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Nebula for H-Beta

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#1 Jeff Morgan

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Posted 07 February 2020 - 03:25 PM

In the current IC 443 thread, there was a sidetrack into the usefulness of the H-Beta filter. It seemed more appropriate as a separate thread in its own right, so here it is.

 

Some of us old-timers may remember Lumicon advertising referring to H-Beta filter as "the HorseHead filter". And probably a lot of us bought it based on that alone. I know I was one of them!

 

David Knisely published a list of other nebula where the H-Beta filter works. I suppose "works" is defined by Expectations, going down the list I had some nice successes and some so/so results where O-III or UHC was more revealing. In fact, I sold my H-Beta (and the others) to consolidate on the DGM NPB filter. But who knows, I may find reason to try it again ;)

 

What observations have you made with the H-Beta, and what were your impressions? Which objects in the "Knisely Catalog" are the H-Beta Stars? To get the party started, my logged H-Beta specific observations:

 

  • Sh 2-84, Sagitta, Jun 8, 2011, R12.5, Home: Perhaps transparency not as good as I thought. Barely detected with the UHC filter, seemed to react slightly better to H-Beta.‚Äč
  • Sh 2-9, Scorpius, Jun 22, 2011, R12.5, Mingus: Responded to H-Beta filter. Easiest to detect when moving scope E-W. N and S edges not distinct.
  • Sh 2-115, Cygnus, Jul 20, 2011, Star12, Home: Relatively easy to see w/out filter. The nebula will respond to H-Beta and O-III but was best with the UHC.
  • Sh 2-125, Cygnus, Jun 4, 2011, R12.5, Home: Cocoon Nebula - Struggling against the approaching twilight and distant porch light. Think I got it for the second time, only other time was in a 4" Vixen f/10 achromat with binoviewer. Jumped from 81 Cyg south to sharply defined B168. Followed the dark nebula east to the spot. Amorphous mass on the edge of visibility, easiest feature to see were dark rifts which helped define edges. Responded slightly to H-Beta filter. Primarily used 31 Nagler. Need to familiarize myself better with the field before trying more magnification. Cluster Cr470 not evident.
  • Sh 2-88, Vulpecula, Jun 20, 2011, Star12, Home: Not easily seen. Responds somewhat to O-III, best with UHC. No response to H-Beta. Indefinite edges, best view with 24 Brandon (42x) or 22 Panoptic (46x).
  • IC 1318, Cygnus, Jun 9, 2011, Star12, Home: I did not see the double star but the Gamma Cyg region is incredible in the 48 Brandon (21x). A rich star field with hints of nebulosity. Adding a UHC filter makes a dramatic difference. (Hydrogen-Beta filter not effective.) The immediate impression is not that the nebulosity pops, but that prominent dark lanes are created running E-W and N of Gamma. As the eye acclimates the nebulosity becomes easier to trace, especially W and N of Gamma. Several weak open clusters embedded/associated with the area. I could spend hours on this star field. Identified IC 1318 a, c, d, and e.
  • Sh 2-105, Cygnus, Jun 11, 2011, Star12, Home: NGC 6888. Reacts well to UHC filter, negative to H-Beta and O-III. Held steadily in 24 Brandon no filters (42x). Best view in 12 Brandon and 13 Ethos, SW portion of nebula most visible. Not sharply defined.

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#2 brentknight

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Posted 07 February 2020 - 11:50 PM

I just picked up the TV H-Beta - yep, for the Horsehead.  But I also wanted to try it out on other objects and with binoculars.  Now all I need is some clear, dark skies...



#3 Redbetter

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Posted 08 February 2020 - 04:28 AM

Strange that you have NGC 6888 as negative for both OIII and H-Beta.  This one is known to respond well to OIII since it has a bright OIII shell ejected by the a Wolf-Rayet star.  Knisely shows it as strongest in that, 5 vs. 4 for UHC.  When I most recently logged it I was using an NPB and didn't have an OIII since my old OIII was somewhat "rusted".  I don't believe I tried H-Beta.  I am sure I have checked it some since with a newer OIII. 

 

I have only observed Sh2-84 in the 20" with 16T5 and Farpoint UHC filter.  "Surprisingly large and bright patch of emission nebulae between 7 and 8 mag stars.  Extends in long arc.  Thick, extends to east curling past dimmer star."  I was expecting something smaller.  Could probably target with 20T5 and H-Beta for comparison since I lack a functional 1.25" H-Beta.

 

Similarly I didn't check Sh2-88 with H-Beta.  It was near the end of a session and the notes were sparse:  "Somewhat easier to see with an Ultrablock and 31T5.  Had to pan to really take it in, much is AV."  Not sure if I tried H-Beta.  I had used the H-Beta earlier on Sh2-86, which helped better define the dark lanes than the Ultrablock did--had the same impression with the OIII which is interesting.

