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Cold, cloudy, and confusing – but that’s OK ;-)

Double-star learning opportunity handout – to be read before observing session – and/or after.Download file

Double-star field notes document with stars suitable for fall to early winter. Download file

Well, I'm learning. I'm learning that my expectations for youth between the ages of 9 and 12 – and for adults – are out of sync with reality. So last night's session with the Webelo Scouts from New Bedford was very instructive for me – and I think they got something out of it as well. But it was a long way from what I envisioned it would be and what I had planned so carefully.

What I believe went right was having a specific observing task and a prepared observation reporting form. They all seemed to get into the assignment of drawing each double star and reporting the colors on their field notes sheet. (A PDF version of this is linked at the start of this entry.) Having a meaningful observing task and bringing some discipline to the observing by asking key questions, is essential – and a continuing challenge to develop.

But more important form my perspective is what went wrong.

There were two issues. First, finding a specific star in the telescope is much harder than I thought, even when they know the basics. (That is, these folks had had an indoor introductory session about telescope use and knew enough to point one at the moon or a bright planet. But a star is much different. )

Second, the task of seeing what they are expected to see and comprehending it – especially when using high powered eyepieces - is challenge enough at this stage (third learning opportunity for this group under the stars).

The next time this group is out I want to focus on open star clusters, but I need to really think about exactly what I will do about this, In some ways the clusters will be easier for them to find, so maybe I should have done them before double stars.

Aha! The flaw in my reasoning. I am not putting the observing challenge first and I need to. It had seemed to me there was a logical progression from double stars to star clusters. IN an abstract, lesson plan way that's true. But when I replay the tape in my mind from last night what I see is too eager Scouts, both familiar with the Orion 4.5-inch Dob and both being able to find Albireo with the naked eye, struggling terribly to find it in the telescope. Why?

Because when you point the little Dob towards Albireo – especially in the skies we had with relatively poor transparency and lousy seeing – and you look in the little optical finder, you suddenly see half a dozen stars or more and you don't know which one is Albireo. I know. Any experienced amateur would. But for the beginner the differences in brightness don't jump out at them and that's the only real clue. They've gone from a sky with a single star in it, to a sky with many stars revealed by the finder.

Solution? Either don't give them the task, or give them a scope with a one-power finder - a Telrad or red dot type.

Next time out they will be looking for M35, 36, 37, and 38. Here the optical finder is a better choice. Sure, you can use a Telrad , or something similar, and star hop. The Telrad with its concentric circles is good for this task. But an optical finder will show them the cluster target as at least a blur. When they see it, they will know what to point at, if they have been properly prepared. But for a double star that can be seen with the naked eye, the one-power finder is the way to go.

Needless to say, life would be easier if I had several six-inch Dobs. Even though I've focused on having telescopes that are easy to use, the mish-mash is a challenge and the two scopes that are easiest to use are the 4.5-inch Dob and the 6-inch refractor which is on a simple Dob-like mount. If I were equipping this program from scratch and money were not an issue, I would purchase four, six-inch Dobs and probably complement their optical finders with a one-power finder.

But moving to the other problem – knowing what you are looking at and looking through a high-powered eyepiece. There are a couple of obvious solutions to the high-powered eyepiece problem – one is to use a low powered eyepiece and Barlow it – that keeps the eye-relief at what they are used to. My standards have been the 25mm and 10mm Plossls. Adding the Barlow – and encouraging its use with the 25mm makes sense, though this may not be quite enough power to do the job. The other obvious solution is to use eyepieces with high eye relief and therefore accommodate eyeglass wearers as well.

Bottom line – I find that both youth and adults simply have problems getting used to looking through any eyepiece. Some are easier - and generally they are the ones with more eye relief – but too much eye relief can lead to confusion as to just where to hold your head. So I don't see a simple fix. I'll continue to do what I'm doing – ask people to move their heads around until they see the image. This does suggest one thing, however:

Start a group of sessions – and maybe each session – with a bright object and tell them to get used to using the eyepieces. I don't run into this problem of "I don't see anything" when they're looking at a bright planet, the moon, or even a very bright star.

As to knowing what they are looking at, this comes with experience – but it's helpful, I think, to frame the subject properly by carefully choosing the eyepiece. So maybe what I need to do is frame the subject well and have them look at it first with one of the "go to" telescopes. Then have them find the subject on their own? To avoid having that take away the fun and excitement of discovery, perhaps I should do this with only one object of a particular class – one double star, one galaxy, one nebulae, one star cluster – whatever.

Actually, this suggests a general pattern I may be able to apply to most sessions:

1. Introduce 1-3 constellations. Point them out quickly with green laser – then hand out appropriate charts, Ask them to study and scan vicinity with binoculars for anything that looks interesting.
2. As they're busy with naked eye and binoculars take one at a time to one of the "go-to" scopes and have them look at a sample of the type of object they're assigned to observe that night. When each is done, send them to a telescope to find, observe, and make notes or drawings of the object as instructed.,
3. Keep the two "go to" scopes pointed at the dimmest – or most difficult – examples of objects to be observed that night. Have each take a turn at these scopes near the end of the session.

I'll use that as a general plan for my open cluster session which is next on the agenda.

Posted by Greg Stone at November 26, 2005 01:14 PM Comments? Please email me:

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