Tag Archives: Understanding

Finishing the Herschel I program

In the fall of 2012 I bought my first telescope since having one as a kid. I wasn't sure how much use I'd get out of it but I wanted to give it a go. I suspected I'd not regret the purchase. Within the first couple of weeks I'd become obsessed. I went out each clear night and sometimes stayed up till I started dozing at the scope which was often in the wee hours of the morning. Within a couple weeks I'd started keeping track of the objects I was viewing. I started just with the date, object name/ID, date and time. Soon after I started noting the eyepiece I was using as well as a description. It occurred to me that it would be fun to do the full Messier list and get the certificate from the Astronomical League. Not that I cared all that much about the recognition but having a list helps give a bit of order to the process. Had I not taken it on I might have gotten stuck looking at the same objects. Another side effect of having a list and doing the "official" program is the requirement that the observer find the objects on their own. No go-to telescopes allowed. Which was not as much of an issue as I didn't have a go-to telescope. But reading about the program drew my attention to the idea of systematic searching and recording.

A month into the Messier list I realized there were some nights that when I would have no objects to search for as I would have already found all the available objects on the list that were up in the sky. So it occurred to me to look for another list that I could start at which point I became aware of all the various programs that the Astronomical League administers. I settled on the Herschel I and got started. It's a list of 400 objects from the NGC catalog of 7,840 objects, largely based on the observations of William Herschel, his son John and his sister Caroline. It's a mix of galaxies, star clusters and various kinds of nebulae. It's a great list to do after the Messier list because it is slightly more difficult with fainter objects.

I finished up, or thought I did, about a year later. Upon checking my list though I discovered that I'd bungled a few by not recording proper descriptions and I was also missing a few. So, I started filling in my gaps until, about a year later, I thought I was finished. And, again, I discovered a few I had missed! So, back to it. With each successive check my list of missed objects was getting smaller. Essentially my transition from the initial list to spreadsheet to database introduced a few errors. Over the past couple of months I've been taking care of the few remaining objects and in the wee hours of a late September morning I finally got the last object in my eyepiece. NGC 2372, a planetary nebula in Gemini. I entered it in to my report and spent the rest of the morning double checking my final list. All in all the list took about four years and during that time I recorded well over 500 observations for that particular list (many duplicates due to the first 100 or so having been recorded without the detailed descriptions).

What did I learn during the experience? I learned much more about seeing the objects. Early on I was moving too quickly from one object to the next. It was not uncommon for me to log 15 objects in a 4 or 5 hour session. That's three to four an hour. When you consider the time it takes to find an object in the scope and record the observation it turns out I was only looking at some objects for 5 minutes or so. That's a minimal amount of time. These days I tend to look at about half that number of objects and I spend more time on each one.

The process of really seeing a faint object requires dark adapted eyes (no bright lights after you start viewing. Only low levels of red light!) and it requires at least 10-15 minutes, often times more, for each object. I also find it helpful and more educational if I take some time reading about the object. I don't necessarily see the object better but reading about it helps me appreciate what I'm seeing. It's easy to do using Sky Safari which is my preferred astronomy app. Each object has a description associated with it, many of them are quite detailed. There are also images in the app which can be very helpful in finding some of the details that might otherwise be missed.

I also was also reminded that there is an important connection between observation, vocabulary and description. As with any skilled observation it is important to develop an understanding of the components of what is being viewed. For example, if I'm viewing birds I pay attention to not just the colors but also the shape of the beak and tail, the physical habits, the body shape, the song, etc. There are many details that will help me identify the species of bird I'm looking at as well as understand something about the bird for example it's diet or food gathering habits. The same might be said of plants, trees, butterflies or any other observation of the natural world including astronomical objects. There is a certain literacy that goes with observation and increased literacy means a more detailed interpretation of the sensory data.

