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Posts Made By: jess tauber

March 5, 2007 08:20 PM Forum: Refractors

New 'ideal' antireflection coating developed

Posted By jess tauber
See http://www.sciencedaily.com/releases/2007/03/070302082821.htm

RI 1.O5, reflection strongly or completely eliminated at all angles/all wavelengths (claimed). Made from silica nanorods.

Dunno conditions of deposition, durability of coating just from reading the piece above.

Jess Tauber

March 28, 2007 04:52 AM Forum: Solar System Observing

Hex wrench, anyone?

Posted By jess tauber
Apparently old news, but Saturn has a polar hexagon. What the hey? Here is video: http://www.space.com/php/video/player.php?video_id=070327Saturn_hexagon

So if I had a wrench big enough, and place big enough to steady myself...(apologies to Archimedes, I think, though it coulda been some other Ancient).

Was out looking at Saturn tonight, but didn't see it. But then I don't have a space probe.

Jess Tauber

April 2, 2007 12:26 AM Forum: Politics

Ahminedejad dies in freak radiation mishap

Posted By jess tauber
Fumble-fingers! grin

Jess Tauber
(April Fool)

April 2, 2007 12:37 AM Forum: Telescope Making

My 36 inch hotdog cooker

Posted By jess tauber
Sure I'm foolin', but only to a certain degree....

I recently purchased, for almost nothing, an old 36 inch security mirror. It's plastic, rather easily bent, and has obvious surface distortions on the second surface side where the mirroring is. That and its focal ratio of something like 2 make it problematical as a beginning of a working telescope. So far I've polished away about 5 percent of the otherwise rather brittle backing to avoid its taking the mirroring with it, as if that would help grin . Then I'll try to determine the actual focal ratio.

Even if this cannot produce nice focused images on stars, I'm hoping it can do SOMETHING other than cook my dinner. For instance enough light concentration to do spectrograms on stars? Or would the smearing together from different source prevent that?

Jess Tauber
ever hopeful

April 7, 2007 07:33 PM Forum: Telescope Making

smoothness of a floated surface?

Posted By jess tauber
Hi- my issue here isn't with 'figure' but with smoothness produced when a material solidifies on top of a liquid, as with industrially made 'float glass'. Is this interface very smooth, or are there micro irregularities? Also does such a surface end up with waves or ripples at different size scales?

Jess Tauber

April 23, 2007 02:45 AM Forum: Solar System Observing

Did Herschel see Uranus' ring in 1789????

Posted By jess tauber
See http://news.bbc.co.uk/2/hi/science/nature/6569849.stm

If true this is very neat indeed. With industrial and light pollution, its amazing that we can see our little toes these days, let alone the sky.

Jess Tauber

May 3, 2007 12:54 AM Forum: Telescope Making

4 inch secondary for folded scope

Posted By jess tauber
I just purchased from a fellow Amarter a 4 in. minor axis secondary mirror to experiment with. I want to try folding a Celestron CR6 into an 'L'. The mirror has a cemented 45 degree flange with a mounting hole and screw in it. This was obviously ok when attached to an original diameter-crossing 'spider' in a reflector, but may need some sort of intervening element for the folded refractor to leave space for the glass. I don't want to remove it.

I might want to get some sort of mount with micrometer adjustments, or build one, for use with this. I'm open to suggestions.

Jess Tauber

May 10, 2007 07:30 PM Forum: Solar System Observing

Over or under- Io on Jupiter last night?

Posted By jess tauber
Here in New Jersey around 3:40? last night I was able to watch Io as it headed in towards Jupiter. My magnification was too low to tell if the moon passed in front of or behind the planet. Can someone tell me?

It was the first time I'd observed such a thing happening in real time- over a period of about an hour I looked back every ten minutes or so.

Jess Tauber

May 15, 2007 06:35 AM Forum: Deep Sky Observing

FINALLY Dagnabbit!#@$%&

Posted By jess tauber
In between cloud banks rolling through I managed about an hour ago to catch M13, nearly at zenith, and get some resolution, using my Coulter 10 inch Dob and better ep's (including a 32 and 20mm Celestron Erfles, a 12mm UO Ortho, and a nice 3x barlow I got at the latest NEAF).

The view was the best in two years I've had the dob, actually able to resolve festoons/loops of stars, maybe 200 or more? Previously I'd only been able to see hints of resolution, and the Hardin 8 in StarHoc I've been using for low power views didn't cut it, even with the ep's above.

OK, NOW I'm impressed. Aperture Fever hits- with a dash of longer focal length desire.

Jess Tauber

May 23, 2007 02:01 AM Forum: Telescope Making

Long throw cassegrain spherical?

Posted By jess tauber
Hi to some of the folks 8)

I'm curious to know whether it is relatively easy to grind/polish long FL cassegrain primaries, where I'm ASSUMING that if long enough the primary can be spherical. Or does the secondary throw a monkey wrench into this idea? I'm thinking F20 or thereabouts.

Obviously less glass removed, less work, but also there is the cored center to consider. So, will this work, or will the image suffer too much from not having the primary parabolic?

Jess Tauber

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