Lessons learned from Orion's sword

One of the more enlightening moments I had last year was when a visitor to Driftway Observatory peered into the 15-inch and asked me if the three stars in a row she saw were Orion's Belt.

It was a good question. We had just been looking at his belt with our naked eye, then she peered into the telescope and saw a lot of confusing stuff and three stars in a row that look something like the belt. Of course the telescope was magnifying things considerably and looking at an area of sky about one-tenth the size needed to take in Orion's belt, but the question made me understand how disorienting the jump can be from naked eye view of the heavens to the flipped, upside down, magnified and brightened view in the scope.

This disorientation is something I hope to try to rectify with video astronomy - not for me, though I'm finding the images fascinating as well - but mainly for those who are just setting out to explore the heavens. The images below were taken with this in mind. They are not intended as examples of polished astrophotography, but examples of what I feel we can do "live" with a video camera and television screen to prepare people to use a scope and to help them understand what they see. With a red screen preserving night vision, people can move back and forth between video images and what the scope reveals visually.

I used my new 7-70mm zoom lens on the Color Hyper MallinCam, lashing it to the 8-inch LX90 scope and centering it all on the Great Orion Nebula. My goal also was to learn more about the lens and camera, but I think the results shows how the stars appear from a naked eye view , through binoculars or a small telescope, to a highly magnified view in a popular model of amateur telescope.

(Click image for larger view.)

To start out, though, and help orient those with no, or a little familiarity with this constellation, I thought the shot above taken the same night (October 26/27, 2006) by my friend and fellow amateur astronomer Dan Chieppa in New Bedford, MA provides a good context, showing nearly the entire constellation and, more importantly, some foreground objects that add perspective to the typical naked eye view. As Dan explained, this is a " tripod-mounted 10 second exposure." He used "a 28mm lens on my Canon 20D camera with the ISO set at 1600." Click the image to see a larger version. Please excuse the side excursion, but this shot reminds me of what Robert Frost says about Orion in the beginning of my favorite poem, "The Star Splitter:"

‘You know Orion always comes up sideways.
Throwing a leg up over our fence of mountains,
And rising on his hands, he looks in on me
Busy outdoors by lantern-light with something
I should have done by daylight, and indeed,
After the ground is frozen, I should have done
Before it froze, and a gust flings a handful
Of waste leaves at my smoky lantern chimney
To make fun of my way of doing things,
Or else fun of Orion’s having caught me."

What I imaged was just the lower half of the giant hunter, focusing on his sword which contains the nebula. Orion's most distinguishing fetaure is the row of three stars in his belt. Very unusual to have three bright stars like this in a line, so it's a "signature" of Orion. These are at the top in my images.

The first set of images below - and I urge you to click on them for a larger view - are taken with the zoom lens at its widest setting of about 7 mm. The image on the left is a 2.1 second "integration," the next one a 6 second, and the next a 12-second. "Integration is a tehnical term used in video astronomy, but you can think of these as 2.1, 6, and 12-second exposures. The longer integration, of course, gathers more light and shows fainter stars. I think the three roughly simulate a view of Orion in mildly light-polluted skies, a naked eye view in excellent skies, and the view through a small, wide-angle binoculars.

In the second set of images we zoom in and focus our attention on the belt where the real object of observation is the star-birthing region known as M42, or the Great Orion Nebula. It is the blur of light near the center of these images. I feel these view are roughly similar to what you would see with large astronomical binoculars, or with a small telescope set at low power and using a wide-angle eyepiece. One function of a telescope is, of course, to magnify - and magnification certainly helps us see detail - but the lesson that should be drawn from this sequence is the importance of a telescope in gatheing more light. The bigger the objective lens or mirror, the more light you gather - and the more light you gather, the easier it is to see fainter objects, as well as see detail in objects that you magnify.

In this third set of images I have removed the zoom lens from the camera and instead used the 8-inch, LX90 telescope like a huge lens. Now the focus is just the Orion Nebula and increasing the light gathering power - by increasing the exposure - is much like peering deeper and deeper into something. (At first glance it may seem like there is a magnification change from image to image - there isn't. Just gathering more light each time.) (I used Photoshop to re-orient the view so it approximated the oprientation you see with the naked eye. You can accomplish the same reorientation when doing live video by simply twisting the camera in the eyepiece.) The appeal of the first image is if you look carefully you can just separate the four bright stars jammed together near the center that make up the beautitful "Trapezium" and provide much of the energy that allows us to see this nebula at all. In the succeeding images these four overwhelm the camera and blend into a single blob of light - but more and more faint detail is being revealed in the dust and gas clouds that will evetually coalese into stars and planets and hoptoads and people - perhaps. Incidentally, I continue to be enthralled by the point thatbigger isn't always better - and more light isn;t always better - it just gives you a different view. My use of large telescope - and video - have made me appreciate more what small telescopes deliver.

I wa sgoing to do a forth set of images with higher magnification, but as I watched the 12-second integration on th evideo screen it suddenly started to dim. I was shocked and my first thought was - "oh no, what's wrong with the camera?" But then it dawned on me - I was watching the nebula slowly be obscured by the leaves of a tree which was marching steadily eastward with the relentless spinning of our little globe ;-)

This nebula is about 1600 light years from us and we are only seeing here one small area of a region where stars are being born at this moment. For a historical overview, much more detailed information, and loads of pictures of this most fascinating object, go here.