Night of the Nebulae

[davesellars]

After the previous night's exceptional transparency, I had my hopes raised it would be similar. It had been a mix of clouds during the day but by late afternoon it gave ways to nice breaks of very clean blue sky. Around 10pm I set up in a corner of the back garden with the 120ST on the Alt/Az which was much more suitable for the Cygnus region where the North America nebula (NaN) would be my primary target fort the evening. Large wafts of clouds were still present but it was forecast to improve considerably around midnight and so I went back in for power nap.

It cleared quite a bit in the end by 00:30 although some mid/low level clouds were still present. The transparency was again excellent easily seeing directly to mag 5 without any difficulty.

I have previously given the NaN numerous attempts before without success, although I'd only attempted to use a Hbeta filter on it or no filter, half expecting a large cloud of nebulosity to be visible. It turns out, this is far from the case (especially in these skies anyway...) and that I'd been using the wrong filter.

With the 32mm Baader Plossl I centred my position between Xi Cyg and 57 Cyg giving me theoretically an entire view of the nebula in the eyepiece FOV. First without any filter for comparison of what extra was going to be added that was not MW "background", fine stars predominate with numerous bright stars - it's really a fantastic open star cluster to view in its own right. Then placing in the Astronomik OIII, the star cloud diminshed and replaced with a nebulous activity. Immediately, I could distinguish the Gulf of Mexico shape that was sharply defined - indeed the lower lobe was relatively bright. Less sharply defined was the 57 Cyg side as the nebula faded in from blackness. I swapped out the Astronomik OIII for the Baader OIII which has a slightly narrower band-pass. This was almost too much for the remainder of the nebula apart from the brighter regions however the Gulf was very sharply defined with this. Swapping out for the Astronomik UHC filter, this was a different view again. Less defined but seemingly more of the main area of the nebula seemed to be apparent - Perhaps a touch of darker region splitting up the nebula into component parts however not defined well. Two very different views really and I could not say that the OIII nor the UHC provided a "better" view.

I repeated with the 18mm BCO in place of the 32mm Plossl and found that this gave a really nice result with the Astronomik OIII around the gulf region now showing some distinct bright patches particularly on the western side. For the most part the remainder of the nebula diminished.

Now I know what to look for, I shall look forward to pointing the extra light gathering power of the 12" dob on this target!

I moved over slightly to the Pelican nebula however I could not see anything here. I think this may be more a target for the 12" dob.

Moving to the Veil nebula with the 32mm Plossl initially with the Baader OIII, The Western Veil was very bright and there also seemed to be a hint of NGC 6974 (the middle bit). Switching to the BCO 18mm defined much more and up to the Eastern Veil, this was quite spectacular almost filling the view with an array of knots and twirls I never tire of viewing the Veil!

With the 18mm BCO still in place I went to Pleiades. As it's a reflection nebula, no filter... The view with the BCO was quite something - The brightness of the stars almost making any nebulous viewing very difficult however it seemed obvious that a few nebulous "brighter" non distinct areas seemed to be apparent.

Next up was M33. With the 18mm BCO this was in your face obvious large area almost filling the frame of 4 brighter stars. The central core was distinctly brighter but I could not make out any distinct arms. With the 10mm BCO a variability of brightness was easy to see in the face of the galaxy (still no arms) however the swirl of the core could definitely be seen.

I finished up with the wonderful Double Cluster and was about to move over to the Heart / Soul nebulae when large clouds came over covering the entire sky. It was already close to 2:30am so decided to call it a night. As I was packing away, typically the cloud appeared to move off! :p Still, it had been a successful and productive evening and very happy to finally bag the North America Nebula!

[John Baars]

Thanks for your nice report!
It demonstrates nicely the behavior of the used filters in combination with your instrument and the right exit-pupil. Your observations reminded me clearly of my own on a darker location three weeks ago. Well done. A pleasure to read!
I nominate your report for VROD!

[Unitron48]

Great reporting and session seeking out nebula in Cygnus, Dave! Certainly VROD worthy!

Dave

[Makuser]

Hi Dave. A superb observing report using the 120ST scope. You did a great job covering Cygnus and other targets. And as John said, your comparisons of the filters and the results obtained were very informative. Also, although not a narrow band filter, I have found that the lesser costly Wratten #82A (light blue with 73% transmission factor) will sometimes bring out more highlights and details in galaxies. Thanks for your well written report Dave and I also considerate it as VROD worthy.

[Bigzmey]

Great session and report Dave! Congrats on logging NaN.

