Polls

Re: Who Among Us Has Observed the Horsehead Nebula?

EightHHaggis — Thu, 25 Oct 2007 23:23:03 GMT

Here are some anomalous reports of mine, done in extremely favorable conditions at a moderately high altitude mountain top site (3,400 ft) overlooking the Pacific ocean, in northern California. I say "anomalous" because of two things that set the circumstances off from those of many other normal deep sky observers: (1) I've specialized in this object for over 20 years, researched it, published an entire website about it, and by now have probaby seen it between 50 and 60 times; and (2) I have used it regularly for specific tests: of telescopes, filters, eyepieces, and binoculars. I dare say that you can't just INTEND to get it in small aperture telescopes, and go forth and achieve it. No; it is elusive, and shows up when the object is close to the meridian, when sky transparency is best, and when the Milky Way is very clearly viewable in the immediate region. I try it several times during the appropriate seasons, and find that if I obey these rules, there is about a 75% chance that I can see it in SOME telescope, if not every instrument in my collection. But it has shown up in the smallest apertures only occasionally...

1. Evidence of seeing it in 8x42 binoculars equipped with Lumicon h-beta filters (drawing & description) and table of other observations with apertures ranging from 60 to 200 mm: found in this article, part of my Horsehead Project website.

2. Recent test involving 50 mm, 80 mm, and 114 mm aperture instruments: this entry in my observing astro-blog;

3. My last observation, not a very good one, in my 120 mm f/5 Orion refractor, mentioned here in my blog's third test report article about the instrument.

My most satisfying views with my own telescopes have been in a 17.5 inch Dob, and in the last year or so with my C-11 and 10" Dobsonian: H-beta filtered views that were almost as clearly defined as a very good monochrome photo. One of my two or three all-time-best views was in a 7" AP StarFire refractor (with H-beta filter); and I've seen it in other telescopes numerous times with a UHC/UltraBlock filter, and with NO filter at least once or twice.

These views were all at an observing site that is about 10-12 miles (as the crow flies) from downtown San Jose, California. But not just ANY out of town site will do: this particular location is high in the mountains, and my observations were aided by local ground fog that came in below me, cutting off much light pollution. I have rarely been able to see it there with NO fog or low clouds to suppress the lights of San Jose, Morgan Hill, and Gilroy (though on one or two supremely clear nights, I've done it.)

Theoretically it is made visible by dark skies; but I don't find that the ONLY requirement. An observing site I've used that is very dark (7-7.5 NELM) has sometimes failed to yield the Horsehead, due to its low elevation of only 1400 feet. Going up another 2 to 3 thousand feet above sea level really helps!

Even years ago, before light pollution was severe in the region of the Santa Clara valley, Lick Observatory astronomer Gene Harland told me he was unable to see it in the fairly large aperture finders, and the guiding eyepieces, of scopes he used to photograph it. And in the 1980s, I was unable to get it in the old 22" Tauchmann telescope at Lick Observatory, using a UHC-type filter.

Aperture is also NOT the determining factor either. For all practical purposes, the quality of views I've had in the 17, 11, and 7 inch scopes were nearly comparable (except for image scale.)

I was once scolded by somebody that my claims of having seen it in small apertures would just "frustrate" people who couldn't do it themselves. Well: so what? The point is to know what the human eye is CAPABLE of detecting, given enough opportunities to test every potentially satisfactory set of conditions.

Steve Waldee

San Jose, CA.

Horsehead Project Website:

http://home.earthlink.net/~astro-app/horsehead/index.html

Re: RE: RE: Who Among Us Has Observed the Horsehead Nebula?

johnm — Mon, 08 Oct 2007 01:42:29 GMT

My success with B33 has been really mixed and I've never had a really good view yet. Using my 12.5" f4.5 with a variety of EPs I've had teasing glimpses. Even on nights when I can bring in IC434 very well. I think somre of the best out here with my dark sky have been without any filter. I'm now setting up a 6" f8 refractor, I'll have to see how it performs.

Re: RE: RE: Who Among Us Has Observed the Horsehead Nebula?

DaveMitsky — Sun, 07 Oct 2007 20:53:03 GMT

MaddCow wrote:
DaveMitsky wrote:

It was possible with a 20" Starmaster under absolutely superb conditions. An H-beta filter is by far the filter of choice, however.
Dave Mitsky
Yea. IC 434 is almost entirely H-beta emission. A good OIII filter- NOT a Tele Vue OIII and maybe not a Meade OIII- will block so much H-beta that the horeshead will be far more visible unfiltered than with an OIII. I can see the Horsehead unfiltered at the Conecuh National Forest, but if I remember right, it either entirely or almost completely disappears when viewed through my Lumicon OIII.

John,

Why do you dispute my word? The Meade OIII filter passes the H-beta wavelength and B33 was clearly visible, to my surprise, thorough the 20" Starmaster belonging to Gary Honis at Cherry Springs State Park on the occasion I mentioned previously.

Dave Mitsky

Re: RE: RE: Who Among Us Has Observed the Horsehead Nebula?

armchairal — Sat, 06 Oct 2007 14:27:40 GMT

Sorry this was to Dave not Bill. I thought this might bring back some memories for ya. Seeing that Im getting the filters soon I thought I would bring it back up seeing as it was posted from someone still here, otherwise I would have just started another post. Im just hoping to see SOMETHING of this neb, with these filters because I sure can`t otherwise

Re: RE: RE: Who Among Us Has Observed the Horsehead Nebula?

Bill Weir — Sat, 06 Oct 2007 05:22:11 GMT

It's interesting to see this thread resurface all these years later. Since that time, a lot of astro-water has washed under the bridge.

