Beyond the moon, the planets and the moons of many planets there is deep-space. An infinite assembly of galaxies, nebulae and distant comets. Intriguing stuff, but not easy to find and sometimes very hard to see. Here's how to explore deep-space and some of the fundamental equipment and conditions you'll want to consider.
To begin with, your ability to observe deep-space objects requires the darkest sky you can find. This usually means a remote location without domestic "light-pollution." It also means you'll want to schedule your viewing time during a new moon or before the moon has risen high into the night sky regardless of its phase. Deep-space objects are typically dim and your ability to gather light from the object is critical. You should also use a flashlight with a red-filter for any adjustments to your equipment to ensure your eyes remain dilated in the dark. Here is an article with tips on how to improve your viewing of dim objects.
Many amateur astronomers recommend a Dobsonian telescope for deep space. This is because large aperture Dobsonian scopes are typically inexpensive compared to refractors and reflectors of a similar size, but they have one critical limitation. They are not mounted on a tripod with a geared head, and while a motor drive is a possibility, it is a significant expense. Most Dobsonian scopes are physically moved by hand but with a little time and practice, you can compensate for the rotation of the earth while viewing a deep-space object. Their advantage is their ability to gather light. A critical consideration when viewing the distant, grey smudges of galaxies and nebulae.
Beyond the need for a dark sky and the light gathering ability of a Dobsonian is awareness of the location of the deep-space object. This can be done by triangulating it's location on a star chart or astronomy app with constellations and specific stars in constellations. When it comes to deep-space objects the constellations will only give you the neighbourhood. You'll need to find specific stars to act as your guideposts.
Image of the StarWalk app
What You’ll See
Your initial search is going to be for the "smudge." The curious object in the background that will often appear grey, milky and fuzzy behind the bright light of neighbouring stars. Once you've found what you believe is your deep-space object you can try varying increases in magnification to see if you can gather more detail.
Example of two galaxies in the Leo Trio as ‘ smudges' (Bottom right and Top left)
Artificially Improving Your View
An interesting way to truly appreciate a deep-sky object is through the use of astrophotography. Our eyes betray us. They only absorb the light that is apparent. A time-exposure on a digital camera will allow the light from deep-space object to accumulate and add texture and detail. Unfortunately, a Dobsonian without its expensive motor drive is not the best scope for time-exposures. That's where the value of refractors and reflectors come into play. The key once again is to make sure you are in a dark-sky environment.
Example of the Leo Trio with a CCD Camera by Hewholooks
The best camera approach is a digital camera with a CCD or charge-coupled device. This is the technology that allows the light to gather and accumulate. With the right equipment you can watch on your computer or the camera's view screen as the deep-space galaxy or nebula grows in detail over time.
Even if you can't afford the complex technology of a motor drive and CCD camera, just looking at an object discernible as a distant smudge in the sky can be a moving experience. Especially when you have time to think that you are actually seeing the Andromeda Galaxy or the ability to simply touch with your eyes a deep-space destination.
Take at look at this article for more tips on observing deep sky objects.
Find more on: Observing the Night Sky
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