Wednesday, October 3, 2018

Getting to know the sky


At our public star parties a number of people have never seen the impressive objects we usually show through a telescope ask about how, and at what cost they could acquire a telescope to look at the stars, planets, the Moon, and other objects in the sky.

My long-time come-back to this question for people who are new to looking at the sky through one of our members' or SFU's Trottier observatory's telescopes are questions of my own. I ask whether they own a pair of binoculars. If the answer is yes, then the my next question is: have you ever looked at stars through them? Many people have never even thought of doing this. To those people who have done it, I put this question: would you know where to look for the Andromeda galaxy (or some other object in the sky)? The answer many times is "no".

With the apps available on computers, tablets, smartphones, etc., many people compare the sky portrayed on these devices with the sky visible at the time. That's a legitimate approach, but, in my opinion, if one comes to rely on these devices, one usually does not "learn" the sky.

I grew up at a time when these devices were "science fiction". Having had an interest in astronomy since I was eight years old, knowing the sky is an "innate" feeling for me, at least as far as the northern hemisphere is concerned. I've not much time closer to the equator, therefore I don't have the same familiarity with the southern sky.

In my younger years I did some serious astronomy, for instance submitting observations to the AAVSO (American Association of Variable Star Observers) regarding variable stars, Z├╝rich sunspot numbers, occultation timing, and other things. These activities, and many others are now done by both amateur and professional astronomers (the two categories really overlap nowadays, since the technologies available are now highly sophisticated and not very expensive), and generate very precise and detailed results.

At this time in my life, my greatest enjoyment comes from our public star parties. I get a kick out of comments like "wow", "cool", "amazing" when people are looking through one of my telescopes at the sky. In particular, I feel very happy when a young person comes up with these comments.

Adults who are "newly exposed" are equally amazed. The objects which usually are the source of this are the "jewels" of the sky: Venus and its phases, Jupiter and its moons, Saturn's rings, our Moon's craters, open and globular star clusters, etc.

Here are the recommendations I usually make:

(1) When outdoors, preferably under a dark sky, use only your eyes to get to know the sky and constellations using one of the star finders we hand out freely on various occasions, or find a printed or on-line star atlas. Familiarize yourself with the constellations and their annual positions at various times of the year. Dig deeper, and become knowledgeable about the Earth's orbit and how that relates to these times of visibility. Try to find objects which our unaided eyes can readily perceive (Pleiades, Hyades, Milky Way, compact constellations, etc.). If you feel that you'd like to see these targets in more detail, then

(2) use your binoculars to find these objects. If you are a young person, 7x50 binoculars are ideal. Your age and personal preferences have an effect on what may be your perfect binoculars. Almost all binoculars will show far more detail in the night sky than the "naked" human eye. Using binoculars will "train" you to find sky objects. At first you may spend some time to succeed, but you quite quickly become better at it.

Many very descriptive dissertations have been written about the use of binoculars in astronomy. Even advanced astronomers, at least those who are involved in the visual observing, have their favorite binoculars on hand when observing. Personally, when I'm setting up one of my telescopes, I always have binoculars with me. They are very helpful in locating objects for which I want to use the telescope. Once you have become familiar with their use and characteristics, and if you are looking for even more detail, a telescope may be your next "step up".

(3) Before you buy a telescope, understand the basic requirements. Beside the size of your contemplated purchase, understand differences between the various types. This is a much-discussed and written-about subject. The best way to find out is to attend star parties, such as the ones run by the RASC, or SFU's Trottier Observatory, because you will usually meet people who are using different types of telescopes. You will also become aware of the fact that purchasing a telescope entails having to buy a sturdy, and accurately manufactured telescope mount. The best telescope is next to useless unless it can be held steady, and does not shake with every little breeze. The matching of telescope to its support is another important topic.

Computerized telescopes are a helpful addition to the range of telescopes available. Again, unless you have learned how to find objects in the sky as described in (1), (2), and (3), you likely won't get to know the sky in the detail necessary. Getting to know the sky "in depth" is best done by learning to point a telescope "manually".

If you become a member of the RASC, you'll have access to many benefits. As a member, you can borrow one of the RASC's library books, and/or a loaner telescope for a limited time. You also receive several publications, chief of which is the RASC's annually published Observers' Handbook. It contains a wealth of data, among which you'll find detailed information about binoculars, telescopes, human eyes, and upcoming monthly events (eclipses, occultations, planetary positions - a plethora of facts and discoveries). The Handbook is used by professional and amateur astronomers world-wide. The RASC also owns the magazine "Skynews", and publishes the RASC Bulletin and local RASC centre newsletters. All these are included in the membership.

Try it - I think you'll like it.