Lesley,
You'll need to use a 10 or maybe 12mm ep. Any smaller and you'll be losing a lot of the light needed to see it.
You've got to come to Astrofest. Lot's of IISer's will be there. It's terrific to put faces to names.
You can book here www.qldastrofest.org.au
Cheers,
Jeanette
small eye pieces are esentual 4 -3 mm??
i have also read somewhere that using a uhc filter is a better filter to use because it is not as strong to to filtering the wave length of light to the h-betta filter, so i could be filtering to much light so i have troube seeing it?
thanks for the info.
Hi,
I mentioned that you needed an EXIT PUPIL of 3mm to 5mm, as ideal. I think you are confusing this with the eyepiece focal length. You get the eyepiece exit pupil by dividing the eyepiece focal length by the F-Ratio of your telescope. Assuming your 10" dob has a focal ratio of between F4.5 and F5.5 ideally you should look to use an eyepiece having a focal length between 15mm and 25mm with about 20mm being ideal. If your scope is a 10"/F5 scope, a 20mm eyepiece gives a 4mm exit pupil which is perfect.
Is there another object in the whole sky that evokes so much emotion and passion than this really quite small, faint poor object? Perhaps "The Pup" (Sirius B) is the only one that comes close.
If the shape of the dark nebula (B 33) didn't so closely resemble the outline of certain chess piece, there'd be a lot, lot less fuss over it -- really who'd bother? If fact I'd wager that but for the Horsehead, they would sell very, very few H-Beta filters.
Fact is, rightly or wrongly it is just one of those "gateway" objects that people just have to see -- kind of like a ticket to membership into some special club. I know whenever I'm with others and it's in the eyepiece and I say "Would anyone like to look at the horshead?" -- people come running. Its a strange thing.
Sadly, I think it is this iconic status it holds that causes so many "questionable" claims about who, when, where and with what optical aid it can be seen. I have been waiting for someone to claim to have seen it naked eye (with or without filter).
I can only speak for myself (a reasonably experienced observer with pretty good eyes) and my own experience, but I've never seen it in any aperture less than 10". In my old 10" f/6 is was very difficult in excellent conditions both with and without a UHC filter. I never saw the chin - just an ill-defined dome-shaped dark intrusion into IC 434. With 30cm it was a bit easier but by no means simple or easy.
In comparison to smaller apertures, with 18", excellent conditions _and_ a H-Beta filter, for me it is a pretty simple object. I can see the "chin". Without the filter the whole thing is somewhat less distinct.
Based on what _I_ can see and _my_ experience, I would treat with considerable scepticism, any report of observing it in apertures less than 15cm -- no matter what. Maybe I'm wrong. But I can only say what I think based on what I can see. That's not to say they're lying -- I'm just very sceptical based on my experience.
The most important factors to get in your favour (as John B said) are dark (read pristine or almost) skies, clean, contrasty optics, 4-5mm exit pupil, aperture and (for apertures over 10") a H-Beta filter. In the absence of a H-Beta, a UHC or narrowband filter is helpful, but the H-Beta is clearly a much superior filter on this object. Keep Zeta Orionis out of the FOV!!!
The other important factor to take into account is _experience_ -- an experienced observer is much more likely to know what to look for and is therefore more likely to see it an a given aperture compared to inexperienced eyes.
To answer your initial question Les, yes a 16" will show it. If you get all the above factors going in your favour, your chances will be significantly improved. Best of luck with it!
Hmmm ... I think this deserves an article somewhere soon.
I can see the Horse Head Nebula live in real time on the small screen using my Gstar-Ex camera and a 100mm lens.
No filters needed.
This camera is a real boon for those of us with poor eyesight.
I have been waiting for someone to claim to have seen it naked eye (with or without filter).
Of course I've seen it with my own eyes, unassisted. But then again, I did have my left eye replaced after that horrific crash I had in that experimental rocket plane I was flying that day
Is there another object in the whole sky that evokes so much emotion and passion than this really quite small, faint poor object? Perhaps "The Pup" (Sirius B) is the only one that comes close.
I'm surprised that NGC 1999 isn't more "famous"! That T-shaped dark cloud is quite visible even under my suburban skies. I'm sure under dark skies it would be a striking sight - a hell of a lot easier than the Horsehead!
Lots of interesting challenges here for those dark sky observing opportunities...
Barnard's Loop, Witch Head nebula, Cone Nebula, Seagull Nebula and Sharpless 2-264.
7) Did the person use a high quality eyepiece with good light throughput and contrast.
Great post John, just the sort of thing relative newbies like me are after.
With respect to point 7 above, what type of eyepiece is best for throughput and contrast? Personally I love Naglers and Pans, but sureley there's too much glass in them? Would an orthoscopic be better? Or even a Plossl? Something obscure?
My best views of it have been with a borrowed Zeiss 25mm aspheric, aka the "magic nebula eyepiece". This same eyepiece has also given me the best views I've had of the Rosette nearby in Monoceros. It has just three elements. Also it produces a 5.4mm exit pupil in my scope, which is an important consideration (point 6 on John's list of Horsehead prerequisites).
ps as per your categories below: I think this eyepiece could safely be classed as "obscure".
Last edited by PhilW; 27-06-2008 at 04:00 PM.
Reason: grammar; addendum
Great post John, just the sort of thing relative newbies like me are after.
With respect to point 7 above, what type of eyepiece is best for throughput and contrast? Personally I love Naglers and Pans, but sureley there's too much glass in them? Would an orthoscopic be better? Or even a Plossl? Something obscure?
Regards,
Jason.
Hi Jason,
Certainly the philosophy that less elements is better for contrast and throughout holds true. The eyepiece Phil mentions, the Zeiss Aspheric as well as Zeiss orthos, Zeiss Monos, TMB Monos etc are the premium choice, but not really necessary. The point I was trying to make is that something like a $20 plossl isn't going to help your cause by comparison to a decent eyepiece like a UO HD ortho, Televue Plossl or Tak LE for instance. Similarly a 20+ year old Meade S4000 UWA or 13mm Nagler T1 isnt going to cut it by comparison to say a 14mm Pentax XW or 13mm Nagler T6 with newer coatings and glass types. The difference between simple eyepieces and multi element widefields, that existed even just 20 years ago, has been dramatically narrowed with modern glass types and coatings. Recent manufacture high quality widefield eyepieces like Pentax XW's and Nagler T5's and T6's are not far behind the high quality simple eyepieces. By comparison the modern Pentax XW's and Nagler T5's and T6's are a noticeable step ahead of the early Naglers, Panoptics, Televue Widefields and Meade S4000 UWA and SWA's due to modern coatings and glass types. Years ago, the difference between a widefield erfle for instance and a high grade ortho or plossl was enormous. Today the difference while still there, has narrowed a lot.
Don't feel handicapped with a top grade widefield. It isn't far behind a top grade simple eyepiece.
This image shows the HH well. http://www.pbase.com/gregbradley/image/99310264
Look for the right angle triangle of faint (mag 13) stars next to the HH when viewing the nebula.
One star is just to the left of the chin, one 2.3' above that and the 3rd star above the right edge of the nebula.
With a UHC filter and a 24.5mm Meade SWA eyepiece I have seen the horsehead many times in the 16" as a subtle darkening of the field if you knew where to look. Not worth writing home about. A borrowed H-beta filter brought it out much better though. Sky conditions and how high it was also made a big difference. Something like Thor's Helmet or NGC3199 with an OIII is a much more spectacular object visually.
I would also add support to the idea that top modern wide field eyepieces with their multicoatings would only lose an imperceptible amount of light compared to those with less elements.
