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Seeing the Rosette visually


domstar

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Hi everyone,

I've been looking at the Rosette over the last couple of days of wonderful but cold conditions and I would like to ask for your help. I can see the cluster in the middle and I wondered about the surrounding Nebula. Is is possible to see through the eyepiece, and how difficult is it? I can see a sort of doughnut of emptiness around the cluster. Would that be it or is it just an area with fewer stars? I tried with a UHC filter but that didn't seem to help. I would love to hear about others' experiences with this and any pointers. Even a 'give up now' would be useful. I only have a 100mm frac and I know it isn't the ideal instrument for this sort of thing.

Thanks

Dominic

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I’ve tried for this in the past with no luck, it needs really dark skies. I think another problem is it’s massive!!...5 times the size of the full moon, so the trick may be to find an edge of it so you can distinguish it from the background space. An eyepiece/filter providing high contrast would assist I think 

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First, just be sure that you have found the right cluster - it's quite distinctive and easy to match with a picture.

Then yes, a "doughnut of emptiness" would be what I saw the other night with a 6" in Bortle 4. Or rather, a portion of a doughnut, as it's quite large.
Depending on the sky darkness, and perhaps the magnification, you can convince yourself that this is actually a greyish cloud of nebulosity rather than a gap in the stars.

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5 hours ago, domstar said:

Is is possible to see through the eyepiece, and how difficult is it?

Yes it is possible and not only that it shows very well. What scope are you using? this matters re:eyepiece selection -and if I remember you have access to dark skies?

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@jetstream Hi, I have a 100ED refractor. During the winter I'm on the balcony- 20.55 SQM (from light pollution map) It's not dark but when it's cold (now) the transparency can be wonderful. The Virgo Messier objects are visible from the balcony. Last night Hubble's Variable Nebula was visible through the eyepiece and the Crab Nebula was visible but a little tricky. I know the Rosette is much bigger and I'm not experienced at such large objects but would like to rectify that. 

I know your advice on upping the magnification on galaxies really helped last year. What would you suggest for this? I have a 2 inch Aero 30mm (30x), a 25mm Starguider, a 20mm and 3 BCOs 18 10 and 6mm. I'm guessing the 25mm.

Anyway, just knowing it's doable gives me the determination to give it more of a try. Thanks.

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Ok, nice scope! The SW doublets work excellent on nebula IME.

Heres whats holding you back- at f9 your exit pupil with the 30mm is only 3.3mm. For these objects a 4.5mm-5mm exit pupil is in the strike zone. I use a 42mm Vixen LVW in my fracs with success.

The smaller exit pupil issue is compounded with filter use..which filters do you have?

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Thanks for the info. I have an Explore Scientific UHC. I can see the Veil a lot more easily with it but the improvement on other objects is subtle at best. I imagine it works better with larger apertures and more discerning observers. 40mm is interesting. I've been moving away from my 30mm because of the lightness of the background. I have a 32mm Baader plossl. That would be the best bet with the UHC? (for tonight)

Edited by domstar
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Yes, it's visible to me but only since I purchased the SW ED150.  The views through that are exceptional. I use a UHC filter too and a 28mm 82' EP (Explore scientific).  As you may imagine, the same gear trained on M42 creates an awe inspiring view.  I've only tried at home but I will give it a go up at the obsy where the sky is very dark when the chance arises.

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@Owmuchonomy Thanks. Hearing positive outcomes is very useful.  There's nothing worse for my determination than not knowing if I'm in the right place, or not knowing if I have a chance of success. Now I have the confidence to keep at it- I suppose this is the part of observing that I enjoy the most.

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Just now, domstar said:

Thanks for the info. I have an Explore Scientific UHC. I can see the Veil a lot more easily with it but the improvement on other objects is subtle at best. I imagine it works better with larger apertures and more discerning observers. 40mm is interesting. I've been moving away from my 30mm because of the lightness of the background. I have a 32mm Baader plossl. That would be the best bet with the UHC? 

Heres the deal- and some will disagree.

1. For seeing the nebula highest contrast an high transmission, tight OIII is needed.

2. To make these filters work right a large 5mm ish exit pupil is needed

3. The larger fl EP can make the sky lighter in lighter skies but with the OIII this works vg.

4. The Rossette is big- to avoid "seeing through it" use the largest TFOV you can. 1.25" EPs are out unless you just want to detect edges.

Dom, from 20.6 mag skies your scope can show it with the OIII-it might show dimly with the 30mm but a 40mm 2" ep is best.

These are just my thoughts.

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This should be possible with your scope, depending on sky conditions.

