April 2011 - Utah-Astronomy - mailman.xmission.com

Question about SCT mounting threads
by Patrick Wiggins 02 Apr '11

02 Apr '11

Are the threads used for attaching accessories on the back of Meade SCTs the same as those used on C-8s? Thanks, patrick

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C8/Meade threads
by Stephen Peterson 02 Apr '11

02 Apr '11

The threads on my C5 were inter-changeable with the Meade 8 SCT. C8 is likely to be the same Steve

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Endeavour Looking Up
by Patrick Wiggins 02 Apr '11

02 Apr '11

I rather liked today's APOD: http://apod.nasa.gov/apod/ap110402.html Reminds me of the "T+30 and Flying Again" posters from years back: http://www.shopgoodwill.com/auctions/T-Plus-30--Flying-Again-DISCOVERY-PRIN… I'd love to see a shuttle stack go by from that vantage point. 'Course it would probably be the last thing I ever saw <g> ). patrick

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Re: [Utah-astronomy] 2" Laser Collimator
by Canopus56 02 Apr '11

02 Apr '11

Howie Glatters Holographics Collimators http://www.collimator.com/coltext.htm (They ain't cheap.) Clear Skies - Kurt

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Re: [Utah-astronomy] 2" Laser Collimator
by Canopus56 02 Apr '11

02 Apr '11

Mark wrote: > WOW, Yes they look very sturdy and well made. The Collimator comes > with a very big price also. Do you have one of these and > do they work good? Yes, I own one, Glatter's holographic collimators are the best and his collimator works exceptionally well. The ``holographic'' part means that there is an extra lens that spreads out the laser beam into a circle just smaller than 2 inches. That disk reflects off the angle bottom of Glatter's collimator. With a cheaper single point laser, it is possible to misalign your mirror, since the reflected point may land on the center of the secondary mirror, but the entire primary and secondary are at an angle to the centerline. Glatter's design collimates both the primary and secondary in three dimensional planes. Expensive laser collimaters like Glatter's are not needed for visual observing. They can add a little bit to your high magnification planetary visual observing but will not do anything substantial for your visual DSO observing. Laser collimators are really used for astrophotography, where you are trying to get the most resolution out of your camera chip when using a small fast focal ratio DOB. For visual observing alone, a little cap pinhole collimator is fine, even for short focal ratio DOBs. The 30 USD single point collimators are not really worth the money in terms of relative improvement in visual observing - IMHO. Others may have different opinions. A simple test that illustrates the ineffectiveness of a low-end single point collimator is to put the laser collimator the focuser. Do a collimation. Now loosen the focuser screw. Look anyway from the scope, but your hand on the collimator and randomnly rotate a number of turns. Re-secure the focuser screw and test your collimation again. You will find that the laser point will now be significantly at a different position and your scope appears to be quite a bit ``out of collimation.'' Glatter pays close attention to fabricating a finely machined, true collimator barrel that nearly, but not completely self-centers itself. (The device comes with some rubber gasket rings that help to true center the collimator in the focuser barrel.) If you do the same laser point beam test with Glatter's collimator (by removing the ``holographic'' beam spreading lens), the pinpoint laser dot will also move, but only by a very small amount. Clear Skies - Kurt

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2" Laser Collimator
by Mark Shelton 02 Apr '11

02 Apr '11

Hi all, I am looking at purchasing a 2" Laser Collimator for the Dob I am making. Please let me know what brand and model that you think is a good model to purchase. Or if you have one you would like to sell or ? to a new DOB. I had the opportunity to watch 2 versions at work last night, (Pit-N-Pole) Each one had options I liked. Let me know what you think Mark

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Saturn at opposition Sun April 3
by Canopus56 01 Apr '11

01 Apr '11

``Saturn (magnitude +0.4, in Virgo) comes to opposition on the night of April 3rd.'' - S&T Weekly Sky at a Glance - Planetary Roundup. Clear Skies, Kurt

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Re: [Utah-astronomy] Pit n Pole Thursday
by Jay Eads 01 Apr '11

01 Apr '11

Oh, I should mention, I drive a black Nissan Pathfinder and I park in the outer parking lot just west of the Holiday/Chevron but in the Walmart Parking lot area. On 2011-03-31 13:08, Jay Eads wrote: > There will be several people out at Pit n Pole both tonight, Thursday and > again on Friday. This will include visual observers and those doing > astro-photography. Humidity was very high at Pit n Pole last night, in the > 90% range for a majority of the night. Tonight the forecast is for lower > humidity, around 65% until 2:00a.m. and then climbing to around 80% after > that. So if you plan on staying late I'd have some dew heaters ready to > go. Nothing new for this site. If you want to avoid the humidity you could > observe up on Five Mile Pass which is up out of the muck but doesn't have as > much of a open view but the skies above 25 to 30 degrees are just as good > (and who looks under 25 degrees right?). > > I am meeting a friend at Walmart at 5:30p.m. in Lehi at the corner of Hwy 68 > and Hwy 73. We'll leave right at 5:30p.m. as we want to set up in the light > and be ready go before it gets dark. > >

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Star Party at Great Basin National Park
by Kelly_Carroll＠nps.gov 01 Apr '11

01 Apr '11

Howdy all, I just wanted to announce the next Star Party at Great Basin National Park. It will be Saturday, April 23 in celebration of Jr. Ranger Day. We will start in the afternoon with solar observing, followed by an evening of observing under the clear dark skies of the park. Moonrise is not until about 1:00AM. As always, we ask the support of the astronomer's in the region. Thank you for all you do. Hope to see you here! Best, Kelly Kelly Carroll Great Basin National Park http://www.nps.gov/grba/ Experience your America

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