Wednesday, October 29, 2008

A Requiem for Charlotte

There are more things that come out at night than just the stars.
For the past six months, we've been treated to the goings on in an arachnid's world. A small spider had taken up residency in our doorway. She was very methodical; at sunset, she'd come out and setup her web, and before sunrise (usually), she'd have it removed. Her web just occupied a corner but covered a span of perhaps 450mm. She was thorough and neat.
Within a few weeks of her setting up shop in our doorway, she simply kept the heavier threads up and would remove the intricate inner silk, and we let her. She was earning her keep. We named her Charlotte for obvious reasons.
In time, she ceased retreating into her cranny as we came up and simply sat in the center of her web, occasionally shaking it. Even then, it was just a couple of shakes, and then she'd go about her business. It was almost an arachnid wave; "hello, mammalian bipeds!"
In her own way, she was beautiful, with markings rather reminiscent of a grey tabby cat (not unlike my own Lexi, in fact). These were the markings Nature gave her for her role as a predator. Predators in nature are not evil; they serve a very important place. Spiders, no matter how frightening or repugnant they may seem to some, are remarkable. I will admit, they have startled me whenever I've come across a large one in an awkward place, but soon I am simply admiring them.
Orb spinners, like Charlotte, are very common, but she was uncommon. She seemed to have developed a relationship that was mutually beneficial.
Unfortunately, small spiders do not have long lives, and we had no idea how old she was when she made a home in our doorway, though she was clearly an adult, if a young one. As the weather began to cool, she began to slow down. I knew that with the first chills of October she was having a hard time. Her webs were shrinking, her movements slowing. Several nights, she would simply not come out.
This morning, as I was heading out for work, I glimpsed up. She was hanging out of her nook. One of her rear legs was extended. I blew on her once, but she did not move.
She was gone.
I waited until I returned home to remove her. By that time, she had fallen out of her web altogether, and was laying on the doorstep. I carefully picked up her body. I've never cried over an invertebrate, but for her, I got choked up.

One of the things that saddens me is that I never took a photograph of her web when it was in its glory, with her perched in the center. But I at least wanted to remember her, even if in the somewhat macabre death photo above.
She was magnificent, and I will honestly miss her.
Ad astra per somnium, dear Charlotte.

Wednesday, October 22, 2008

Telescopes as a Measure of Maturity?

Whilst researching some small telescope designs (an obsession of mine, mind you), I keep coming up with a trend on Google that actually bothers me; too often, it seems, online retailers refer to small telescopes as "children's". This doesn't seem to apply to many of the better made brands (Orion, Meade, Celestron) but to off brands, bordering on "department store" quality (which can vary wildly; the term is at best a misnomer). Some of these off brands, though, are actually made by the same companies (almost all of which are located in China) that make similar instruments for the big names. Just a simple comparison of some of these "children's" models reveals their similarities to their better named kin.
That's the crux of a bigger problem. Our society has unusual views of hobbies that are of the scientific bent, as they are almost always seen as the realm of young people. Admittedly, there was a time in my youth when many, if not most, of my friends had hobbies such as electronics, bird watching, model rocketry and yes astronomy, but today, these hobbies seem quaint. Young people today, it seems, are more interested in computer games, music (nothing wrong with that, admittedly) and sports (again, not necessarily bad) than more intellectual pursuits. Hobbies that lean towards the educational are looked down upon, if not derided, in popular society. The outcast, the loner, is often times portrayed as having hobbies like that; the so-called "nerd". Younger children are many times persuaded into these hobbies to help them learn (given today’s amount of homework, though, I wonder how they can find time), but by the time they become teenagers, the risk of being teased (or worse, outcast) makes them put these things aside.
By labeling these smaller telescopes as "children's", could it be that we are implying that they will best be enjoyed by youngsters or nerdy teenagers? Talk about a marketing strategy that is bound to fail. If these retailers would take the time to examine these products a bit more thoroughly they might find that labeling them as something bordering on "toys" is a bad tactic. It certainly seems to imply a real lack of understanding about the subject, if not a severe lack of interest.

