

Wow Christian,

first good idea to try the CS with 12" and second - excellent observation of the star! Of course the sketch a very fine too.

I looked in my observing book and find a positive observation of the CS with my 14,5", I noted: "difficult with direct vision, easy with averted vision". I only saw one star within M 97.

And yes, you are right, near M 97 you can find a faint "companion" which is hide near a 14mag star so it is hard to notice the faint glow. But when you know the position it was easy with 14,5". It was always a fun for me to search after the star with an "offset glow" near M 97.

With bigger aperture two other stars are in reach within M 97. They are only a little bit fainter than the middle star and should be visible maybe with the 16"-18" class? Another interesting thing is to look after the differences of the eyes in M 97. Rainer Mannoff (http://www.mannoff.de/zeichnungen/M97.htm) noticed that with a 18" and sketched it. With 27" I could also detect several differences and details within M 97 (sketch with 27" (http://www.deepsky-visuell.de/Zeichnungen/M97.htm))

[aatt]

I have seen the eyes in my 6" F/8 on a particularly good night. I have seen all of that and the central star in my 15" on good nights. It really has to be a good night even with the 15" to see the eyes averted or otherwise. Other than that I have not noticed anything out of the ordinary nearby except for that lenticular galaxy whose Messier number escapes me at the moment. Guess next time I will pay more attention to everything in the field I am usually just trying to see eye to eye so to speak.

[Howard B]

During last summers GSSP, Jimi had his "Central Star" filter which works just the opposite of an OIII filter by blocking the OIII lines. It's designed to reduce the brightness of planetary nebulae so their central stars are more easily visible. Using it with my 28 inch on the Owl, which was quite low in the northern sky at the time, was a shocker as it almost completely disappeared leaving only a faint stain of nebulosity and a handful of stars behind - just the opposite of trying to see stars superimposed on the planetary!

[ChristianR]

Hi Ivan, Uwe, Howard, "aatt",

many thanks for your feedback, I appreciate it!

[hajuem]

Hi Christian

Very Good Sketch and Observation!! IT`s was a specielly night with us and i hope for other night`s at february new moon!!

My sketch from April 2013 mit 16 Zoll:

1091

CS Hajü
www.astromerk.de

[Preston Pendergraft]

M97 is one of my favorite objects to observe because it was one of the first few Messier objects I found by star hopping as a teenager. It is fun getting it and M108 in the same low power field.