Barnard's Loop Observers Analysis

[nebulaeman]

Thanks Kitwo:  102mm f/6 binoscope with some wide field eyepieces should make short work of Barnard's Loop!  Also, your f/6 should be able to handle enough high powered eyepieces to show most of the range of bright and dark nebulae in the region.  The Herbig-Haro might take some larger optics, but the beauty of a dark sky is that it will allow observation of just about everything.  Keep on looking in the dark!  Thank You!  nebulaeman

[scarp15]

I had been mindful concerning your book quite some time ago, so it is good to learn that it is now in print. This could provide new incentives, planning for on-going dark sky ventures, when weather and time permit, cheers.  

[nebulaeman]

Thanks scarp 15:  Yes, this has been a topic few have tried to dig deep.  However, in a dark sky the rewards are quite high!  I not only cover the well known Barnard material (which is a small part of the story), but I also try to help observers in seeing many other objects from Lynds, Sandqvist and Bernes to name only a few.  Many of these objects that are less known are actually easier than many of the Dark Nebulae objects most have heard of.  Barnard 33 is one of the most famous Dark Nebula, but is also one of the most difficult and I think this has led to the misunderstanding that Dark Nebulae are "difficult."  I introduce the reader to many Dark Nebulae such as Lynds Dark Nebulae ID#141 (a second internal list within the Lynds Catalog that is where Dr. Lynds connected multiple entries from her catalog into groups she felt were gravitationally connected) and due to their size they are easily visible to the Naked Eye in a dark sky.  The standard listing of Lynds DN 141 is found in Ophiuchus, but the Lynds DN ID#141 is found in southern Hercules and it is amazing that Barnard missed this clearly Naked Eye object.  In my book I discuss many of these little known Dark Nebulae that are visible to the Naked Eye if you have a dark sky.  

[Klitwo]

One of my all-time favorite (and rarely discussed) dark nebulae is Barnard 37 in Monoceros.  Always enjoyed observing it....easy to find lying North of Betelgeuse in the Monoceros Milky Way.  A must-observe dark nebulae for any dark nebulae observer.....

Klitwo

[nebulaeman]

Yes Klitwo:  Barnard 37 is in a wonderful region full of multiple Bright and Dark Nebulae!  It has the classic NGCs and ICs, but also both Lynds Bright and Dark Nebulae as well as objects from Dorschner Gurtler and Van den Bergh objects as well.  Of course, all of the catalogs after Barnard mentioned above were based off of the POSS.  However, of interest is the Dorschner Gurtler was out of East Germany, which those older among us would remember that this was in a much less friendly time (science can accomplish good work even in difficult times)!

[jetstream]

On 30/10/2018 at 16:49, GavStar said:

Unfortunately I’m not good at sketching but my phone photos give a good impression of the view through the night vision monoculars. 

Here are two taken at the sqm 21 garden earlier this month..

 

An update on observing Barnards Loop tonight- the 200mm f3.8 newt with the 30ES 82/Hb followed the object from M78 down to Saif with ease under 21.6 skies with good transparency.Temp -28c. The bright portion near M78 was visible with no filter.

[GavStar]

Great stuff Gerry! Although seeing the -28c temp makes me shiver!! ?

I had an even better session on Barnard’s Loop a few nights ago from the Isle of Wight (sqm 21.0) compared with my first observation. Transparency seemed better than when I saw it in October. And I noticed some extra stuff such as the rosette and the cone regions joining up with large nebulosity.

I note on CN recently a person mentioned seeing Barnard’s Loop naked eye through just an h beta filter - have you tried this?

Also I got the left hand side (with some curving to the bottom right) of the Eridanus Loop - have you tried for this? Certainly it was a fair bit fainter than Barnard’s.

Finally I got hints of the spaghetti supernova (Simeis 147) the other evening. However I was only viewing at 1x through my NV monoculars so it was a bit small. I need to get something bigger and fast on this (probably my Epsilon 130d which can run at f1.6).

Happy New Year!

