What size telescope to see The Horse Head Nebula

[Guest]

Done to death this topic over the years I know. But from a dark sky I have no been able to see the Horse Head Nebula with an eight inch Newtonian telescope. I have the opportunity of acquiring a 12 inch Newtonian. Just wonder how I might fare with this instrument in dark skies.

[faulksy]

the first time i seen it was with my 14 dob. john has seen it with his 12 dob in somerset, so if you go dark you should see it. you need bortle 2 skys

[Paul73]

Dark sky is what you need. It is almost impossible with my 16” Dob from home, but it has been done using far less from really dark sites.

Paul

PS the horse’s head is possibly the most underwhelming sight in astronomy. Don’t expect too much.

Edited December 19, 2020 by Paul73

[Waddensky]

I've read reports of experienced observers catching the Horse with a 100mm. I think an excellent H-Beta filter, very dark skies and a well-chosen exit pupil are as important as aperture.

[John]

The darkness of the skies and getting the exit pupil right are almost more important than the aperture of the scope I think.

I've managed it a couple of times with my 12 inch dob using a H-Beta filter but it is probably the least distinct target that I have ever observed. 

I use this Jeremy Perez quote often with regard to this target but it is a good one:

"Really, it's like trying to see a little bit of nothing with a little bit of less than nothing resting over it."

 

 

[John]

Edit: I should have added "transparency" to my description of the skies above. Dark and transparent skies are vital. I spent ages getting and staying dark adapted when I managed to see the Horsehead as well. I kept away from any light source whatsoever for about 2 hours. Even turned the reticule of my Rigel Quikfinder off.

Of course the whole thing might be somewhat easier and more of a sight at a truly rural site with skies - say bortle 2/3.

 

[ollypenrice]

Worth remembering: nobody called it the Horsehead Nebula before astrophotography...

Olly

[Paul73]

17 minutes ago, ollypenrice said:

Worth remembering: nobody called it the Horsehead Nebula before astrophotography...

Olly

Although, the “Indistinct Notch of Near Nothingness nebula” is very nearly as catchy.....

Definitely a target for the imagers.

Paul

[ollypenrice]

14 minutes ago, Paul73 said:

Although, the “Indistinct Notch of Near Nothingness nebula” is very nearly as catchy.....

Definitely a target for the imagers.

Paul

I've seen it at the EP a couple of times but it just appeared as an oblong of darkness (larger than expected) against slightly lesser darkness. One SGL member said he'd seen it like the chess piece but most just describe an oblong notch. It certainly isn't the most tantalizing ultra-faint target in my personal canon of obscurities. My own ultra-faint obsession is the 'beckoning finger' feature in M42. I can just - just - get it with the right exit pupil.

Olly

[Ships and Stars]

I've managed the horsehead with a 12" dob at a 21.75 site near me but it was faint. Astronomik Hb filter. I was actually using a bit too much magnification. 17.5mm Morpheus. A 25mm eyepiece would have offered a larger exit pupil (5mm vs 3.5mm for the Morpheus). Next time I'll use a simple 25mm plossl. 

I have seen it numerous times with my 20" dob under dark skies, the last and best view was in October this year from a really dark site in the Cairngorms, but it was low on the horizon. Still, I could make out the nose and back of the head. 

Seeing it in the big scope made it easier to see in the smaller one, knowing right where to look.

I have some 20/40x100 obsy bins that take filters. My goal is to see it in those from a dark site. UHC on one side. Hb filter on the other. I think it's possible.

I caught a very, very slight hint of B33 against IC434 with filtered 15x70s that night in October, but no HH. 

As John and others have said, dark, dark skies and excellent transparency, the right exit pupil and with that, the 12" ought to do the trick but it will be very subtle.

The 20" will make it directly observable (but still subtle) under dark transparent skies, but I've never seen it from home in the 20" under 20.35 skies with excellent transparency. That's another goal.

A hood to block out stray light and excellent dark adaptation are essential in my book.

Edited December 20, 2020 by Ships and Stars

[jetstream]

My 10" dob shows it from dark skies but it was a big challenge for me at first with this scope. The 15" makes it so much easier, however, dark transparent skies are a must or forget seeing the HH IMHO.

Must add I only see a notch, no head even in 24".

Edited December 20, 2020 by jetstream

[jetstream]

5 hours ago, ollypenrice said:

My own ultra-faint obsession is the 'beckoning finger' feature in M42. I can just - just - get it with the right exit pupil.

 

Olly, what feature in the circle are you talking about exactly? I'm intrigued actually as I too like to dissect M42.

