Barnard's Loop - the whole semicircle in binoculars

[Uwe Glahn]

Some days ago I spend two nights to study Barnard's Loop. The question was - how long is the arc observable. I used a Nikon 8x30 EII binocular with two H? filters, which gave a single field of around 8.8?, which is around the half of the size of the whole Loop. Observing conditions were average, NELM around 6.5mag. The Loop was an easy target for the naked eye with the H? filters.

To my surprise, the loop was easily visible as a semicircle. Of course with the brightest part NE of M 78. Especially the straight arc part between Saiph and Rigel was visible without any problems. The fainter part was the extension to the NW starting from the brightest part, moving under ome Ori to 38 Ori. Saiph was open and limited by an arc to the NW, difficult to distinguish between the contrast phenomena from the star itself and the real arc.

M 42/43 were of course very bright to the H?. The reflection parts around NGC 1977 and NGC 2024 were also visible easily. The biggest challenge was the thin lane of IC 434. Bright in larger aperture, the lane was only barely visible, because of the small size unfavorable scale of only 8x magnification. Interestingly the star group down to the 6.2mag bright HD 37744 gave a nebulous character, but the "false" IC 434. The emission nebula was only visible as a 1' long, extremely faint line, interestingly with a harder edge to the western side.

What are your experiences with the Loop? How long could you observe the arc and what instrument do you use?

sketch:
Sh2-276.jpg
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larger resolution

[oliva]

Hi Uwe,

Looking back through my observations from 2016 I found that the arc is visible till Saiph:

"[...] I tried to observe [Barnard?s Loop] with my 10x50 binoculars together with two 2? filters. On the left front lens an Astronomic UHC and on the right a Lumicon H-Beta filter were placed. The brightest part of Barnard's Loop northeast of M78 can be seen quite well. Disturbing stars can be excluded because the nebula is located between two star chains and there aren?t any bright stars within the arc segment. The segment can be followed up to the level of the belt stars and further till Saiph. Overall, the impression is similar to that with the naked eye."

By the way: Under very transparent and dark sky I saw the arc between Saiph and Rigel too using an OIII and H-Beta Filter with the naked eye but finally I considered that observation to be some kind of suspicious after all.

Using my 14 inch Newton with an H-Beta Filter Barnard's Loop appears quite well and even the nebulae between Saiph and Rigel appears as kind of structured nebula. The full arc can be seen following the circle. Even though the nebulae between M42 and the arc can be spot.

Oliver

[Norman]

just great mate.

[Uwe Glahn]

Looks that the topic is of no interest in any. So thanks for your response my friends.

Oliver, I also tried the part between Saiph and Rigel with the naked eye but definitely failed. But who know, perhaps it is possible under better transparency? When I calculate right, you got a field of around 1.5? with your 14-inch? Great catch to see the faint parts through that "narrow" field. Thanks for your try and your contribution.

[j.gardavsky]

Hello Uwe,

and once again thank you for the amazing sketch!

On the Barnard's Loop, I have 17 observing entries in my logbook, the best one is of March 7th, 2016:
Arc followed from 51, 56 Ori at north, down to 55 Ori at south, where the Loop begins to bend. This makes about 8deg in declination.
More have not been visible.
Binoculars: 7x50 CZJ Jenoptems, no filters
Place: Silvaplana, Swiss Alps

Your sketch is an inspiration for me to return to the Barnard's Loop once again, and with the 15x85 binoculars.

Clear skies,
JG

[Norman]

Hi Uwe,
i would rather guess that everybody is still paralized infront of his screen ;-) "greasy mode off" ;-)

Astonishing, that even with "only" 6m5 NELM the loop is that easy for you. The exit pupil of under 4 mm is interesting too. I tried naked eye with one Hbeta only from my balcony (similar NELM) but with a bit of straylight of course. I haven?t seen anything. But i have to admit - i didn?t know where to look exactly, especially regarding to the brightest part that maybe would have been within reach.

The detail in your drawing with 8x30 under that skies is almost surprising (IC 434) - very cool.

Alone the stars... i would need one whole clear week alone to sketch them...

CS
Norman

[Don Pensack]

Some days ago I spend two nights to study Barnard's Loop. The question was - how long is the arc observable. I used a Nikon 8x30 EII binocular with two H? filters, which gave a single field of around 8.8?, which is around the half of the size of the whole Loop. Observing conditions were average, NELM around 6.5mag. The Loop was an easy target for the naked eye with the H? filters.

To my surprise, the loop was easily visible as a semicircle. Of course with the brightest part NE of M 78. Especially the straight arc part between Saiph and Rigel was visible without any problems. The fainter part was the extension to the NW starting from the brightest part, moving under ome Ori to 38 Ori. Saiph was open and limited by an arc to the NW, difficult to distinguish between the contrast phenomena from the star itself and the real arc.