I actually looked into what filter was in the 31mm Nagler that night and it turns out it was an Ultrablock. It makes sense now why we were able to see it the nebulosity.

I also now own an H-Beta filter, and my view of that area has change a lot. I've been able to detect the notch of B33 with as small an aperture as 70mm from my back yard, where on a good night the NELM can reach 6.7 (SQM 21.3). On one exceptional night at the observatory just down the road, using my 12.5" dob, the Horse Head shape was clearly visible without any filter. Using the 25" inside the dome at the observatory and an H-Beta filter the dark nebula looks just like a chess piece.

Bill

Re: RE: RE: Who Among Us Has Observed the Horsehead Nebula?

MaddCow — Thu, 04 Oct 2007 05:03:50 GMT

DaveMitsky wrote:

It was possible with a 20" Starmaster under absolutely superb conditions. An H-beta filter is by far the filter of choice, however.
Dave Mitsky

Yea. IC 434 is almost entirely H-beta emission. A good OIII filter- NOT a Tele Vue OIII and maybe not a Meade OIII- will block so much H-beta that the horeshead will be far more visible unfiltered than with an OIII. I can see the Horsehead unfiltered at the Conecuh National Forest, but if I remember right, it either entirely or almost completely disappears when viewed through my Lumicon OIII.

Re: Who Among Us Has Observed the Horsehead Nebula?

MaddCow — Thu, 04 Oct 2007 04:57:56 GMT

From the Conecuh National Forest, a bortle scale 2 site, I can see the Horsehead nebula in my 4" refractor with an H-beta filter (f/6.9 scope and 27mm Panoptic, whatever that works out to). I can also fairly easily see it WITHOUT a filter in my 18" scope (75X). WITH an H-beta filter through the 18" scope, not only is it an easy object, but it's actually quite striking and pleasing to view.

From my light polluted limiting magnitude ~5.5 backyard (bortle scale 5-6), I can still see the Horsehead nebula with the H-beta, but instead of it appearing as the classic horsehead shape, it is washed out by light pollution so much it just looks like a notch in IC 434.

Re: RE: RE: Who Among Us Has Observed the Horsehead Nebula?

DaveMitsky — Wed, 03 Oct 2007 08:30:36 GMT

It was possible with a 20" Starmaster under absolutely superb conditions. An H-beta filter is by far the filter of choice, however.

Dave Mitsky

Re: RE: RE: Who Among Us Has Observed the Horsehead Nebula?

Bert — Wed, 03 Oct 2007 02:56:38 GMT

Wait it's possible with a Meade OIII filter? I have the visual back Meade OIII(still planning on getting a UHC filter)

Re: Who Among Us Has Observed the Horsehead Nebula?

tasco-60mm — Wed, 03 Oct 2007 00:19:10 GMT

never seen it- used a 12" dob, 23mm axiom and 2" 32mmEP's- filters tried were the celestron LP, baader M&S filter, with these 2 also being stacked- i would need either an extremely dark site or an H-beta from my location- i can image it rather easily- however after imaging it, i know exactly what to look for, so ill attempt observing again when i get an 'ideal' night for all its worth in my LP

Re: Who Among Us Has Observed the Horsehead Nebula?

armchairal — Wed, 03 Oct 2007 00:02:50 GMT

I have never seen it yet but will soon, I hope. Ordered the Lumicon UHC, Oxygen III and H Beta filters this week. Can`t wait

RE: Who Among Us Has Observed the Horsehead Nebula?

Bill Weir — Mon, 08 Dec 2003 21:06:48 GMT

Thanks for the info Dave. Next time I think I'll try using the 10'' f7 eq newtonian at the observatory I go to using my ultrablock. What magnification do you suggest? I want to try as small as aperature as possible. I like the challenge.

RE: RE: Who Among Us Has Observed the Horsehead Nebula?

DaveMitsky — Mon, 08 Dec 2003 20:08:16 GMT

Bill,

An O-III filter will kill any chances of seeing B33 since most of them do not pass H-beta light. The only exception I know is the Meade O-III, which I wouldn't recommend anyway. A narrowband filter such as the UltraBlock does allow transmission of H-beta.

I've seen the Horsehead Nebula a number of times through apertures ranging from 13.1 to 36 inches. Twice I've seen it without filtration, using 14.5 and 20 inch Starmaster Sky Tracker Dobs. The H-beta filter is definitely the one to use but I have seen B33 through UltraBlock and UHC narrowbands and the Meade O-III filter that I mentioned.

Three of the locations were dark sites in Pennsylvania. The other occasions were at the Winter Star Party in the Florida Keys where the seeing is exceptionally steady. I've found that steady seeing makes a successful observation of the Horsehead more likely.

Dave Mitsky

RE: Who Among Us Has Observed the Horsehead Nebula?

Anny20 — Mon, 08 Dec 2003 00:54:29 GMT

ive tried but can never seem to find it, it doesnt help that i live in a light polluted area.

RE: Who Among Us Has Observed the Horsehead Nebula?

Bill Weir — Sun, 07 Dec 2003 22:42:39 GMT

Last spring using a friends 16'' f5 truss dob with a 31'' Nagler and OIII filter we were pretty sure we could notice a darkened area jutting out into the lighter area, but a distinct shape was difficult to determine. Two weeks ago while looking around that same area of the sky with my 6'' skyquest at NGC2024, sigma orionis, struve 761 I thought I'd try for it because it is within the theoreical limit of my scope. With my 22lanthanum superwide and ultrablock filter I could notice the deliniation between dark and light areas but couldn't notice the dark juting out of the head. Sigh one day maybe I'll get a H-beta filter