Previously I have seen the rosette from suburban skies on nights of excellent transparency with a ST120. It's about 1.25 deg dia.

From memory i used 30x, i had no nebula filter to use, it was pretty low contrast against the background sky, but visible.

On an average night,i would have had no chance.

Once you have the central cluster in sight be patient & keep looking.

How do you find viewing m33 Dominic?~ easier target,similar size againwith low contrast~a good practice run maybe?

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I’ve seen it a couple of times in a 106mm f6.5 triplet using a Lumicon OIII filter and, most likely a 31mm Nagler under pretty dark skies.

That gave a 4.75mm exit pupil and a 3.6 degree field of view. Right in line with Gerry’s suggestions, and it works! The large field of view ensures you see the edges contrasted against the darker sky which makes it easier to see.

63B57032-6F34-4696-8128-1E0D39C05CD6.png

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Thanks everyone. I had a really good crack at it tonight. Half the time I thought I had an edge or found a lighter patch but nothing that I could swear to. I think I was nearly there- then I moved up to the Christmas Tree Cluster and noticed that the conditions were less than perfect. I hope I get a night of transparency when the moon is waning in March. I feel I could be on the verge of getting it.  Anyway, I really enjoyed the challenge tonight even though it was just out of reach.

@SiriusB Good idea with M33. That one took me a few goes and now I often see it in my finder. I should have another go at it. It was another one when I felt like there was more to see if could just manage to observe a bit better/ get a darker sky/ buy a bigger scope.

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  • domstar changed the title to Seeing the Rosette visually
1 hour ago, JeremyS said:

Is that a scope I’ve missed Stu?

Possibly Jeremy, it was quite awhile ago. It was an Astrotech, very nice it was too, although the Tak does beat it in most areas including planetary; the one thing it did better was widefield because it was 690mm vs 740mm focal length. It would go to 3.7 degrees with a 31mm Nagler vs about 3.4 with the Tak, enough to be a bit more comfortable on the whole Veil. I use the Genesis for this now.

The very scope I owned was reviewed here by Steppenwolf quite some years back; I bought it as an ex review unit. Appropriately enough for this thread, it has an image of the Rosette nebula taken with it.

 

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10 minutes ago, Stu said:

Possibly Jeremy, it was quite awhile ago. It was an Astrotech, very nice it was too, although the Tak does beat it in most areas including planetary; the one thing it did better was widefield because it was 690mm vs 740mm focal length. It would go to 3.7 degrees with a 31mm Nagler vs about 3.4 with the Tak, enough to be a bit more comfortable on the whole Veil. I use the Genesis for this now.

The very scope I owned was reviewed here by Steppenwolf quite some years back; I bought it as an ex review unit. Appropriately enough for this thread, it has an image of the Rosette nebula taken with it.

 

Thanks Stu - a good read.

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I've only seen this target once under bortle 4 skies with my Helios Apollo binoculars. It looked like a faint ring of smoke around the main stars. I actually did a report on it:

It's a difficult target, but I think its surface brightness really benefits from dark skies, low magnification view and a large exit pupil. Adding the UHC and OIII filter to the binoculars also made the difference from not visible at all to quite obvious.

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If we ever get a clear, dark night again, I'll have a go with my Vixen ED102SS F/6.5. With the 31mm Nagler I get a 3.8 degree true field with that scope.

I have the feeling that I might have glimpsed part of this nebula in the past but it's been a long time ......

Good luck Gerry :thumbright:

 

Edited by John
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2 hours ago, John said:

If we ever get a clear, dark night again, I'll have a go with my Vixen ED102SS F/6.5. With the 31mm Nagler I get a 3.8 degree true field with that scope.

I have the feeling that I might have glimpsed part of this nebula in the past but it's been a long time ......

Good luck Gerry :thumbright:

 

Thanks John and I eagerly wait for your report!

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Under 21.5sqm I had an excellent view of the Rosette with my 15x70 Apollos using a combination of UHC/Nebustar II filters or OIII/Nebustar II, can't remember which pair worked best, but it was right there and a lovely sight. Just popped right out. A large object!

The first time I saw it with a 20" dob and 20mm APM 100deg eyepiece and 2" OIII filter, that was astounding, but couldn't fit it in the entire FOV.

I think my 12" dob at 1500mm focal length with just squeeze it all in.

Seeing it in filtered binoculars really gives you a good impression of overall size, but the darker the skies, the greater the reward.

I've managed it from home, c.20.4sqm, but it wasn't a show stopper. Past 21.00sqm with corresponding transparency, it gets better and better the darker it gets though anything with filters. One of my favourites.

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