 

I don't have my observations digitally recorded by filter type, and although I record which filters were used to some extent, it is primarily the one that I used most for the target, rather than saying what did not work as well.  While nebula observing is not a primary activity for me, I have gone through most of Knisely's H-Beta list in the past. 

  • Horsehead (IC 434/B33) frequently observed with H-Beta.   On the most transparent nights I can detect it without a filter in dark sky, but it does best with H-Beta.  I have used 5" Mak, 8" SCT, and 20" Dob.  Have detected the notch with smaller.
  • North America Nebula, NGC 7000.  While not primarily an H-Beta target, it responds well to it.  Had good contrast at my brighter low elevation Bortle 3 site at 21.1 MPSAS.  I prefer a UHC or NPB for this one in most instances.
  • Pelican Nebula (IC 5067/70), much like the above.
  • IC 5076 small diffuse nebula around 5th mag star.  H-Beta in the 20" with 31T5 revealed about 7+ arc minutes of nebulosity (~1/8th of field diameter.)
  • IC 5146/B168 Cocoon Nebula, 20" w/ 31T5.  Well seen, bright emission nebula roughly 1/6 field around 9 arc minutes, traced the dark nebula filaments out for several degrees.  Compared with NPB, H-Beta was better, particular tracing the dark nebula.
  • IC 1318A/B/C/D/E have traced this area out a number of times with the H-Beta and other bits of nebulosity scattered about. 
  • IC 405 Flaming Star Nebula,  over halfway across 31T5 field in the 20".  Seen as a "lick of flame, long and extended, brighter than expected."
  • Barnard's Loop (Sh2-276) -- While I have used a DGM NPB on this one and had good results at times, I prefer to use the H-Beta.   I have used various apertures to trace this out in dark skies with H-Beta, from the stretch in the north, following the arc as it brightens and widens, and dims again, all the way through Orion's feet.   I have seen it with 2.3x binocs (single eye filter), 60ED, 80 f/5, 110ED, 20" and probably others.  One time recently on a night of excellent transparency I was able to detect it naked eye arcing around and through the feet, repeatedly, but extremely vaguely.  The wide field of the 60ED and 80 f/5 adapted to 2" don't require as much panning to take it all in. 
  • California Nebula (NGC 1499) --  this one is bright with an H-Beta.  Easy to see with a single eye looking through 2.3x binoc with filter.  It is good in any aperture, really liked the framing in 110ED f/7, but have used 60, 80's, etc.  The 20" is useful for panning around to see detail. 
  • Sh2-157a, a small section in Sh2-157.  This little section responds best to H-Beta (I compared to DGM NPB and  a UHC), but the broader Sh2-157 nebula is barely visible with the H-Beta while is better seen with the NPB and UHC.
  • Lamba Orionis "Angelfish Nebula", Sh2-264.  While I first viewed this in the 20" with the NPB,  I was only sure about the inner 2 degrees of nebulosity this way (panning about.)  I have barely detected it with no filters using the 2.3x binocs in frigid transparent skies.  During a later session I could see it in the binocs with an H-Beta over one side and UHC style Ultrablock over the other side.  Then I viewed it with the 80 f/5 in 2" using a 41 Pan with H-Beta for a very wide field (6.6 degrees) but I still had to pan around to see the edges.   Finally, on the same night that I could see Barnard's Loop naked eye, I could also see this one as a large roundish haze.   
  • Propeller Nebula, Simeis 57 (DWB 111, 119 with 118 forming background).  Seen decently w/H-Beta in 20" w/ 31T5.  Saw the three props on the background haze.

That is a mix of older and newer observations that came to mind.  I haven't gone looking for other observations I made that are specifically H-Beta. 


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#4 j.gardavsky

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Posted 08 February 2020 - 03:05 PM

Sh2-84 in Sagitta: A possible Wolf-Rayet nebula associated(?) with WR 128. Arc through the OIII and H-Beta, otherwise faint through the UHC on my 6" refractor.

 

Sh2-88 (LBN 137, 138, 139) in Vulpecula: Just a faint fuzzy through the 15x85 binoculars with the H-Beta filters.

There are a few more such faint Sharpless nebulae north off Sh2-88 for the H-Beta filters.

 

Best,

JG



#5 brentknight

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Posted 08 February 2020 - 03:10 PM

Just curious...how do you use 2" filters in larger binoculars?

#6 j.gardavsky

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Posted 08 February 2020 - 03:38 PM

Just curious...how do you use 2" filters in larger binoculars?

I screw the 1.25" filters nto the filter threads on the binocular eyepieces, or fasten the filters with added rubber eyeguards,

 

gallery_316833_12015_17090.jpg

 

There is a saying, get it screwed,

JG


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#7 brentknight

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Posted 08 February 2020 - 06:18 PM

I see...I've always stuck them on the front.
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