Crab nebula in the burbs?

[toc]

For the last few nights I have been trying in vain to see M1 in my Celestron C8. I live in the northern burbs of Melbourne, but I was kind of expecting to see at least a very faint smudge :lol:

Im pretty sure Im in the right spot - the HEQ5pro seemed to be nailing other objects.

What sort of skies are needed for the crab?

[timmo567]

Thought I'd chime in since I've also had a few cracks at this with none of them being successful. I have quite dark skies at my place in north QLD (15 mins outside a small town). I'm a beginner but each time I tried a little bit harder and printed out exactly where it should be but never managed to see anything. This is with a 10-inch dob so I'd also like to know the secret assuming there is one

[mental4astro]

I've pinned the Crab from my home in central Sydney through an 8" dob without a filter.

It isn't a bright object, and it is small.

To find it, this is my star-hoping method, first use binoculars to find the necessary stars from urban areas:

First find Zeta Tauri, it lies just west of the tip of Orions 'club'. Immediately north of Zeta are two sixth magnitude stars (less than 1degree north). M1 lies in a staight line with these two sixth mag. stars, away from the 'club's' tip, almost the same distance that separates these two stars.

Use you lowest power to find it first through your scope, looking for a tiny disk of blueish smoke. If you think you've found it, you probably have. Verify with a med. power EP.

I use the Asahi 8.5 mag. charts which I down loaded via the Beginners forum stickies. The Crab is on chart number 56.

Good luck,

Mental.

[goober]

I've tried many times to see the Crab from Oakleigh ... 8" dob, 12" dob, ETX 90, 4" refractor. Never seen it.

But... out of Melbourne under dark skies, you'd wonder how you missed it. So obvious....

Light pollution dongs this one. But... if you're in the northern suburbs, I'd have thought you would have a fighting chance.

[PhilW]

It is a low surface brightness object, and is also low down in the sky. I wouldn't bother looking for it unless you're under a good dark sky (like Heathcote or the Briars). When, as Doug says, it is suddenly there.

[telecasterguru]

I have tried a couple of times with my 10" dob with no success. Time to have another go.

Frank

[DavidU]

I have seen it in my 6" refractor under dark sky's.
I will try the 12" under suburban Melbourne sky's and see how I go.

[Lismore Bloke]

I've seen it without difficulty from suburbia in the 12", although it's not exactly spectacular. I don't know if a UHC filter will improve it.

[stephenb]

25 years ago this was one of the first objects I looked at with a homemade 6" Newt from Sunbury and made out a small smudge, no problems. After 25 years of increased light pollution I struggle to see it from the same location with 8" Dob. Also after 25 years my trees have grown. Haven't tried it with the 16" yet as every opportunity I get there is either a Moon, or cloud, or work etc.

[GrahamL]

I guess it would be a difficult object near any of the big cities to the south any light pollution near the horizon would probably gobble it up as its not overly high up north. .. .. good luck :)
.
My 9x63 binos show it up easily and it looks fairly bright in the 12 "
Keep looking Tim , you will find this one soon enough.:thumbsup:

[barx1963]

I can see it very easily from my backyard in Colac, lp is moderate here, but is worse to the south. Keep trying and wait for the best seeing!

[seeker372011]

cant see it from home

easy from linden

[toc]

Guess I will have to wait until easter when I get back to Huntly...(outer part of 'greater Bendigo' - has pretty dark skies)

[mental4astro]

I had a go last night from home. Couldn't see it this time. There was too much humidity and low cloud that made the back-ground sky glow too bright, :(. Was also in the direction of the CBD, which doesn't help. Needs to be a little more easterly, too late now.

[telecasterguru]

I had a go last night but no go. Too much light and too many trees.

Frank

[stephenb]

Tim, I used to observe in the middle of the Whipstick Forest years ago. Nice and isolated. Great spot.

[mental4astro]

If sky's clear tonight, I'll have another go with a Nebula Filter. I've got an 8" and a 10" at my disposal to have a go with, :prey:.

[ericc]

At home Maitland(in the burbs) with my 10"dob its a very very faint smudge--but at a dark site no worrys to view(although its still a very ordinary and fairly faint object)but maybe thats because I a newbie?

[pgc hunter]

I can vaguely remember observing M1 with my 10" dob from outer Melbourne, appeared as a faint oval glow.

[Terry B]

By way of comparison, I looked at it last night with our clubs 14"SCT under our pretty dark skies.
It was a bright glow with a hint of the whispy structure you get in images.
It half filled the field with a wide angle 32mm eyepiece.
Very nice.