When I first began looking at galaxies I mostly just saw smudges of light. But right off it was evident that the shapes varied. For example, the Andromeda Galaxy (M31) and it's two neighbor galaxies (M32, M110) vary quite a bit in size, shape, brightness and features. They're a good starting point and learning tool. M31, a spiral galaxy, fills even the largest wide-field eyepiece with its large disc and offers a concentrated, bright nucleus as well as dust lanes. By comparison, M32, an elliptical galaxy, appears as a compact and bright nucleus with no disc. M110 is also an elliptical galaxy but is much larger than M32 and better described as an oblong nebulosity with a slightly bright central area but no bright core or nucleus. But while these three nearby galaxies are a good starting point and each offer different characteristics to be described they are just the beginning of many galaxies. Then there are the many kinds of nebulae and star clusters to learn about. No doubt astronomy offers many years of possible observation, a lifetime of possibilities in fact.

So, where to next? I've already started three other programs: double stars, nebulae, and the Herschel II list. I think I'm going to start the lunar program as well. As our closest neighbor the moon can cause a great deal of light pollution for much of each month making other observations difficult. But it's a fascinating subject itself, why not enjoy it?!

Looking at other galaxies

One of the best things about living under really dark skies and having a decent telescope is viewing other galaxies. While I equally enjoy the many beautiful objects in our own galaxy such as nebulae and globular clusters, the hunt for distant galaxies has a meditative quality for me. Sometimes the finding is a bit of a let down. For example, last night I went looking for NGC 7042, a spiral galaxy. It took some doing but I found it. It’s 250 million light years away. Yeah. It was the faintest little smudge of light barely detectable on a very clear night with a decently sized telescope (12.5 inches). When I find these really faint ones I always laugh at my disappointment. Yes, it is a galaxy filled with billions of stars and yes, I just sighed in disappointment. But, but, it’s 250 million light years away I remind myself. Not only that it is moving away from us at 5,083 kilometers per second or, 1.7% the speed of light. There will come a time in the distant future when that galaxy and others are no longer visible from Earth. The stretched out light will no longer reach us. The Universe is expanding and that expansion is accelerating. Eventually galaxies that are currently visible to us will blink out. Of course, by that time we’ll likely not be here to notice.

The thing about viewing other galaxies is that it helps frame the scale of the Universe. When I look at the star Vega I’m seeing a star that is only 25 light years away. Yes, still a vast distance from our perspective. But it’s in our local neighborhood so to speak. In fact, it’s like a neighbor on our own street. Funny thing, the stars we see when we look up without a telescope are all in our local neighborhood. We’re only seeing about 6,000 of the very closest stars in our galaxy of 200 billion stars. When I look at the Orion Nebula I’m looking at something that is only 1,400 light years away. Sure, that’s a good bit further than Vega but again, remember that our Milky Way galaxy is an average of 100,000 light years in diameter. So, Orion is still very much in our local neighborhood.

The Andromeda Galaxy is the largest galaxy of the Local Group which consists of about 45 other galaxies including our Milky Way.

The Andromeda Galaxy is the largest galaxy of the Local Group which consists of about 45 other galaxies including our Milky Way.

But back to the viewing of galaxies, the easiest to view from the Northern hemisphere of Earth is Andromeda which is “only” 2.5 million light years away. It fills the eyepiece of my telescope and can actually be seen with the naked eye if you’re under dark skies. I have no problem picking it out from the stars of the Milky Way. It’s oval of faint light is actually quite large and fills an area larger than the full moon in our night sky. It’s quite close and in fact, billions of years in the future we will in fact merge with Andromeda. I viewed Andromeda just two nights ago. I also viewed the Bode’s galaxy, M81 and the Cigar Galaxy, M82 which are a pair of galaxies 12 million light years away and are fairly bright and easy to find with a telescope. In 2014 a star went supernova in M82 and we were able to view it from Earth. Quite a show! So the pair is, in the larger scale of things, quite close. A bit further than Andromeda but not nearly as far as the 250 million light years that makes NGC 7042 so faint.

Faint and distant or bright and close, viewing other galaxies is a thrill because it means looking at the starlight of hundreds of billions stars. As those photons stream into my eyes I’ve got a direct connection with the ancient starlight created by billions of suns. It is light that has been stretching through the Cosmos for millions of years and ends its journey in my eye. The experience is one which enhances my perspective and gives life on Earth an added dimension. In seeing such distant worlds I begin to contemplate and understand the scale of the Universe in a way I had not before. It has changed who I am as a human as well as my understanding of what it means to be human.