Tuesday, October 21, 2008

Serious Work With Very Small Telescopes

I've been giving a lot of thought lately to what the smallest practical size for a telescope can be. The Rev. TW Webb, in his seminal work "Celestial Objects for Common Telescopes”, made mention of a rather small telescope with a tiny aperture that he used for very basic observing. It must also be remembered that Galileo's first telescopes were very small (as was the one used by Giovanni Battista Hodierna for his deep sky observing). While many amateurs shirk at the idea of anything smaller than a 4"/100mm being used for serious observing, it should be remember that many beginners do not have the sort of money that sort of instrument almost always costs.
If a beginner has graduated from binoculars but still lacks the funds to purchase a larger instrument, a typical 60mm would probably suffice. However, I am curious to see what can be done with even smaller instruments. The first telescope I did any serious observing with was a Tasco 50mm, and was able to make out many of the brighter Messier objects. What I am curious to see, though, is what can be seen with a 35mm or 40mm instrument.
40mm telescopes are actually out there. Meade sold a nice one that was available through Wal-Mart for a while. Let me qualify that; the main objective was nice, the rest was somewhat questionable; the diagonal in mine had a second surface mirror, the eyepieces were cheap .965" units, the interior of the OTA was left in bare aluminum and the tripod was a little tabletop unit that was basically useless. However, most amateur astronomers have the parts to overcome these, if not the skill.
What you can expect to see with a small telescope in this range would not be too different from the view afforded one through binoculars. There are numerous books out there dedicated to binocular stargazing that can readily cater to the small telescope user. Under good observing conditions (magnitude 5.5), a 40mm at a modest 20 power can see down to magnitude 10.5, well within the range of many deep sky objects. While resolution might not be great, for basic, lightweight stargazing, it is perfectly suitable.
At this time, I've limited most of my work with my Meade 40mm (named "Vic") to studies into Galileo's and Hodierna's observations. However, I think I might just try some actual observing with this tiny instrument.

Monday, October 06, 2008

Of Telescope Mounts and Magnification

Ask any serious amateur astronomer and they will tell you that the best type of mount for any telescope is an equatorial one, and for good reason. An equatorial mount allows you to track once you have your item centered. Not only that, but they actually make the task of finding the object easier by means of setting circles. This is crucial for distant, faint objects. However, are they truly necessary if you are going after wide swaths of sky at lower power?

Probably not.
Nothing truly illustrates this better than my 114mm short tube Newtonian "Felix". This small scope has a focal length of just 500mm, an RFT or rich field telescope. Its primary mount is an equatorial, but it is used mainly as a "sweeper", looking for faint fuzzies (it has a very old fashioned equatorial mount at that, one that does not allow the scope to be rotated. That little feature causes problems quite a bit). Does this telescope really need this mount for what it's used for? No. To be honest, equatorial mounts for low power telescopes are actually more of a hindrance than help with low power/wide field telescopes. Unless you are taking images, they are probably completely unnecessary.

Where, than, shall we set the threshold for mounts?
For my purposes, low power is anything less than 40 power (and I seldom exceed that). For most, though, the threshold might be as low as 30. Once you go past your upon threshold, an equatorial mount would probably be a better choice. Based upon my own experiences, I use the following criteria to determine which mount to use.

Alt/Az - "Sky sweeping", open clusters, stellar associations, nearby double/multiple stars, nearby galaxies, some lunar
Equatorial - Planets, lunar, double/multiple star, variable star, distant galaxies, globular clusters, distant open clusters

I prefer altitude/azimuth for a variety of reasons beyond the purely technical, though. They are much simpler and therefore require less setup time (which in the field makes a big difference). It might be harder to locate fainter, more distant objects, but with a little trial and error these can be located by starhopping. There are times, though, when an equatorial trumps these and is simply required.

For the casual reader, though, the choice of mount really depends upon a number of factors, many of them simply personal choice. I think that, really, is what matters most.