53 replies to this topic

[rinalmj]

I have had trouble seeing detail in M1 and am interested to hear other people's experiences. I have observed M1 three times in the past few weeks, all on moonless nights when it was favorably positioned in the sky. I am using a Zhumell Z12 dob and typically estimate a limiting magnitude of around 5.5 from my location.

I have tried various magnifications, ranging from 50X to 175X, but have been unable to make out any detail. At low powers, M1 appears as a nondescript gray haze, with the area immediately surrounding it apparently void of stars. At higher powers, the image dims significantly.

Should I be seeing more, or is this fairly typical?

[Tom Polakis]

What you are seeing sounds typical. Take that same 12" scope out to a very dark site, and you might begin to just barely see the filaments. This drawing is an excellent rendition of the Crab Nebula through medium aperture. Apparently it was lifted from Astronomy Sketch of the Day, but I could find out from that site who drew it.

M1 Drawing

Tom

[bgman]

For me it took higher magnification (250x-350x works well) AND a good OIII filter to bring out the filaments. The overall view is dimmer this way but it really starts to look like the pictures you see in books. Until I used this combination, the details just would not pop for me no matter what. You need contrast, and darker skies will definitely help. I hope that helps!

Will

[blb]

I have never seen any filaments, with or without an OIII filter. It always appeares to be an oblong hazy spot. On the best nights of seeing I can see what looks like a notch or a bite out of one end of the nebula. To me this has always been a very disappointing object to view.

[blb]

... Apparently it was lifted from Astronomy Sketch of the Day, but I could find out from that site who drew it.

M1 Drawing

Tom

Tom,

I think his name is Michale Vlasov of Israel. He goes by Michael11 here on Cloudy Nights. He really does good work with his 8-inch dob and posts here too.

[Matt2003]

My most recent posted log has the same description Buddy just gave. I see a peanut or notched oblong shape in my 8 inch. Someone else also said their Orion 14XTi shows about the same thing. Only I bet its brighter.
I've never gotten improvement with either of my Nebulae filters.

Clear Skies,
Matt

[hbanich]

A OIII filter and true dark skies are essential to see M1's filaments as has been already been noted, but even then you'll only see portions of the brightest ones. I've seen a few with my 28 inch f/4 scope and a couple years ago had a chance to see M1 through the 90 inch Bok scope on Kitt Peak, also using an OIII filer. I could see nearly all the filaments seen in photos - it was a great sight! - but even so they were still quite faint. Without the OIII only the brightest ones were seen - the filaments of M1 are a tough nut to crack.

[sgottlieb]

As far as the filaments, this is generally what I see in my 18-inch on a good night --

18" (11/14/09): at 175x and OIII filter an obvious brighter filament is visible that begins just south of center and extends WNW towards the west end. This filament is brightest (or has a brighter knot) at its eastern end near the center. A fainter filament begins near the same point south of center and extends towards the NE. The two filaments, if joined as one, extend nearly from the west end of the Crab Nebula to the east.

[Feidb]

I usually see a fat S shape with some flaking around the edges and a fainter round halo overall. Sometimes I see what I call mottling, rather than filaments. Maybe I should use the word filaments instead, but regardless, I've never described them in the same detail as Steve has according to my notes. Just general impressions. Most nights I see a haze with details along the outside but rarely see much on the inside. When I have seen "mottling" inside, it has been a good night! Magnifications have ranged from 70X to 102X. When I've tried an O-III, it has practically destroyed the image so I generally don't use the filter. A UHC has helped in the past (a little bit). This is one nebula where, to me at least, the O-III doesn't help much. Steve, I'm surprised you were able to use it with such good results.

[sgottlieb]

When I've tried an O-III, it has practically destroyed the image so I generally don't use the filter. A UHC has helped in the past (a little bit). This is one nebula where, to me at least, the O-III doesn't help much. Steve, I'm surprised you were able to use it with such good results.

I would suggest trying the O-III again. It will mute the overall brightness of the Crab, but the *internal* filaments do stand out better. Magnification is certainly important also, so try higher powers if the seeing allows. But the OIII filter and dark skies is the ticket to see the filaments.

