Sunday, July 24, 2011
Eyeball Astronomy
There is nothing more relaxing than taking a chair out into the yard and looking up at the stars. The night time air is usually cooler and the sounds of the night are themselves a unique experience. If you can find a dark area of the yard away from streetlights and allow your eyes to dark adapt well you will see much more.
Two things can really make this more interesting. One is a planisphere. You can use this planisphere along with a red flashlight to help identify constellations. The other is a green laser pointer, which you can use to outline constellations and provide some visual boundaries for your eyes. If you use a GLP please be aware of the restrictions and dangers around aircraft, and never shine the beam from one of these in any other participant's eyes.
It costs nothing to do astronomy like this, and it is very relaxing for your eyes to simply "hang out in the dark. "
Tuesday, July 19, 2011
A Boy and His Telescope
It is a cold, bright sunny day in the deep of winter in 1973. The sun is deceiving because the temperature outside is just a bit above zero. There is heavy snow on the ground, almost two feet deep in places.
"Son", she hollered, "what are you doing?” "I'm going outside to build a snow fort Mom" he said. "Wear your winter boots, its cold out there." He largely ignored her because he is in his own world.
As the afternoon progressed, an area in the front yard is transformed from a knee deep area covered in snow into a cleared spot with four tall walls made of snow blocks. The sun began creeping lower in the clear blue afternoon sky, and the cold air was deceiving, you could see your breath in it.
"Get in here and get cleaned up, it's almost time to eat", she said. "Yes Mom" he replied.
After dinner, he went to his room, and dug out his telescopes. He had a 40mm refractor with a fixed eyepiece on a shaky tripod, and a 50mm refractor on an equally shaky tripod but this one allowed the Japanese sized eyepieces to be removed and changed out. Somewhere along the way, he had collected his Dad's binoculars, a nice 7 x 50mm pair of Nikon's. All of this was carried carefully out to the snow fort, along with a planisphere.
And on this dark moonless night, somewhere in the Cypress Hills in the small town of Elkwater, Alberta, Orion began to appear in the sky. There it was, the great Orion Nebula. Sirius, the dog star shone brightly in the cold winter night’s air. Where is M41? Hey look, there is the Pleiades, get the binoculars. Snow makes great chairs because you can mold it and lay in it comfortably as long as you are dressed warm. There is Taurus; hey there are the Hyades, oh WOW!!!
At 9 PM it was time to come in. But a whole lot had been gained that evening. And in the evenings to follow, the knowledge began to grow because with each new constellation learned it became easier to learn the ones beside them. New objects were added to the lists of things to see. New books were read.
Without even realizing it, I had spent that entire day building my first ever observatory, and although it's usage would be temporary at best, it served its purpose of keeping the light moving cold night air at bay and gave shield to the one distant streetlight. It served as a place to retreat with my telescopes and enjoy my boyhood hobby. Armed with only the limited gear at hand, a planisphere, and a desire to know more about the night sky, these are the humble roots of an amateur astronomer. And what's funny is to this very day, nothing has changed.
Monday, July 18, 2011
Why We Observe
Have you ever wondered what drives someone to get up in the middle of the night and pack a telescope outside to be alone and look up at the stars?
Think about this. Ever since the beginning of time, mankind has been looking at the stars. In the past, they became the centers of great tales of folklore. Mankind has always dreamed of what answers they may hold.
Today our view of the heavens is diminishing rapidly. Not so long ago, and even in America, people could step outside into their backyards and look up on a summers eve and see the band that we call the Milky Way galaxy. On the astronomical time scale, 50 years is insignificant.
Yet it is this same diminishing view that drives those of us who do this hobby, to seek that time alone, when we sync with all that is out there, and inhale photons from a time long before the arrival of man on this planet, even before this solar system began. We are driven to photograph and observe and share the experience with others, to wonder aloud of all the promises that space holds for us as a species, and just for one brief shining moment to forget all our earthly concerns and realize in some small way how insignificant we truly are. We are tour guides of this amazing place we call the cosmos. We use our tools to learn and share. It is our nature. We differ very little from the warrior hunters of the past who looked up and saw virtually the same things we are looking at tonight, for in the cosmos, mans place is almost non-existent.
Saturday, July 16, 2011
The Basics of Astrophotography
If you are reading this article, there is a very good possibility that you are interested in learning more about astrophotography. Perhaps you own a camera like the one pictured above and believe that you would like to try your hand at taking some sky shots. Good. This is how it begins. And how far you go with it is up to you and your budget.
You will need a tripod and a remote timer or cable release for an older 35mm SLR. At the very minimum, you need a means of keeping the camera stationary, and a means for tripping the shutter. The adjustable alt-az head may be nice for framing but is completely optional. With this setup, you can do about a 30 second exposure with fast film or high ISO settings and achieve some interesting results. This is the least expensive and least intrusive means of getting into astrophotography. In many ways it is also the most fun because at no point will you invest less energy and achieve greater satisfaction than when beginning at this point. The problem is, most guys get hooked at this point and they want to get up to the next level. You can do this fairly inexpensively, providing you have a telescope on a tracking mount and a means to mount your camera on the tube.