M 42/43 were of course very bright to the H?. The reflection parts around NGC 1977 and NGC 2024 were also visible easily. The biggest challenge was the thin lane of IC 434. Bright in larger aperture, the lane was only barely visible, because of the small size unfavorable scale of only 8x magnification. Interestingly the star group down to the 6.2mag bright HD 37744 gave a nebulous character, but the "false" IC 434. The emission nebula was only visible as a 1' long, extremely faint line, interestingly with a harder edge to the western side.

What are your experiences with the Loop? How long could you observe the arc and what instrument do you use?

sketch:
Sh2-276.jpg
home
larger resolution

I have observed the full length of the arc with an H-Beta filter mounted on a short extension tube pressed up to my eye socket to block all peripheral light.
This is at a high altitude site (2250m) and a sky darkness of ~21.5mpsas.
I could also see a glow around Lambda Orionis.
As you note, the Loop is a full semi-circle from Orion's upper chest area around to nearly Rigel.
[Using the same technique and a high-end O-III filter, I have see the Veil nebula with the naked eye in the same way.]
So, an aperture of about 5mm at 1 power.

[Uwe Glahn]

Jiri, Norman and Don,

thanks for your replies.

@Jiri
Interesting, that you saw the Loop without any filter. Yesterday I spoke with Haj?, who saw the Loop also without any filter with the naked eye but under perfect transparency under a High Alpine sky.

@Norman
You have to use two H? filters and prevent all possible straylight. The balcony, even if it is dark is not the best place to do such faint objects. My sky, especially to the south were perhaps a little bit better than 6m5. Mathias Sawo and Oliver Stein also had similar experiences (and sketches) under similar skies with naked eye.

@Don
Thanks for the confirmation of the visibility of the Lambda Orionis Ring. It was also popping in and out of view but way more difficult as the brightest parts of the Loop. I catches the Ring in the past also with my Nikon 8x30 and two H? filter.
To see the Veil is astonishing. Always thought, that the arcs are two small for the naked eyes. But I will give it a try.

[Norman]

Hi Uwe,
of course it was a bit optimistic to try it from the balcony ;-)
But as you know - you never can tell :-) I felt encouraged by very positive results at B33 from the balcony (12", Hbeta) - IC 434 has also been visible in my 72 mm (with Hbeta as well) quite easy in one night.
Maye i will cover the nearby lantern in future, we will see whats possible then ;-)
I will check the loop next time in the alps.

CS
Norman

[Bertrand Laville]

Hi Folks,

Here is how I saw Barnard's Loop, two years ago, with a L100 x 20/UHC.
The field of view is 5?, and the UHC filter is an old Lumicon with which the H alpha is not stopped.
Sky was average, NELM 6.6v and SQML 21.63
Detailed report here: http://www.deepsky-drawings.com/sh2-276/dsdlang/fr

Clear sky
Bertrand

Sh2-276-LC100-BL-2019-01-03-1.jpg

[j.gardavsky]

Jiri, Norman and Don,

thanks for your replies.

@Jiri
Interesting, that you saw the Loop without any filter. Yesterday I spoke with Haj?, who saw the Loop also without any filter with the naked eye but under perfect transparency under a High Alpine sky.
...

Hello Uwe,

the Jenoptems 7x50 have too small EPs barrells to mount the 1.25" filters, and this has been the reason to finally part with these binos.
Most of my observations of the Barnard's Loop in the past have been with the binoculars without any filters at all.

I will certainly return to the Barnard's Loop and to some other objects in Orion with the 15x85 binoculars plus filters.

Regarding the Lambda Orionis Nebula Sh2-264, I have frequently seen it in full extent through the binoculars 7x42 up to 25x100, and a few times have seen its brightest part bordering with B30/B31 with the unaided eyes: from the Lillinghof Airfield and even from our backyard.
What is still left is to isolate the forgotten Gaze-Shajn 63 condensation in the Sh2-264.

Otherwise, the most difficult binocular Sharpless in this area has been the Sh2-278, pointed to by the south-west arc of the Barnard's Loop. I have just 2 entries in my logbook. Through the 6" refractor, it is not a problem, showing nicely its form.

Clear skies,
JG

[kisspeter]

Hi Uwe,

I can't contribute too much to the Barnard's Loop. I never really tried it seriously. It is very common that fog covers basically the whole of Hungary in winter for weeks. (We had the same this winter - and nobody saw the Jupiter-Saturn conjunction from the country..)

I had a sneak peek in the big Fujinon binoculars at Hakos, Namibia in 2016. With 2 H-beta filters held in front of the eyepieces the Barnard's Loop was basically visible at first sight as I remember (no sketch or notes).

There are so many beautiful objects on the winter sky I would like to draw.