AC Tries to Learn a Little Astronomy

We have an observatory very near us at the Mill of Kintail, to which I have frequently referred . Every year, the astronomers associated with the observatory put on a series of workshops in both spring and fall. I have always been interested in attending but usually haven't noticed that the classes were being offered until after they have begun. This year, I did notice in time and signed up for the five sessions. I looked forward to the opportunity of making even a small dent in my ignorance of the night sky, for I feel some shame in not being able to recognize anything other than The Big Dipper.

Unfortunately, the telescope in the observatory is being refurbished, so all classes have been held in a nearby building. Well, I take it that they usually are held in said building but that at least one session or part of it normally occurs at the observatory. As my luck in life continues to hold, such was not to be the case for this session of lectures.

On the plus side, the instructor does bring her telescope, which is of fairly impressive size. When the weather permits, she puts it up in the parking lot and points out various visions in the night sky. On the first night, for example, I was able to see, Mizar, the second star in the handle of The Big Dipper (Ursa Major). It is actually part of a double or binary star and is quite a pretty sight.

This led to another unfortunately, however, as three of the fours sessions that have occurred so far have been held under skies which were obscured. Therefore, very little star actual gazing has occurred. Friday will mark the fifth and final lesson; hopefully, we'll get to star gaze for a change.

Much of the lecture material is scientific and a little overwhelming to my old, dull brain, but some things do sink in. One thing that I have appreciated is learning or re-learning about the size it all. A little over forty years ago, at the beginning of a physical geography course, I taught a little about our galaxy and solar system. What I learned and taught then has been reinforced, particularly about our galaxy: The Milky Way.

We have christened our whole galaxy The Milky Way from the belt of stars that we commonly refer to as The Milky Way when we look up at the night sky. There are so many stars that the belt that we're all so familiar with seems milky in appearance. While that belt is part of the larger galaxy, it is not to be confused with the whole galaxy. Indeed, what we commonly refer to as The Milky Way when we are looking up is only a relatively small part of our disc-shaped, spiral-armed galaxy.

I hope I am making that point clear as it can be confusing. There is The Milky Way that we see, but it is only a part of the whole Milk Way galaxy.

As the diagram shows (look for the sun on the left) our solar system sits on one of the galaxy's spiral arms, an estimated 28 000 light years from the galactic centre. There is a huge mass of stars in the centre bulge, but we don't even see them as far as I able to understand. The part that we see and refer to as the Milky Way is thought to actually be the next spiral arm that is closer to the centre of the galaxy. It is closer to the galactic centre than is our sun, but it is not the actual Central Bulge.

I had more to say, but since this has taken more words than I had thought, I think I will post this as is for now. Perhaps I will continue in days to come. Please hold your applause until then.