Defining the Cone Nebula

[MarsG76]

Visually NO, I only tried to image this through a 80mm refractor a f6.25 and it was still dim... I only gave it 1 night of imaging so maybe it needs more time but still if imaging was faint, I can imagine the difficulty of seeing it through the EP.

[clarkpm4242]

On 12/11/2017 at 22:34, scarp15 said:

containing to the south of this star, a dark indentation - this feature is the Cone

Yes.  I have seen confusion around this.  The 'notch' is the challenge.

I know I observed this deep into winter on very transparent nights from Llyn Brenig in N Wales.  About 15 years ago.  This was through my 18" Obsession.  I don't have a record of the filter however, I have  tendency to go for the UHC as I find views much more pleasing than an H beta.

Good luck.  Paul.

[estwing]

I use the UHC..now where's mapstar with that H beta!

[scarp15]

Tonight I will be using a Lumicon - original, 2" H-beta. Do not know what to expect, probably not a great deal, there is a good clear sky forecast up here (perhaps a bit of wind), will try and make the most as the weather is expected to steadily cloud over afterwards.

[faulksy]

hope you had some luck iain

[alanjgreen]

Here is my summary from last night...

 

Cone neb – Here we go! I have been on this target a few times recently and tonight was the night, I was determined and the E21 and E8 were “ready and able”. I starting with the E21 and Hb, moved to the E8 and the E13, finally back to the E21. My description is really a summary of what I saw.

The best combo was E21 and Astronomik Hb. Although the Ethos8 scores a worthy mention and I will use this combo again. Both bested the E13. With the E21, there was loads of nebulosity to see in and around the whole area. I nudged around, getting my eye in on the nebula gas. I swung up and under the cone concentrating on the nebula. Unlike the other night there was now plenty of nebula to the left of the cone so I focused my attention on that as I drifted up to the left side of the cone. Still looking at the gas, I let the cone “come to me” and drift in. The first piece I saw was at the wide bottom of the cone. The surrounding nebula was seen above and beyond the cone. A jagged edge was seen marking the end of the cone. The right edge was teased out with not too much trouble and I did see the left edge more than twice (it has a bulgy like appearance if and when it shows up).  

The view is nothing like the image, there was no bright nebula line. It’s a black edge seen against the dim nebula to the side.

The Ethos8 was a surprise, I only tried it as someone in another thread had had success with a 7mm. The Cone fills the FOV in the 8mm. The right edge was seen but without the help of the surrounding nebula its hard to get your eye in. The E8 brought out the glow around the double star at the tip.

 

From

 

 

[scarp15]

That's great Alan, good to hear of your definitive success. From my location last night, I positioned onto 15 Mon and could easily determine the nebula surrounding this star. I was using a 21E and 13E , H-beta filter, the 13E, x142 (with paracorr) provided the best contrast. Thin traces, patches of nebula abounded within the cluster. I drifted downward to what I believed to be HD 47887, nothing really, no clue to apparent associated nebula, that might facilitate an attempt towards detecting the Cone - at least other than averted imagination. It is possible I was not observing correctly or in quite the right placement. Yours and other observers accounts are reassuring and descriptive, as a useful resource, it would be useful to see observers specific drawings (yes there is the more broad reference on Observing at Skyhound), that are of course is very helpful such as with pursuing the Horse Head. Circumstances were good, but very cold with a sharp wind chill and I had started the process by observing firstly the Flame followed by an observation of the Horse Head, to which I have grown quite accustomed. Later in the session both Orion and Monoceros were better positioned in the South and but for very cold fingers (faffing taking gloves of) and the late hour 1.30am, I thought better of. It was a good exercise in understanding the nebula features in this area, restrictive perhaps based on using moderate aperture, 350mm dob and not necessarily at the darkest sky (approx. SQM 21.3) and also in conjunction with my own visual capability. This could perhaps be considered as a dark horse too far, or else to keep on trying / learning and have another go this winter (bigger scope would help though). 

By comparison, NGC 2264 The Christmas Tree Cluster, to return to with the filter removed afterward is a always a very nice, seasonal and relaxed observation. 

[faulksy]

nice one alan and good effort iain. need to bag this

[alanjgreen]

This sounds like a tall tale but it's true! (Thought I better get that out the way before I begin  )

Last night I had a very big surprise when viewing the cone and surrounding nebula with the 20".

I first tried using ethos21 and Hb filter and had a "usual" experience of seeing the nebula, getting my eye in, moving up to the cone and letting it drift across the view. The bottom and right sides were pretty sharp, the left side did not come. A pretty recurring theme.

However, for some reason I decided to try unfiltered? And this is where it got interesting...

The huge nebula was so easy to see, its edges were clear as day. I panned around and was amazed at how easy it was to see the nebula. I forgot to head for the cone straight off! Anyway, I centered up the cone and as I was doing so, an unmistakable small dark notch was showing in the FOV (unbelievable). It was not triangle shaped, more of a black oblong patch but there it was in direct vision.  

I tried the ethos13 with similar results (but not as good as the nebula itself was not as clear as with the ethos21) but the black notch was there.

I tried the ethos8 and the black background took away the nebula and the black notch was lost in the blackness too.

I tried UHC and nothing much to report with that.

You only seemed to get the edges with the Hb, unfiltered gave a black notch.

I did a double check by trying the flame and horse head with the same combo (e21 unfiltered), the flame was easily seen (but not the full 3 pronged cactus) and I even saw glimpses of the horse head too ( only because I know where it is and how best to find it, it was glimpses of some blackness within the notch area (rather than the full black notch shape) but it was detectable unfiltered!  

Alan