[jetstream]

7 hours ago, GavStar said:

I note on CN recently a person mentioned seeing Barnard’s Loop naked eye through just an h beta filter - have you tried this?

Also I got the left hand side (with some curving to the bottom right) of the Eridanus Loop - have you tried for this? Certainly it was a fair bit fainter than Barnard’s.

Thanks Gavin, it was a fun new years eve observing.

Fantastic that you are getting some good sessions in and yes I have tried the eye/filter technique a few years ago with no luck. I will try again, thanks for reminding me of this.

The Eridanus Loop...

well last year I thought I saw a shade near the rumored "brighter" section but before confirming I like to be able to repeatedly see something. My weather this year consisted of rain, clouds, snow since Sept with very few chances to observe. For me, on this faint stuff I need many many sessions to get the object sometimes... this is proving to be a difficult object. I use Vogels map as a guide and if the skies are good I'm back at it again lol!

I have a question- near M78 while observing the Loop with no filter I thought I saw this object wider than when using the Hb - with NV how wide would you say the widest portion is near here? I'm wondering if there is a bit of OIII in the area or some other emission I'm picking up.  I picked up the very slightist hint of structure in parts of the Loop last night as well.

BTW the Pleiades Bubble was stunning, mesmerizing me as I sat by the ice. This object is a superb, dazzling gift of the sky.

[GavStar]

1 hour ago, jetstream said:

 

I have a question- near M78 while observing the Loop with no filter I thought I saw this object wider than when using the Hb - with NV how wide would you say the widest portion is near here? I'm wondering if there is a bit of OIII in the area or some other emission I'm picking up.  I picked up the very slightist hint of structure in parts of the Loop last night as well.

BTW the Pleiades Bubble was stunning, mesmerizing me as I sat by the ice. This object is a superb, dazzling gift of the sky.

Gerry, I’ve only observed Barnard’s Loop at 1x and never through a scope (yet!). The visual views are basically identical to my phone photo so if you see it wider than the photo then you are seeing non h alpha stuff I think.

I thought I would add that the ‘spoke’ of the loop going off to Betelgeuse is also lovely to see visually but again a fair bit fainter than the top bit of the ‘proper’ loop.

[David Levi]

I had a go at observing Barnard's Loop last night from a dark sky site in the Brecon Beacons. I was using my 100mm Takahashi refractor with TeleVue Panoptic 24mm eyepiece (giving an approximate 2° field of view) and Lumicon Hb filter.  I couldn't detect any change in contrast around the area that Barnard's Loop is located. I tried with and without the filter and even held the filter up to my eye as suggested on another recent post but could not detect the nebula.

I imagine that my failure to see the nebula is down to sky conditions and/or filter. I mention the filter because my second hand Lumicon filter says on it that its transmittance is 90.9% whereas I see that Astronomik state a near 100% transmittance of the Hb line. Do these figures suggest that the Astronomik filter would be better for the job of detecting this nebula?

[PeterW]

I wouldn’t worry about a few percent, darker skies or better transparency, not all dark nights are created equal. Keep trying, you’ll get there.

 

Peter

[jetstream]

5 hours ago, David Levi said:

I had a go at observing Barnard's Loop last night from a dark sky site in the Brecon Beacons. I was using my 100mm Takahashi refractor with TeleVue Panoptic 24mm eyepiece (giving an approximate 2° field of view) and Lumicon Hb filter.  I couldn't detect any change in contrast around the area that Barnard's Loop is located. I tried with and without the filter and even held the filter up to my eye as suggested on another recent post but could not detect the nebula.

I imagine that my failure to see the nebula is down to sky conditions and/or filter. I mention the filter because my second hand Lumicon filter says on it that its transmittance is 90.9% whereas I see that Astronomik state a near 100% transmittance of the Hb line. Do these figures suggest that the Astronomik filter would be better for the job of detecting this nebula?

What f ratio is your scope?

 In my experience there might be 2 things holding you back on Barnards Loop- exit pupil and TFOV.  For these very large objects more eye illumination- 4.5mm minimum and preferably 5mm-6mm. I use 5.6mm in the frac.