It does pay to play with different filters on nebulae. Many OC have nebulosity associated with them to. Fiddling with filters and EPs at night gets old fast. So, I have invested in a filter wheel. Makes changing and comparing filters a breeze. The filters are also protected from the elements and accidental scratches, drops, etc. You leave one position empty and fill four positions with filters of your choice. I use it (with a set of planetary filters) for planets to, Mars in particular.

[davesellars]

Thanks guys!

Yes, I think the filter wheel is probably a good idea although my very tolerant Wife may disown me if I make any more astro-purchases. I'll have to look out for a cheap one used though!

My next "project" is the Heart & Soul nebulae. Placed really well later past midnight at the moment almost directly up. I'll have to have a look at the Pacman nebula again as well although I've observed this a long time when I was living in Oxford.

[John Baars]

Congratulations on the VROD!

[helicon]

:cool: Fantastic report Dave and a great utilization of filters to detect some difficult summer objects. Congratulations on a well-deserved VROD. I generally haven't used filters too much but clearly this is short-sighted on my part.

[davesellars]

Many thanks Michael!

The main problem with filters as mentioned by Andrey is they are indeed a pain to start putting in and out again, swapping around... even more so when the temperature plummets so I have a general avoidance in the winter months of using them... Not so bad in the summer though and concentrating on one object specifically.

[kt4hx]

Well done Dave. You observed some great objects and made excellent use of your filters to gain differing perspectives. I like your comparison of the Astronomik vs Baader O-III filters, then the Astronomik UHC. First off, since the Baader has a bandwidth of 10nm it covers only one of the two O-III lines, which of course is more restrictive. The Astronomik is slightly less aggressive with a 14nm bandwidth and passes both lines, which is the boost you noted.

Regarding the O-III vs UHC, I have done a similar comparison of the two on the Orion Nebula. The views are noticeably different of course, as you found with the NaN. Both views were intriguing and pleasing, but different. That can be the fun of playing with filters, you gain differing perspectives sometimes.

Being primarily a galaxy hunter, I took interest in your M33 descriptions. Its surface brightness is so low that while its not difficult to see, it can be difficult to pull out details. On nights of excellent transparency, you may wish to refer to the following link to see what details you can pull out of is very diaphanous disk. Again, well done and congrats on your VROD.

https://www.astronomy-mall.com/Adventur ... louds.html

[Makuser]

Hi @Bigzmey. Thanks for the tip on the filter wheel. When I got back into astronomy, I recalled my old photography days and the value of filters. So I ended up assembling a huge collection:

But then I found that I really only use 5 of them most of the time for lunar/planetary observing:

I thought about something to hold several filters at one time, but back then the only one I could find was a cheap bar type that went from side to side (like an old slide film projector). This didn't look very substantial and offered no protection for the filters and never thought about it again. I have now added the filter wheel (at a reasonable price) that you posted on this thread into our purchase cart and hope to get it soon. Thanks again for this information Andrey.

[davesellars]

Being primarily a galaxy hunter, I took interest in your M33 descriptions. Its surface brightness is so low that while its not difficult to see, it can be difficult to pull out details. On nights of excellent transparency, you may wish to refer to the following link to see what details you can pull out of is very diaphanous disk. Again, well done and congrats on your VROD.

https://www.astronomy-mall.com/Adventur ... louds.html

Alan, many thanks and also for the link - I'll going to make good note of this to use when next out with the 12" dob. Unfortunately, incredibly transparent and moon-less nights are a rare thing however it's awesome when you get one - the difference can be outstanding.

[Bigzmey]

Hi @Bigzmey. Thanks for the tip on the filter wheel. When I got back into astronomy, I recalled my old photography days and the value of filters. So I ended up assembling a huge collection:
my filters.JPG

But then I found that I really only use 5 of them most of the time for lunar/planetary observing:

favorite filters2.JPG

I thought about something to hold several filters at one time, but back then the only one I could find was a cheap bar type that went from side to side (like an old slide film projector). This didn't look very substantial and offered no protection for the filters and never thought about it again. I have now added the filter wheel (at a reasonable price) that you posted on this thread into our purchase cart and hope to get it soon. Thanks again for this information Andrey.

Nice filter collection Marshal! Filter wheel is a game changer for using filters. Makes swapping filters and comparing filters fast and fun. Switching EP (while using filters) is also fast. Here are my 150ST and C8 set up for filter use with filter wheels and little 80ED on top with EP turret.

[Unitron48]

Great reporting and session seeking out nebula in Cygnus, Dave! Certainly VROD worthy!

Dave

And congrats on your VROD recognition!

Dave

[terrynak]

Glad to see you finally observe the NAN and trying a variety of filters on it, Dave!

I saw the NAN first with a narrowband and then later with an OIII, also from Bortle 5 skies.

I bought a filter wheel over a decade ago which I never used - I'll need to dig it up and test it out...