This image shows my old trusty Minolta X-370 astrophotography 35mm SLR mounted on a special rail I had made for my telescope cradle. The nice thing about piggybacking is that with short focal length lenses like the 50mm f/2, and even fairly decent polar alignment, you can achieve some very spectacular results because you can now increase your exposure times from over 30 seconds to perhaps 30 minutes or more, depending on your sky conditions. I have always enjoyed this type of astrophotgraphy because it requires minimal intervention and delivers excellent results in a consistent way. You can substitute a DSLR in place of this camera and do about the same thing, taking a number of successive shots and later stacking the images with Deep Sky Stacker to achieve a very long exposure time equivalent. Digital technology is superior to the old film in that if you get a bad frame from something like a jet or a satellite you can simply leave the frame out, not so with the old methods.
If you don't own a DSLR, a cheap way to get into imaging is with something like the Meade Lunar and Planetary Imager, the LPI. The LPI and a laptop allows you to shoot images of the moon and planets. This webcam device can deliver many hours of enjoyment and will allow you to begin to use software for capture and control of your equipment. At this stage you will want a good equitorial mount with the ability to track sky objects, and a barlow lens or two to achieve a better image scale. The degree of difficulty is higher than with piggyback work simply because focus becomes more critical as does the ability of the mount to carry the load and track properly.
By this point you are very interested in doing this astrophotgraphy thing. In the days before autoguiders and digital cameras, a setup like the one pictured could let you couple your camera to your telescope and guide the stars with a fairly high precision manually, at least good enough for film. Doing this with today's technology is even more interesting.
First you will need a T ring and T adapter. This allows you to couple your camera to the focuser on your telescope. You will need a means to control your camera. You can do this with a remote timer, or even with software like BackyardEOS, which is what I am now using. And you will need a means of guiding. Guiding is a process of making minute corrections in your tracking that are sufficient for your image scale to make images appear pinpoint without egg shaped stars. More often than not, this is being done with autoguiding, a means whereby a second camera is being used in conjunction with a software package like PHD Guiding.
This final image shows a setup similar to this mentioned, where the camera lens is now the telescope. This is called prime focus. You can see the guide camera and guide scope on the right, and the camera coupled along with a T ring and T adapter to the focuser. Beyond this you may wish to place specialized imaging cameras at prime focus to do even more precise work, but be warned, by the time you get to this stage your investment will be considerable and your knowledge will be very extensive. Many make the mistake of beginning at this stage, and although they eventually get fairly good at it, they find the curve to get there pretty steep. Plus I just think you miss out on a lot of the joy of what this is all about if you don't go through the steps first. Hopefully this article will help someone out there to be inspired to become the world's next astrophotographer.
Wednesday, July 13, 2011
My Little Telescope Team
Here is what I am now using to do all of my astronomy. This has been two years in the making, buying a bit of gear here and there, some of it was rescued, and all of it has been used. At the heart of my equipment is my well equipped LXD75 SN6. I have purposely built this system to be an imaging system, however it has the capability to also be used visually. Most recently I have had to replace the right ascension stepper motor drive, most likely a victim of a bad power cycling experience in the dark. I am complimenting this system with an old rescued Meade Telestar, which is also a GoTo model telescope. When I began this endeavour, I started off with the Garret Optical 15x70 binoculars being used on the Orion Paragon tripod package, and while the tripod does work, it is not without its weaknesses alike. I picked up the Short Tube 80 model telescope to use as a guidescope mounted on an accessory bracket that I had custom fabricated to mount on the SN6 cradle. Below the ST-80 sits the power supply center for the evening.
This closeup shot of the SN6 reveals a few new additions that I have added to my unit. I found the ST-80 to be very heavy on the scope as a guidescope, and some of this may have had to do with placement, so I have purchased the Orion mini-guider and mounted it into the stock Meade finderscope's location. I have also modified an Orion electronic focuser to be used on my unit to provide for more simplistic camera focusing which can be a very difficult task at the best of times. The accessory bracket is also visible and will be a great spot to do piggyback astrophotography. The Meade DSI unit installed in the mini guider will make an excellent wide field camera as well to experiment with when it is not serving in its role as an autoguider.
Overall I really love all of what I have assembled. It cost me a fair price but not compared to many systems that I have seen out there on the web. It is all compact and lightweight and portable. I have the ability to do everything from lunar eclipses to deep space imaging. Not pictured in these photos is my accessory case with eyepieces, various brackets, a lunar planetary imaging camera, and my Canon Rebel XS DSLR. I have purchased a software package called BackyardEOS to use with the DSLR and in the little that I have used it I am very impressed with its features.
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