Theme No. 2
Nebulous Extensions
This might seem like an odd theme, but it brings into play a whole bunch of ideas that have been discussed here: the human eye, experience, sky conditions and filters.
If you don't have any nebula filters, don't despair! These are not mandatory. Helpful, sure, but not mandatory.
First a little background as to why I've come up with this theme, and it will then make much more sense.
While I was thinking about what theme to offer, I looked at the picture I posted Thor's Helmet, and it reminded me of the two very important experiences I had with it - my first and second views of it. And this in turn what I've also come to learn with using my scopes, and why I don't use a tracking scope when I do any DSO observing.
What Thor's Helmet taught me about the sky - I first saw Thor's Helmet at the IIS Astro Camp some 6 years ago. I didn't know about it, and it was suggested to me as a target by a fellow Camper. And when I saw it through my 17.5" dob I thought it was freaking
AWESOME!
Well, it was a great first time view, but what I did not know was how the site we were using for the camp was crushing the quality of our sky - in a lush valley in the middle of agricultural/dairy country. A couple of years later I revisited Thor's Helmet from the Blue Mountains west of Sydney. The conditions here were totally different - on top of a bone-dry sandstone ridge 1000m above sea level. What the difference in location and the sky conditions it provided just blew my socks off when I looked at Thor's Helmet once again with the same scope.
What also influenced my view was how I used my scope. I was now aware that our eyes quickly lose their sensitivity at low levels of illumination, and that they need to be tricked up again to restore their maximum sensitivity, and this needs to be done constantly. And this is done by my constant nudge-nudge-nudging of my push-to scopes. A static image provided by a tracking scope will not provide this physiological trigger to refresh our eyes. So if you are using a tracking scope, YOU NEED TO PROVIDE THIS REFRESH MECHANISM by constantly tapping the side of the scope to induce a damn good vibration!
And the difference this will make will blow your socks off too! It really will now that you are aware of what doing this does to your eyes, either the constant nudge-nudge or the strong tap of the scope! Those oh-so-faint extensions of a nebula will all of a sudden just keep on going and extending!
There's a bunch of great nebulae that have fantastic extensions that at first glance just don't stand out, and if you rush you just won't see, and you don't need a 17.5" scope either! Sometimes a smaller aperture is a better bet too. Now, if you are already familiar with the objects listed below, do revisit them now that you are armed with new insight on how to best exploit your eyes and scope. And BE PATIENT! DAMN IT!!!
* NGC 2359 - Thor's Helmet - well of course...
* M42 - The Orion Nebula
* NGC 3372 - Eta Carina Nebula
* The LMC - not a nebula, but a galaxy, and a face-on spiral galaxy whose two faint arms can be traced with fast f/ratio scopes and dropping the magnification as low as possible/practical. The first pic below shows how the arms are orientated in the sky when you look up at the LMC. The second pic is my sketch of it using a 4" f/5 refractor so the image is flipped left-to-right. The LMC is an amazing task-master that is all too often ignored, and it hides it true treasure in plain sight from impatient eyes! And the third image is a close up of that sketch which was done on an A1 size sheet of paper - a BIG sketch!
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* M17 - the Swan Nebula, a winter nebula
* M8 - the Lagoon Nebula, also a winter nebula
* NGC 3576 - the Statue of Liberty Nebula. This one is really difficult unless you are using a BIG scope, say 12" and BIGGER. You NEED to be particularly patient with this small but oh-so-intricate nebula in order to really get to see its full extent, which is enormous really! Below is my sketch of it from a site with poor transparency. I can't wait to revisit it from the Blue Mountains site I use. Can't see the Statue of Liberty here? Do a google search for it!
~x.X.x~
What all of the above require is PATIENCE!
It is the only way that you will actually get the most out of the object, your scope & your eyes. Rush, and you will only cheat yourself. The reward comes from slowing down, understanding the way our eyes work, and using your scope in such a way that it will work best for your HUMAN eyes.
I mentioned earlier a little about site selection. It is something that next to no amateur astronomers ever give more than just finding an open grassy field. But the truth is that open grassy field is actually the worst that we can use for astro!!! If you would like to read more on how to find the best site for astro, have a read of the article I wrote on the subject:
Selecting A Site For Astronomy Purposes
This is a topic all of its own. I had submitted the above article for inclusion here in the Articles section of IIS, but nothing came of it. That's why the link to my own blog.
Happy, and patient, hunting!
Alex.