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sanath
September 25th, 2015, 07:30 PM
Hello DSF,
i couldn't find much about observing Merope nebula, i have observed this from a bortle-3 sky in 2013 with a 17.5" and a 30mm eyepiece, the nebula was just visible, but during a recent visit to a NELM +5.5mag location, i was using an 8" f/6 scope with a 30mm wide angle eyepiece and i could sense some nebulosity around the brighter stars of M45, there was no dew problem and the eyepiece was kept in a box so i could safely eliminate that to be the culprit, also i happen to see a strong cutoff line next to a star which i later checked in software and turned out to be merope, i didn't make a log of it unfortunately, my question to all the experts here is, is it possible to see M45 nebulosity around the stars so easily with a small aperture like an 8"? or was it something else.

Howard B
September 26th, 2015, 06:19 AM
Hi Sanath,

Seeing the Merope Nebula and other nebulosity within the Pleiades with an 8 inch scope is well within the capabilities of this size - and smaller - instruments. I've had excellent views through my own 8 inch scopes and actually prefer them over my larger instruments because I can see the entire cluster and associated nebulosities in context. So I have no doubt you saw it too in your scope.

sanath
September 26th, 2015, 12:26 PM
Hi Howard,
Thanks for replying, i had seen this a few times and was never sure about it, next time i shall make a log with a sketch of the same and add to this thread.

Howard B
September 27th, 2015, 05:50 AM
Yes, making a sketch will not only record what you see but will also insure you see as much as possible - I look forward to seeing your sketch!

akarsh
September 27th, 2015, 11:43 PM
Hi Sanath

The best indicator is that even if the star is in the center of your FOV, the glow around the star is non-uniform. Typically, if you put the star in the center of the FOV and your dob is well-collimated, any optical aberrations should be circularly symmetric. The Merope nebula is not. This is one way to check that you are not seeing glare.

Especially, if you saw a sharp "cut-off" like you mention, it is very likely that you saw the nebula. And like Howard says, a sketch is very helpful to both log and check your observation, so that might be nice. And yes, I do think that it should be possible with an 8".

Nice to see you posting on DSF :-)

Clear Skies

Regards
Akarsh

reiner
October 4th, 2015, 09:59 AM
Hi Akarsh,

you are having the common problem of seeing Merope's Nebula for the first time. For me, this was a challenge as well, as there may be problems with moisture in the air, dew, and the contrast of the bright Plejades stars.

Merope's Nebula has the advantage of being offset to Merope, so look specifically for that. Once you've spotted it the first time, the next times will be much easier. If I remember it correctly, I could see the nebula onve even with my 15x70 binoculars.

Also look for the tiny nebula directly at Merope, Barnard's Nebula, which is an entirely different story (http://www.deepskyforum.com/showthread.php?449-Object-of-the-Week-September-22-2013-Merope-s-and-Barnard-s-Nebula)

akarsh
October 8th, 2015, 05:15 PM
Dear Reiner

I was looking through the old OOTWs yesterday so I could pick up objects for my observing sessions (planned maybe for the weekend or some time during next week depending on sky conditions), and I came across your OOTW on Barnard's Nebula. It seems like it might be very very difficult with an 18", but maybe I'll have steady skies, who knows. What is the focal length of your telescope; you said you used a 6mm eyepiece, so I'm trying to estimate the magnification that you used.

Viele Grüße
Clear Skies
Akarsh

Paul Alsing
October 9th, 2015, 06:37 PM
Dear Reiner

I was looking through the old OOTWs yesterday so I could pick up objects for my observing sessions (planned maybe for the weekend or some time during next week depending on sky conditions), and I came across your OOTW on Barnard's Nebula. It seems like it might be very very difficult with an 18", but maybe I'll have steady skies, who knows. What is the focal length of your telescope; you said you used a 6mm eyepiece, so I'm trying to estimate the magnification that you used.

Viele Grüße
Clear Skies
Akarsh

Hi Akarsh

Barnard’s Merope Nebula, IC 349, is a lot easier to see if you can fit an occulting bar into an eyepiece. This way you can block much of the light of Merope itself.

http://www.eagleseye.me.uk/Resources/OccultingBar.pdf

https://www.safaribooksonline.com/library/view/astronomy-hacks/0596100604/ch04s09.html

You should use an eyepiece that does not come to focus inside the eyepiece or you won't be able to get a sharp edge.

Howard B
October 10th, 2015, 03:27 AM
Another way to see IC 349 is to use a narrow field of view eyepiece and place Merope just outside the fov. I use a Plossel eyepiece for the times I need to see something faint near a bright star.

akarsh
October 10th, 2015, 04:05 AM
Howard, Paul:

The article that Paul linked has a point, that eyepieces perform best near the center, so it's preferable to have an occulting bar. I'll probably just use black vinyl electrical tape. How does one locate the field stop of the eyepiece without dismantling it? I think I have a Plössl from Orion, similar to the one described in the second link that Paul shared, so it probably might be similar...

Regards
Akarsh