[VNA]

Hello:  On a different forum I saw a beautiful image of the Horse Head using a 5".

[Sunshine]

Just now, VNA said:

Hello:  On a different forum I saw a beautiful image of the Horse Head using a 5".

I think with regards to an image its a completely different situation, one can image the horse head in a much smaller scope than what it can ever be seen in visually.

[ollypenrice]

8 hours ago, VNA said:

Hello:  On a different forum I saw a beautiful image of the Horse Head using a 5".

 

7 hours ago, Sunshine said:

I think with regards to an image its a completely different situation, one can image the horse head in a much smaller scope than what it can ever be seen in visually.

It isn't at all difficult to image because its shape is defined by the background Ha cloud it obscures. The eye is not sensitive to Ha light, unlike the right camera which is highly sensitive to it. Since H Beta generally traces the same gasses as Ha, but in a wavelength they eye sees easily, that's probably the best filter for the observer.

8 hours ago, jetstream said:

Olly, what feature in the circle are you talking about exactly? I'm intrigued actually as I too like to dissect M42.

I visualize it as a hole in the pale coloured grey-ish gasses through which a crooked finger emerges, standing out against the much redder hydrogen emission behind it. A similar feature exists directly below it, doubtless created by the same physical processes, but the lower 'hole' is more blurred and the equivalent of the 'finger' much larger and more diffuse. We must remember that, in reality, the Trapezium is far brighter, relatively, than it appears in my image. Multiple exposure lengths have been combined to compress the dynamic range into what the screen will allow. That means that the brightness at the eyepice is already falling off dramatically as you get down to the first 'hole.' By the second there is little to see - at least with my eyesight.

Olly

Edited December 20, 2020 by ollypenrice
Typo

[jetstream]

5 hours ago, ollypenrice said:

I visualize it as a hole in the pale coloured grey-ish gasses through which a crooked finger emerges

Thanks Olly, I see the hole easily but never paid enough attention to try to see more. I'm going to drag the 24" out and play with the mag to see if I can pull it out.

[John]

12 hours ago, VNA said:

Hello:  On a different forum I saw a beautiful image of the Horse Head using a 5".

Hi - I believe that it is not a particularly difficult target to image. Seeing it visually seems to be quite a different matter

[reezeh]

On 19/12/2020 at 10:10, Paul73 said:

Dark sky is what you need. It is almost impossible with my 16” Dob from home, but it has been done using far less from really dark sites.

Paul

PS the horse’s head is possibly the most underwhelming sight in astronomy. Don’t expect too much.

Messier 33 from my garden beats it for underwhelming!

[scarp15]

If you get hold of a 12" Newtonian, investigate the Flame Nebula, there are some very good drawings available as a reference. The same circumstances apply; dark and transparent sky, observe when Orion is nearing the South, become fully dark adapted - do not look at the Orion Nebula before hand. Experiment with eyepieces and perhaps filters. It is a good subject to became accustomed to observing fainter nebula. 

[malc-c]

On 19/12/2020 at 10:10, Paul73 said:

 

PS the horse’s head is possibly the most underwhelming sight in astronomy. Don’t expect too much.

Which is why I went into imaging rather than visual

This was form the middle of a town with an 8" 200P and a Canon 400D DSLR....  I was targeting the flame nebula, but the horsehead can be seen right at the edge

 

[John]

I found these links very helpful when I was initially trying to see the Horsehead Nebula:

https://observing.skyhound.com/archives/jan/IC_434.html

http://www.perezmedia.net/beltofvenus/archives/000379.html

[bish]

Seen it with a 10" (not my 250px), from a dark site with H beta and excellent transparency. It was on the limit for my eyes. Slight difference in contrast. I have seen the flame fairly easily with a UHC from a different site (not so dark) with my scope, but HH not a hint.

[mikeDnight]

 

Can't say I've ever actually seen the horse head for certain, but I have seen IC434 in a 100mm refractor. It was the most difficult DSO I think I've ever detected, and was only visible with averted vision after a lengthy study, with my surroundings being fully blacked out. I felt there was an indication of the notch of black nebulosity that may have been the HH, but couldn't truthfully say if that's what it was.  Looking at the sketch below with averted vision will give some indication of the eyepiece view in such a small scope. The first hint of IC434 appeared as a shard of nebulosity protruding from the star shown in the sketch and pointing towards Alnitak. The lengthy black nebula was very prominent once the shard came into view, which helped to highlight the dimmer bright nebula. The HH, if that's what it was, was an almost indistinguishable, formless notch protruding into IC434. 

The Flame was much much easier in the 100mm than IC434.