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Bound and determined : Horsehead thru a ten..BUT..

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#76 blb

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Posted 01 December 2012 - 05:50 PM

...it is an object that is much more dependent on sky conditions than aperture when it comes to detectability.


How True! If you are not at a really dark sky site with good transparency, well you probably will not see IC 434 and if you can't see the nebula, well, you will not see the dark nebula silhouetted against the nebula. But if all goes well and you have the conditions (darkness and transparency) that you need to make this observation, then a good 4-inch refractor will do the job just fine.

#77 rannoch

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Posted 02 December 2012 - 12:30 PM

May I ask what the best eyepieces size is to have the best chance to see the HH? I have a 12" Meade F/10

I have a 2" H-Beta filter and soon to own a 1.25"

What 1.25" and 2" would be be best for my scope?

#78 David Knisely

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Posted 02 December 2012 - 01:54 PM

May I ask what the best eyepieces size is to have the best chance to see the HH? I have a 12" Meade F/10

I have a 2" H-Beta filter and soon to own a 1.25"

What 1.25" and 2" would be be best for my scope?


You will need a fairly long focal length eyepiece to get into the proper exit pupil range to detect the Horsehead. Probably something in the 35mm to 55mm focal length range for an eyepiece would get you there. A good 40mm Plossl or 55mm Plossl might be good places to start. Clear skies to you.

#79 rannoch

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Posted 02 December 2012 - 02:27 PM

Hi David

Perhaps a Televue 40mm 1.25" Plossl and a 2" Televue 55" Plossl?

Or even a Meade 4000 Series 56mm Super Plossl Eyepiece 2"

A lot cheaper

#80 ensign

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Posted 02 December 2012 - 07:00 PM

Hi David

Perhaps a Televue 40mm 1.25" Plossl and a 2" Televue 55" Plossl?

Or even a Meade 4000 Series 56mm Super Plossl Eyepiece 2"

A lot cheaper


I saw a Pentax 40 XL on A-mart recently. I have one and like the views through my 9.25 Edge.

#81 Sarkikos

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Posted 02 December 2012 - 07:12 PM

Maybe a Titan-II ED 40mm if you can find one used.

Mike

#82 KidOrion

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Posted 02 December 2012 - 07:19 PM

Hi David

Perhaps a Televue 40mm 1.25" Plossl and a 2" Televue 55" Plossl?

Or even a Meade 4000 Series 56mm Super Plossl Eyepiece 2"

A lot cheaper


An easy way to figure out what you need would be to plug your scope/eyepiece stats into an Eyepiece Calculator that computes exit pupils (among other things). Useful to have!

#83 blb

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Posted 03 December 2012 - 10:30 AM

Hi David

Perhaps a Televue 40mm 1.25" Plossl and a 2" Televue 55" Plossl?

Or even a Meade 4000 Series 56mm Super Plossl Eyepiece 2"

A lot cheaper


An easy way to figure out what you need would be to plug your scope/eyepiece stats into an Eyepiece Calculator that computes exit pupils (among other things). Useful to have!


It would seam to me that it would be best to learn the formula. Then you could figure it in your head when you did not have access to a Eyepiece Calculator. It is really simple to calculate the exit pupil for any eyepiece.

Exit Pupil= eyepiece focal length/telescope focal ratio

Example: a 40mm eyepiece with a f/10 SCT = 4mm exit pupil



#84 kansas skies

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Posted 05 December 2012 - 04:48 PM

Although I've never seen the actual horsehead form, I have been able to make out some structure in the surrounding nebulosity with a 4" refractor from my rural community (yellow zone) by slowly moving the scope back and forth with the manual declination control. I read somewhere that it's easier to see faint details in nebulous objects if the field is in motion and found that it actually does work - Bill.

#85 Sarkikos

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Posted 05 December 2012 - 04:56 PM

Good idea. I've used that trick to detect faint galaxies and see some structure in them.

Mike

#86 RolandosCY

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Posted 12 December 2012 - 04:21 PM

The brightness of IC434 is similar to that of the Veil.


I beg to differ. It must be considerably fainter. The Veil (eastern half) is easy as pie in any of my telescopes, even unfiltered, but I've never seen a hint of IC 434, despite looking for it on some very good nights in the past.


Clear skies!
Thomas, Denmark

Hmmm. I meant the unfiltered view. Then again, I don't usually check both on the same night.


Hmmm... Finally last night I had a chancve to test my above statement. Under SQM 21.04 (steady!) skies I had The Veil and IC 434 at approximately similar altitude - neither very high. Case is settled: Under similar conditions, in my 18", the Veil (all main segments) were considerably brighter than IC434. My previous statement was gloriously toppled! I guess the fact that by late October I rarely check the Veil and I don't normally bother for the HH until mid December created somehow in my mind the illusion that the unfiltered view of the Veil was similar to that of IC434. No chance. Without filter the Veil was readily visible with direct vision and with structure visible, and in the 31mm Nagler with UHC it became a superbly detailed object. On the other hand, IC 434 was barely visible with averted vision in unfiltered views (provided Zeta Orionis was not in the filed). With the 31mm Nagler and UHC, IC434 was visible with direct vision (including an ill-defined horsehead!) provided Zeta Orionis was kept out of the field. The UHC-filtered view of IC434 was considerably fainter than the unfiltered view of either Veil segment. Adding a H-Beta filter made IC434 more obvious, but still not as bright as unfiltered Veil views.