[Rob_K]

At the other end of the scale, with a 4.5" reflector it's very dependendent on sky conditions. From my backyard in good skies it's easy to see as an oval glow, but very even and never a hint of structure. When the transparency goes off even a fraction it becomes quite difficult to see. With a tiny bit of skyglow, forget it - move on to M42, LOL!

Cheers -

[Rev]

The Crab is underwhelming in good and poor seeing. Under my semi dark coastal skies it is a grey oval smudge in an 8"sct. I observed it on Feb 10 in my 14" and while showed some subtle texture but I must admit it's low surface brightness still leaves me underwhelmed. Perhaps it's fame as "the Crab Nebula" and Messiers 1st object builds my expectations too high.

[Vanda]

Will try Mentals approach in finding it with my 150 Refractor next time - have not seen it yet - Perth's night glow is a problem though - will try a UHC filter as well.

[Lismore Bloke]

While outside on Saturday night I spotted the Crab pretty easily as a faint grey oval in the 20x80 binos, along with NGC 5128 and lots of other DSO's.

[mental4astro]

Tough alright!

Had a go tonight with my 10" f/4.9. It lies directly over the city from my place. Only spotted with a 15mm EP and a nebula filter. Just. Not good seeing either. Even M42 was far below par.

Not a problem with my 17.5" from home. Too easy with such grunt.

Intrigueing to think that Messier spotted this one and missed much brighter objects in forming his first catalogue.

[ngcles]

Hi Alexander & All,



Yes I agree, it is not a particularly easy object from suburbia, though a UHC or OIII filter improves it somewhat and it is certainly visible from suburban Engadine in my old 25cm at low-moderate magnifications with a filter.

It is not really surprising that Messier saw it -- it was almost at Zenith in his sky which was somewhat darker overall that the suburban skies of today. He also saw it while observing a comet that passed almost straight over the nebula! Messier didn't discover it though -- it was found by Bevis about 25 years earlier.

We also have to remember that modern values show the whole nebula is now about 13ly across -- a size it has taken 1000-odd years to achieve. Back 250 years ago it was probably more like 8ly across and accordingly would have had higher surface-brightness than now (the integrated brightness is certainly no more than it was 250 years ago and is probably a bit less). In fact, the surface-brightness probably would have been about double then compared to now.

As for nowadays, the red-coloured tendrils that were once the outer envelope of the red-supergiant progenitor star (mainly ionised Hydrogen & Helium) are not really visually observable unless you have a giant telescope. They record well on film and CCD that is much more sensitive to H-Alpha emission.

The part that is more readily visible is the slightly smaller-sized, diffuse, blue emission which is by-and-large powered by synchrotron radiation. Synchrotron radiation is produced by electrons being accelerated within strong magnetic fields (pulsars have extreme magnetic fields) to velocities close to c.


Best,

Les D

P.S 990 -- nearly there!!

[Paddy]

Very interesting - this explains a lot!

PS Looking forward to 1000+ of your posts - they are all gems.

[DavidU]

I had a very quick look last night with the 12" and couldn't see a thing.
I will try again tonight.

[tonybarry]

From Werrington, near Penrith (Sydney), I saw M1 just once, on the 18th January this year. LX90-8" GPS UHTC with a f/6.3 reducer. The object was at the limits of visibility, and if I did not have the Goto mount I would never have been able to locate it. Light pollution was mainly to the east, but was moderate to high.

I used a GStar-EX to acquire M1 - the low light ability of the camera was the difference between moving on to something else, and spending three nights capturing frames. Once the object was firmly in the centre of the screen, I whipped out the eyepiece (18mm Meade series 5000 UWA) and could ... just ... see it.

This was the second time I have seen M1 visually; the previous time was at Linden, the WSAAG's dark site. There it was quite visible.

Regards,
Tony Barry

[fragchamp]

Interesting Les.

I saw this target once and found it too uninteresting to return to. It's one for the photographers.

[RobF]

Fascinating too to read about objects that have changed over the last 100-200 years, especially "faint fuzzies" like the Crab neb. I enjoyed this info too thanks Les.

[seanliddelow]

I have seen M1 in my 12" Dob from moderately light polluted skies.
It is a very boring shapeless smudge even in a 12" with no sign of structure. Sometimes I wonder how Messier even saw it at all. Its even harder to see then a galaxy cluster in Eridanus from my skies.:lol: