December 27, 2008
November 30, 2008
Archives - this blog has moved
I have decided to put all my blog entries on all subjects in a single place. However, you can find all new - after October, 2008 - astronomy blog entries here.
The home page for all my current blog entries is here.
Thanks for visiting. My apologies for the inconvenience.
September 23, 2008
Love - who understands it?
Looking at giant Rigel this morning - 40,000 times brighter than our Sun - I found myself pondering two questions:
1. Why do I love double stars so?
2. And why do I love this little 80mm Orion Eon telescope so much more than it's larger cousin, the 100mm Orion ED ?
I think the second question is a bit easier, so I'll tackle it first. It has nothing to do with optical quality. Both yield pristine images. But mechanical quality and sheer good looks? The Eon has the 100 ED beat by a mile. The Eon looks like an Alpha Romeo next to the 100 ED's work-a-day, American Motors appearance.
Yikes! I hate myself for saying that! I can hardly believe I would write such a thing. I am the guy who would always defend the hard-working, no frills, spare-me-the-lipstick approach. Yet I have to admit I have three small refractors - the other is an Astro-Tech 66 - and of the three the 80mm Eon is my first choice, edging out the Astro-Tech 66 only because it gathers a bit more light. The practical part of me will choose the 100 ED when I think the objects I want to see are a bit too challenging for the smaller scopes - but when I do, the romance goes out of the experience.
But there's something else at work here and I think it has to do with relationships. See, me and the 100 ED got off to a bad start because in purchasing it - used on AstroMart - I did so against my better judgment. I was going for simplicity and optical quality, but the previous owner had added a motorized focuser to the scope which he insisted I would love. I was definitely in KISS mode, but I let his sales pitch get the better of me and bought it. Well, the auto focus never worked. I don't think the owner lied. I simply think it got damaged in transit, though that wasn't obvious to me at first. But it set up some bad blood that I started taking out on the scope. Unfair? Of course. But relationships are complex things. That was more than a year ago and despite the wonderful images delivered by the 100 ED, I simply can't warm up to it.
And I admit - the polished mechancal slickness - with mechancal fine focusing - of the other two scopes appeals to me. The fine focusing part is logical - but I never thought I'd care about the finish on a telescope tube. Hey - the whole idea is to use a scope in the DARK. What's important is not what the scope looks like, but what it is like to look through - what sort of images it delivers.
And about those images - they're terrific. Especially with planets, the moon, and double stars - although where I notice them most is with double stars. Planets and the moon still don't excite me that much - too familiar, too close to home. Galaxies are fun, but they're so far away, so faint, so huge that the numbers defy any attempt at comprehension. Star clusters are great - but again, the numbers tend to overwhelm.
But turn the scope towards Castor and I find something my little mind can manage - barely. i did that this morning after first spending some time with the last quarter moon. I had the 80mm Eon in the Observatory mounted on the "go to" mount that's meant for the Celestron 8 SE. A simple "solar system align" had put me in business quickly and the moon was right smack in the middle of Gemini, so asking the computer with this ridiculously simple , one-object alignment to find Castor was no stretch. It did and tracking was good and steady.
Castor split easily at about 75 power, but I was really much happier with the 175X view provided by a Hyperion 3.5mm eyepiece. What it shows you is three stars - two bright ones very close together and a third member of the system that is much fainter and well off to one side. I've seen it many times, but I never tire of the view and I think the reason is that in a universe where the size and distance of things so often overwhelms us, Castor is much easier to contemplate and begin to grasp.
I say "begin" because Castor is really six stars. We see one with the naked eye - three in the telescope - but each of these stars has a hidden companion, detectable by spectroscope. Frankly, I don't dwell on that. What I do in my meditative moments, however, is try to imagine myself on a spacecraft - or planet, near one of these Suns and how my sky might look from such a vantage point.
And this whole complex system is but 50 light years away - so the light I'm seeing now left Castor when I was about 17. That's manageable. I can almost imagine being 17. Much easier than trying to grasp the view of the Andromeda Galaxy I had the other night. Never mind that the light from that object had been travelling more than 2 million years to get here - as I looked at the galaxy I knew the light from one side of it had left those stars about 150,000 years before the light reaching me from the other side of it. I can write that sentence. But 150,000 years is way beyond my experiential understanding - let alone the 36 million years for the journey from another galaxy I was viewing earlier that same evening.
So I come back to my doubles, sip my tea, and meditate. And after spending about half an hour with Castor et al, I realize that another old favorite, Rigel, is now in view. (See, I have to wait for the trees to move and for Rigel to come into my due-south gap. ) At this point the sky was getting lighter in the east and that might actually have helped me split this challenging star. Rigel is big and bright. To our eyes, about as bright as Castor - but the light from Rigel started it's journey to Driftway Observatory roughly around the time the nobles were holding John's toes to the fire until he signed the Magna Carter. That's a mental construct for me - not an experience. But hey - 800 years, i can extrapolate from experience and have some grasp that. (Ok - you ant to get technical. The Hipparcos' “best guess” for Rige;s distance is 773 light-years ), with a margin of error of about 19%.)
But it's just plain fun to be able to "split" this double because there is such a large difference in brightness that the faint companion star gets lost in the glare of Rigel. The companion is almost bright enough tobe visible to thenaked eye if it were off by itself somewhere - but that still puts it more than 500 times fainter than Rigel!)
And speaking of that glare - no, I can't really come to grips with the idea of a star that is 40,000 times as bright as our Sun. Hmmmmm.... wonder how far away the Earth would be to make it habitable if it were orbiting Rigel? And how long would an orbit take? How long would a single year be? But you see - those sorts of questions are within my grasp. I can play with them.
But aside fom this rational approach, there is just the simple aesthetic beauty of the two stars, close together - and the closeness invites easy and subtle comparisons of brightness and color.
And in the final analysis, my relationship with double stars probably is no more rational than my relationships with different observing instruments. i just know I love 'em.