In another important aspect, I did check the HH visibility with two different eyepieces that gave me a similar true field of view: The TV Ethos 13mm (158x) and the TV Panoptic 19mm (108x), both providing a 0.63-degree TFOV. Using the H-Beta filter, the Horsehead was clearly visible in both eyepieces, but the Panoptic gave a much better, more 3-D view and dare I say, it provided a more detailed image of the HH (the "snout" was more pointy and overall more visible). The Ethos 13 is giving me a 2.9mm exit pupil, while the Panoptic 19 is giving me a 4.2mm exit pupil. The image difference was confirmed by the two astrobuddies who were there with me. So, at least under the good conditions we have had last night, the eyepiece that gave the greatyer exit pupil gave the best image!

#87 Dave Mitsky

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Posted 15 December 2012 - 12:48 AM

I had a rather nice view of B33 last night through an H-beta filtered 22" f/3.6 SDM Dob and a 21mm Ethos.

Dave Mitsky

#88 LivingNDixie

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Posted 15 December 2012 - 09:05 AM

Although I've never seen the actual horsehead form, I have been able to make out some structure in the surrounding nebulosity with a 4" refractor from my rural community (yellow zone) by slowly moving the scope back and forth with the manual declination control. I read somewhere that it's easier to see faint details in nebulous objects if the field is in motion and found that it actually does work - Bill.


Yep. Even just tapping the scope sometimes can make a difference. I want to say I read somewhere that this works because the eye can see things better when there is motion involved of whatever target we are trying to see.

#89 northernontario

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Posted 15 December 2012 - 12:44 PM

I have been after the Horsehead for a few years now. No luck thus far.

I don't like to say I almost saw it....but that was the situation last week. Following all the advice that I have recieved on here over the years, I first found the Flame Nebula. Faint but definitely visible. I then went to Alnitak, and started to follow the faint nebula down to HP 26756, and that's where I loose it. I switched between my Oiii and omega NPB and even tried the light pollution filter, but to no avail. No matter. There are some very pretty clusters and stars in that area.

jake

#90 BillFerris

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Posted 15 December 2012 - 01:01 PM

A true OIII filter renders IC 434 invisible in any aperture. I'm not familiar with the passband characteristics of the Omega NPB. An H-beta is your best filter option to enhance IC 434 and, by extension, make B33 (the Horsehead nebula) more obvious to the eye. A UHC offers modest enhancement. An OIII will make it virtually impossible to observe this object.

Good luck with your pursuit of the Horsehead.

Bill in Flag

I have been after the Horsehead for a few years now. No luck thus far.

I don't like to say I almost saw it....but that was the situation last week. Following all the advice that I have recieved on here over the years, I first found the Flame Nebula. Faint but definitely visible. I then went to Alnitak, and started to follow the faint nebula down to HP 26756, and that's where I loose it. I switched between my Oiii and omega NPB and even tried the light pollution filter, but to no avail. No matter. There are some very pretty clusters and stars in that area.

jake



#91 David Knisely

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Posted 15 December 2012 - 01:55 PM

A true OIII filter renders IC 434 invisible in any aperture. I'm not familiar with the passband characteristics of the Omega NPB. An H-beta is your best filter option to enhance IC 434 and, by extension, make B33 (the Horsehead nebula) more obvious to the eye. A UHC offers modest enhancement. An OIII will make it virtually impossible to observe this object.

Good luck with your pursuit of the Horsehead.

Bill in Flag

I have been after the Horsehead for a few years now. No luck thus far.

I don't like to say I almost saw it....but that was the situation last week. Following all the advice that I have recieved on here over the years, I first found the Flame Nebula. Faint but definitely visible. I then went to Alnitak, and started to follow the faint nebula down to HP 26756, and that's where I loose it. I switched between my Oiii and omega NPB and even tried the light pollution filter, but to no avail. No matter. There are some very pretty clusters and stars in that area.

jake


The DGM Optics NPB filter is a narrow-band nebula filter with characteristics similar to the Lumicon UHC. The NPB has a very slightly narrower primary passband than the UHC, passing both the H-Beta and OIII lines at high transmission, along with a deep-red secondary passband. I have seen the Horsehead numerous times with the NPB filter, although it remains quite faint and somewhat marginal. The view in the H-Beta filter is quite a bit better in terms of contrast however. Clear skies to you.

#92 blb

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Posted 15 December 2012 - 03:13 PM

The OIII filter will NOT work at all, a UHC filter will help some, I will leave the NPB filter to David, He knows and I have never used one. But let's get real here. NO ONE sees B33, it is dust and/or gas between us and IC434 that blocks our seeing IC434. So what you see is the absence of the nebula IC434 that is shaped like a horse head seen in silhouette. What you are trying to do is see the very faint nebula around the absence of the nebula because you can't see B33. If you are having trouble seeing IC434 you will never see the silhouette.

#93 BillFerris

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Posted 15 December 2012 - 04:25 PM

I wouldn't go so far as to say no one sees B33. In my 18 inch, B33 presents as an inky blackness in the form of a horse's head seen in profile. It's an obviously deeper black than the charcoal hue of the sky to the east. This is generally true of dark nebulae. They display a genuine inky blackness in contrast to the naturally lighter hue of the nigth sky.

Bill in Flag

The OIII filter will NOT work at all, a UHC filter will help some, I will leave the NPB filter to David, He knows and I have never used one. But let's get real here. NO ONE sees B33, it is dust and/or gas between us and IC434 that blocks our seeing IC434. So what you see is the absence of the nebula IC434 that is shaped like a horse head seen in silhouette. What you are trying to do is see the very faint nebula around the absence of the nebula because you can't see B33. If you are having trouble seeing IC434 you will never see the silhouette.








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