A Visual Obervation Of Horse Head Nebula.

[AstralTraveller (David)]

About 20 years ago, when I had young eyes, I saw the Horsehead Nebula in a 20cm newt at the ASWA astrocamp at Dryandra (sp?) without a filter. We started by viewing it through a 30cm newt, in which it was very obvious, and then progressed through a 25cm to the 20cm. Some observers could not see it in the 20cm while a couple of (optimistic?) observers reported seeing it in a 15cm schmidt-newt. I'm pretty sure I wouldn't have seen it in the 20cm if I hadn't just seen it in a larger scope.

The skies out there have a very good reputation and that was certainly the case that night. I've tried in a 33cm from outside Wollongong but had no success. I agree that contrast, both in the sky and in the scope, is crucial.

[Karlsson]

Dug around in my observation records, and I found 26 Feb 2000 in Tabangao, Philippines, around 19:20, when B33 was just past culmination (73° Alt). What little lights there were were out: blackout....
-Black sky, a little haze, seeing 3/5
-scope 200mm f/6 Newtonian
-Vixen Lanthanum 15mm EP (80x, 38' TFoV) -
I saw a darkish patch in the right place, with averted vision, but ONLY after my son (13) had told me how and where to look - roles reversed for the first time...
I could not see the distinct shape. It was smaller than I expected; some effort to keep HD37903 out of the FoV. LPR filter was of little use.

I also found records of two earlier attempts that had been unsuccessful.

At the end of the day it's all a bit moot I reckon - if indeed I did see it I don't think I would claim that I observed it...

[glenc (Glen)]

Tony it was a 21mm Orion Stratus. I also saw it again last night with a 8mm Baader Hyperion on the 12" Dob, but it was better with the 21mm.

[ausastronomer (John Bambury)]

Originally Posted by glenc

but it was better with the 21mm.

4mm exit pupil thats why.

I have found that a 4mm exit pupil, or thereabouts, provides the best contrast balance for observing the Horsehead. Thus ANY 1/2 decent 20mm eyepiece is a good choice in an F5 scope. Conversely if your scope is an F8 to F10 SCT or long tube reflector you will need a 30mm to 40mm eyepiece. In addition, any filters you are likely to use to try observing the horsehead deliver optimium performance with a 3mm to 5mm exit pupil.

Cheers,
John B