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Last (almost) attempt at the horsehead nebula


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Weather conditions were just about ideal one weekend late in Jaunuary. A cold front had passed through on Thursday with rain and high winds. Clouds were threatened for Sunday, but that was no problem as I'd intended to try again for the horsehead nebula on Friday and Saturday. Friday was great, but Saturday was better. When storm systems line up over us as they do, the time between can bring amazingly steady skies, even on the desert floor.

I set up the 20" F/4.5 newt on the platform just to the south of my garage. I only had one target, so it didn't seem useful to move it all the way over to the dome. After an easy alignment I was ready to go. Started off with the 40mm just to gain the frame of reference. (The details were teased out with the 19mm Ortho and an 8.8mm Meade UWA.) Yup, Alnitak, the Flame nebula, and the arc of stars that frame the HH. These start at Ngc 2023, a reflection nebula east and slightly north of the HH. (Incidently, the HH is known as Barnard 33, or B33, and the emission nebula behind it is IC 434.) From Ngc 2023 the stars are SAO 132451, SAO 132438, SAO 132 437 and SAO 132452. These are just east of the multiple star Sigma Orionis and north of SAO 132 441.

IC 434 extends south from Alnitak, starting out wide and narrowing as it extends south. On the eastern edge is a denser region that forms a sharp boundary between IC 434 and B33, which actually contains more dark dust and molecular hydrogen than just the HH. The gas is quite bright when compared to the dust, but extremely faint when compared to the glare of Alnitak and most of the other stars I've mentioned.

Following this knife-edge of gas south, I see what looks like a gap in the brightness. Just a tiny little notch. This notch is the HH. Smaller than expected, I am still unable to detect the horsehead shape. All I can see is an indistinct break in the brighter gas, and the two stars that appear in photographs on either side of the neck. Not the neck itself, just the stars

The best I can do is say yes, I've seen it now. But it was almost as exciting a target as M40. And, even if conditions were excellent, perfect, stupendous, I wouldn't bother with it again.

Well, maybe from Mauna Kea, next time I'm there.

It's much, much better in pictures.

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Congratulations on seeing it! If the clouds clear any time soon then I'll have a go at it with my new 12" but it sounds a struggle even with your awesome scope. What limiting mag do you have at your site? I've heard of the Horsehead being seen with an 8" using an H-beta filter so maybe I'll need to fork out for one of those if I'm ever to see it. One of those things you see for what it is rather than what it looks like, I suppose.

Andrew

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Andrew, I've heard of observations of the HH with small scopes too, but I remain somewhat skeptical of these, especially having failed myself in larger instruments. I suppose "averted imagination" plays a part. :( The naked eye limiting mag here at Stone Haven is ~6th magnitude. I haven't done a careful estimate through the 20" eyepiece yet.

Janos, if you know what to look for, I'd imagine the HH is possible in a 16". I think Andrew got it right, though, "One of those things you see for what it is rather than what it looks like".

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I've heard of the Horsehead being seen with an 8" using an H-beta filter...

I've heard of Amateurs seeing it with moderate scopes too, Andrew. In fact, my friend Jeremy saw it with a 6" Newtonian and an Ultrablock filter. Granted, his sky conditions in Flagstaff Arizona are much better than you or I have, but it'd be fun to try. :lol:

And congrats on your sighting, Steve! You didn't mention using a filter, though.. maybe that's why it's been so difficult for you?

EDIT:

Andrew, I just read a report about seeing the HH with an 8" scope and thought it might be of interest to you (Dave has an excellent observing reputation).

LINK

Edited by Talitha
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Very encouraging!

I just upgraded to a 12" and will certainly have a go at the HH with that, though the Moon was near Orion the other night when I got out for my first dark-site session so I didn't bother then.

Still holding out from buying that H-beta filter. And no matter how underwhelming the object itself may be, It would be so nice to be able to tick it off some day!

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Helen,

I have used many filters in attempting this object, H-A, H-B, UHC, OIII, colored glass, aka Wratten, Johnson V, Johnson B, Johnson R and so on ad nauseum. Scopes used have been everything from my trusty C8, 10" Lourie-Houghton, (in which we were easily seeing globulars in M31), 12" Newt, 6" Takahashi, 17" F/6 Newt, on up to a 22" Dall-Kirkham, (SP?) and a 25" F/5 from the Naval Observatory outside Flagstaff, not to mention a couple other professional scopes. It's quite clear to me now that I have seen it, probably many times, but have managed to overlook it. As I describe in my report, it's a matter of noticing it as the tiny break in brightness in that strip of glowing gas, rather than the well-defined object seen in photographs.

I doubt I'll try it again unless conditions are perfect.

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It's quite clear to me now that I have seen it, probably many times, but have managed to overlook it.

I doubt I'll try it again unless conditions are perfect.

Yep that's what I thought all along, and I'm genuinely happy that you' were able to check this one off of your list, Steve.:lol: Now that you know what to look for, I bet it'll be easier next time... even if conditions aren't perfect. :blob8:

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