View Full Version here: : M20 Trifid Nebula
16-04-2012, 10:43 PM
Trained my scope at M20 last night.
Just not sure if I am looking at the right object.
Would anyone has a picture of how the Trifid nebula look like at 35x and 60x through a scope ?
I mean, the actual eye shoot view when you peer into your scope?
17-04-2012, 01:40 PM
You must have been up late - or very early in the morning!
I think you need a 5" and around 100x to see the bifurcation in the nebula. (the dark lanes that is) and very dark and transparent skies, if using such a small scope.
17-04-2012, 02:10 PM
I would imagine that for M20 would need to wait until 4-5am at the moment to see much. In my 12" at 113x I can see the dark lanes with averted vision. Needs a really dark sky to get them with direct vision.
At lower power, say 67x that I used to have with the 24mm Pan, they were really more of a hint of dark lanes.
Looking forward to trying the new Ethos on it!
19-04-2012, 07:22 PM
Please do not take this the wrong way, but it is good manners to respond to posts that answer your questions. I note on your post history that you have posed questions regarding finding objects before, and though a number of answers were posted, you did not come back and say which was helpful. Responses to questions are as much a part of this forum as posting them in the first place.
19-04-2012, 10:01 PM
Can I ask what telescope you are using? Magnification alone isn't a good gauge to help you with. The size of your scope is a better indicator. If your scope is 4" in size, you'll struggle to see much with M20 other than a roundish smudge. A 10" scope and a dark sky with good conditions and you'll never forget your first look of M20 - I never have!
M20 is one of the objects I've got penned in for a sketch this year. Here's hoping.
In the mean time here's a link to a sketch of M20 using an 8" scope (http://www.asod.info/?p=1938) by Janis Romer, though it doesn't note what magnification was used.
20-04-2012, 08:59 PM
I am using an 8" sct.
Is this sufficient aperture to view the Trifid?
My gut feeling is,it is probably on the small side.
Trying to make the best of it.
21-04-2012, 07:39 AM
An 8" SCT is plenty big enough to view the Triffid. What you need are dark skies.
21-04-2012, 07:48 AM
That is a sexy beast, your 8" SCT. I love mine, and it is some 30 years old!
Your CAT is certainly enough to see the markings in the Trifid. From a light polluted area you may struggle though. A nebula filter of some type will help make the marking stand out some more.
Your SCT is also capable to showing the dark pillars in the Eta Carina nebula. There are three skeletal like fingers that reach up into the brightest "leaf" of the nebula out from the sharp, straight edge. I've seen them through my SCT, and it's optics are not coated, and from my home in Sydney too.
Don't be affraid of upping the magnification with either nebula. This will darken the background adding to contrast. If you don't see these features at first, be patient and use averted vision. These features are DARK, and against a dim nebula. See this as a measure of your skill. If you can see these features you are doing very well. The dark pillars of Eta Carina is a good target to try before bashing the Trifid. You'll be able to get your eye in with this sucker first. It is very, very detailed. The bright leaf I mentioned also holds the star Eta Carina (really crank up the magnification with this bright red star and you'll see the Homunculus Nebula around it), the Keyhole feature, plus six other open clusters and a three shockwave bubbles (of which the Keyhole is one of them). Eta will keep you busy while you wait for M20 to rise.
21-04-2012, 01:05 PM
Thanks Alex....dark sky in my backyard is a rare event.
Just thinking, on how to improve on my view.
30-04-2012, 05:19 PM
I'd also add that a nebula filter helps a lot in seeing these features in both the Trifid and Eta Carinae - for me, the main dark lane in Trifid is quite easy with an 8" Dob plus filter from suburban skies, though the nebula is usually just a pale round smudge without the filter.
25-05-2012, 09:31 AM
Thought I'd give a little update on my own recent experience with M20.
A couple of nights back here in Sydney we were treated really good seeing conditions. Dry, dry, dry was the order - no dew! can you believe it :eyepop:!
Being a weeknight, I only had a half hour session with my 8" f/4 dobbie. Using a 13mm eyepiece, 61X with this scope, I was able to make out the dark lanes within M20 without a filter. Direct vision had them tricky to make out, but with averted vision they were very clear. When there is more moisture in the atmosphere, the lanes are bugger all there.
But keep in mind that my sky to the east is ok, light pollution wise. M20 wasn't quite at zenith yet, so my view was as good as it gets for me. If I was located more centrally within Sydney I may not get the same view.
An OIII filter helped a little, and an NPB filter wasn't upto the task for this object and the urban skies.
If you are an urban dweller like me, it is surprising how much detail you can still make out in DSO's from the fringes of nasty light polluted skies. If a two hour trip is too difficult to manage to get to a dark site, but a one hour trip is more manageable, you can still find it fruitful.
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