[Feidb]

Steve,

Next time... Thanks.

[David Knisely]

Here is what M1 tends to look like in my 10 inch Newtonian at around 100x using the DGM Optics NPB filter at my dark sky site (ZLM 6.5 to 6.8 typically):

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[uwe_glahn]

A very realistic sketch of M 1 with 16" can be found here

My experience are that you need 12" + [OIII] at minimum to see the brightest filaments. With 16" it should be no problem.

With 27", 366x and [OIII] the Crab dissolve in endless structure which can be sketched only with problems. Superb object!


to homepage with invert version (Java on)

uwe

[nytecam]

Some interesting observations and sketches of this facinating object I've never seen it more than an oval blur

My one-shot-colour pic from last week - the tiny star abutting the 'double-star' immediately north/above neb = mag18.2 :o Below is a channel split of the main image into red/green/blue and may be a guide to visual obs. Here's a close crop showing M1 pulsar

[Matt2003]

David's sketch comes the closest to my own view of this object a couple of weeks ago.
Nice work..
An interesting object, but not spectalur to view. Except if you know its history, than it shines.

Clear Skies,
Matt

[Matt Lindsey]

Last year (I think) in S&T Sue French mentioned using an OIII on the Crab. It does help the filaments and knots stand out a bit as Steve also suggested above. The other night, from an orange zone with a 5.5 NELM, I could clearly see a brighter area on the South half of the nebulosity, extending somewhat E-W.

[rinalmj]

Thanks to everyone for your insights. It is always interesting to hear different perspectives on observing the same object.

[hbanich]

I had a rare clear night this past Friday and after moonset, and being inspired by this thread, had a nice look at M1 with my 28 inch f/4. The sky was so-so: 21.15-ish SQM, transparency about average for western Oregon (not so much) and poor seeing. But hey, it's usually raining so this was great!

After flipping back and forth being unfiltered and OIII views I decided to sketch both to show the difference - at least to my eyes through my scope. This isn't the most detailed view I've ever had of M1 but it was pretty good. I used 250x to 400x for both sketches. They barely look like the same object as there are no hints of the filaments without a filter and the shape/orientation of the overall shape seems different. The main body of M1 has a mottled texture with the OIII but is very smooth looking in the unfiltered view. I had a sense that a bunch of fainter filaments were just barely unseen and if the sky was darker/more transparent/steadier they might start coming into view. The perimeter of the OIII view seemed ragged while it was smooth without.

Anyway, just another perspective on this fascinating object.

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[lunar]

I myself have never seen much in M1 either, and definitely not the filaments. Then again, I don't have a deep-sky filter to my name and probably won't for some time. It'll be around for a long time though, so I have plenty of time to get around to it.

Clear skies,
Brandon Doyle

[Akarsh Simha]

Yes, OIII will make the filaments stand out. I like the shape of the boundary is best unfiltered, but would use OIII for the filaments.

[Matt2003]

The second sketch definitely says it all for the Crab in my 8 inch without filters.

Clear Skies,
Matt

[J Lowrey]

Howard, Looks like from youre drawing on the bottom that you got the Crab Pulsar in M1. If I am looking at it right.

Any one ever try for the Crab Pulsar (PSR B0531+21) ??

[Akarsh Simha]

Jimi Lowrey! ^:-)^

What's the smallest aperture that is required to see the Crab pulsar?
Have you managed to do it with the 48"!

[uwe_glahn]

Akarsh, with 27" the pulsar is a easy target. Near the center of M 1 you could pick out a closely double star. The fainter component is the pulsar. From the difficulty similarly to the separation of the double Quasar in UMa. I think the minimum aperture is around 20" to separate and see the pulsar.

[J Lowrey]

Akarsh, Its around 16 Mag if I am remembering right. Its a stellar point so it should be easy in you're 18" at a dark site. The main thing is to have a good finder chart. I have seen it with a 16" many years ago on a really good night.