The best part of owning a telescope is being able to view in detail some of the most beautiful astronomical objects in the night sky. Without first taking time to learn how to use your instrument effectively and where to point it, however, the experience is likely to prove a frustrating one. Learning more about the objects you intend to view is also a must in order to derive the most benefit from your stargazing hobby. After all, it may be easy to glance at the Moon or Jupiter’s rings, but do you really know what you are looking at?
Personal Stargazing Plan
The first rule of stargazing – never go out thinking that you will be able to see everything there is of interest in the night sky on any given night. Sure, sometimes you’ll catch a glance of some amazing stuff like double stars, asteroids, occultations, and variable stars, but most of the times, you will be limited to observing whatever is visible given the time of year and general viewing conditions. A good approach to stargazing is therefore to make some kind of plan of what it is you want to see before settling down to your night’s viewing.
Finding Space Objects
The easiest way to find astronomical objects is by consulting an astronomy catalog, and while there are quite a few of them about (Caldwell, Herschel 400, New General, etc), the most popular and easiest to use is Messier’s List of Astronomical Objects. All of the 110 space objects listed in the catalogue have coordinates, expressed in declination, right ascension, and the constellation that they belong to. An astronomer can subsequently use these coordinates to easily pinpoint their location, and although this may take a little while to get the hang of, be assured that it gets easier with practice.
Meanwhile, telescopes with a motorized mount and a space object database are able to locate these space objects at the touch of a button, and automatically track them as they slowly move across the sky. For more information on mounts, star tracking, or how to set up your first computerized telescope, you should definitely check out a specialized website.
Analyzing Space Objects
Once you are able to find your favorite space objects, you can start analyzing and understanding what it is that you are seeing. Let’s talk about two types of astronomical objects in particular that you may want to turn your telescope towards during your celestial explorations, namely star clusters and nebulae.
Basically, an open cluster is a tightly-knit group of stars that have approximately the same age and origin. There are roughly 1,100 open clusters in our galaxy, the most popular of which includes the Pleiades, Hyades, Alpha Persei Cluster, and the Wild Duck Cluster.
Morphology should be an important consideration when observing an open cluster, including how concentrated or detached the cluster is, and its general spatial distribution. Brightness is very important, too, and when looking through your telescope, try to figure out how bright or nebulous the stars are in relation to the rest of the cluster.
As you probably know, a nebula is an interstellar cloud that consists of ionized gases, dust, hydrogen, and helium. Some of the most popular nebulae visible from Earth are the Pillars of Creation in the Eagle Nebula, and the Horsehead Nebula. Bear in mind, however, that all nebulae appear very different, and these differences can subsequently impact the quality of your observations. According to science, there are many types of nebulae:
• Emission nebulae are areas of space packed with clouds of hot gas. They will appear as red because they emit a high quantity of hydrogen, with a prime example being the Great Orion Nebula (M42).
• Reflection nebulae are basically gigantic clouds of dust which happen to reflect the light emitted by nearby stars. They will appear as blue, with perhaps the best known example being the reflected light surrounding the stars in the Pleiades.
• Dark nebulae are very similar to reflection nebulae in terms of consistency and light-reflecting properties, the only difference between them being how they ‘bend’ light. These may appear as dark red through the telescope, a famous example of which is the Horsehead nebula situated just south of Alnitak, the star furthest east on Orion’s Belt.
• Planetary nebulae are among the most interesting space objects. Planetary nebulae are what you might call empty shells of gas, which are discarded by dying stars, and might look like tiny planets when seen through the telescope. A good example of this object is the Medusa Nebula (Abell 21) in Gemini.
As you can see, there is more to stargazing than just buying a telescope and randomly checking out a few stars or planets through your new optical equipment. To really appreciate the beauty and depth that this absorbing pastime has to offer, it’s therefore best to first learn how to pinpoint your astronomical objects of choice, and discover a little bit more about the science behind those objects that you intend to view.