The 24 Pan, while VG gives a bit narrow TFOV even in your 100mm IMHO. Can you try a 34mm ES 68 or 40mm or similar? If the exit pupil was larger with you 24 Pan you would catch the edge of the Loop- just as a shade edge. Even a 32mm TV plossl might give enough illumination to help.

You will see the Loop David, keep at it- I like hearing of these attempts and successes.

Gerry

[David Levi]

Thanks for the advice Gerry @jetstream, I appreciate it. The telescope is a 7.4 f ratio. I was afraid that my current longest focal length eyepiece , the 24mm Panoptic, wouldn't give me a wide enough field of view. I've been keeping my eye open for some good quality second hand longer focal length eyepieces but the ones I would like (Nagler 31mm and Panoptic 41mm) haven't come up for sale yet.

[David Levi]

Just to add another technique in the attempt to observe Barnard's Loop. I was out again last night at my usual dark sky site in the Brecon Beacons when towards the end of my session and with thoughts turning to this nebula, it suddenly occurred to me, with my limited wide field view resources, that I could put the Hb filter in front of my finderscope. I was pleased to discover that the 1.25" filter fits perfectly into the recess at the front of the 6x30 Takahashi finderscope. I'm going to try this again the next time I'm under dark skies because there was a suggestion of some contrast changes at the location of Barnard's Loop. I need to improve my mental map of Barnard's Loop and study pictures of it that are hopefully more accurate than the hard line boundary drawn in the Interstellarum atlas.

[jetstream]

Very good idea David-actually I might unpack my Tak finderscope and put my Astronomik 1.25" filte (excellent) on it to try as well. In my limited experience this object can be scope sensitive. BTW the diminutive Heritage 130 shows it well. I just can't make the filter held up to the eye work on this for some reason.

[David Levi]

Well Gerry @jetstream, I for one would be very interested to hear about the results of trying the Tak finderscope with the Astronomik Hb filter. 

[jetstream]

I have no predictions- this can be a really fickle object. For me I always shoot for the section adjacent to M78 first as this seems to be the brightest section(to my eyes).

[PeterW]

CWallets will be happy getting the heritage.... sometime you need a BIG field of view! Good luck 

peter

[David Levi]

1 hour ago, jetstream said:

I always shoot for the section adjacent to M78

That's the area that I have been concentrating on following your and others suggestion.

[jetstream]

So these Tak finder are all the same ie 30mmx6 power? which should give an exit pupil of a VG 5mm for use with the HB, 6mm would be better but 5 will work.

[David Levi]

I was out in the Brecon Beacons last night with Barnard's Loop being my first priority target. Armed with two new second hand long focal length eyepieces and an Astronomik 2" H-beta filter to fit them, I was hopeful that I would be able to see this elusive emission nebula. The eyepieces in question are the TeleVue Nagler 31mm and the Vixen LVW 42mm. In my 100mm refractor these give respectively a TFoV of 3.2° and 3.6°, an exit pupil of 4.2mm and 5.7mm and magnifications of 24x and 18x.

Using the Vixen LVW 42mm eyepiece and moving up from the star Alnitak in Orion's belt to M78 I looked to the north and east (right in my scope view using a star diagonal). I could just make out some cloudiness arcing around M78. As my eyes became more accustomed to the view the nebulosity became more obvious and more extensive. I could move further away from this location up and down Barnard's Loop almost tracing out it's whole length. It was not as prominent further away from the initial search location and often I lost the track of it and had to go back to the densest part to start again. I spent at least half an hour doing this, changing between the two eyepieces before concluding that the 42mm Vixen gave the clearest views. The wider field meant that it was easier to see the nebula in context against a larger area of darkness.

[scarp15]

That is excellent David and you were clearly in the right location at the right time, with a night of good transparency. I quite understand how the 42mm vixen and 5.7mm exit pupil had presented the clearer view. Hope you get to explore this region again, if not for now then next season and perhaps even contemplate the southern arc away from Rigel.