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Canyonlands star party Sept 18
by Seth Jarvis 02 Sep '15

02 Sep '15

Canyonlands Nation Park has recently received the International Dark Sky Association's highest ranking as a "Gold-Tier International Dark Sky Park." http://kuer.org/post/canyonlands-becomes-dark-sky-park http://darksky.org/canyonlands-national-park-named-international-dark-sky-p… I'll be in Canyonlands on September 18th helping them celebrate and participating in a star party with park staff and their telescopes. We still could use a couple of other telescopes. The star party itself will be at Grand View Point (N38.312 W109.857) within Canyonlands NP. I've posted about this previously, but my Utah-Astronomy inbox archive somehow vanished and I don't recall who said they'd be willing to come down. Canyonlands is offering to reserve (a very rare thing) two campsites near the star party for use by participants who come with a telescope and share the views with the public. Canyonlands staff say they're anticipating ~200 people, hence the need for more telescopes. If you're interested, or if you've previously told me you're coming, please send me a message so I know if any folks here will be coming down and wanting one of the two reserved camp sites. Thanks, Seth Jarvis Clark Planetarium sjarvis(a)slco.org

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Rides to/from starparties
by D P Pierce 01 Sep '15

01 Sep '15

Hi, I need a ride home from the Wheeler Farm SP Friday night. I can get there by bus but not home. My usual ride, my sister will be out of town. Enid will give me a ride to Advanced Training, although someone will need to load my wheelchair into her chariot. (she has neck and shoulder problems and can't lift much. I also need a ride to and from SPOC on Saturday. I live at 6200 S and Bangerter. My 40 lb. wheelchair folds up and fit in truck beds, hatchbacks and in some backseats. Deloy Pierce Large Bored Member

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Fw: Making a 36" from many smaller mirrors
by daniel turner 27 Aug '15

27 Aug '15

----- Forwarded Message ----- From: daniel turner <outwest112(a)yahoo.com> To: Siegfried Jachmann <siegfried(a)jachmann.org> Sent: Thursday, August 27, 2015 12:56 PM Subject: Re: [Utah-astronomy] Making a 36" from many smaller mirrors To make the Keck work they needed dozens of electric motors that would bend the cell to realign the mirrors every time the telescope was moved in elevation. It took a long time to develop and troubleshoot the computer system that controls all those motors and alignment sensors. This would be beyond the abilities of amateurs to perfect. Another way would be to build a mirror cell stiff enough to hold the mirrors in place against gravity. The best material to do this would be a giant piece of glass. Only glass is stiff enough and strong enough. Of course then you would be gluing your mirrors to a giant piece of glass. So why not just grind and figure the big piece of glass? DT From: Siegfried Jachmann <siegfried(a)jachmann.org> To: daniel turner <outwest112(a)yahoo.com>; Utah Astronomy <utah-astronomy(a)mailman.xmission.com> Sent: Thursday, August 27, 2015 10:48 AM Subject: Re: [Utah-astronomy] Making a 36" from many smaller mirrors Yes but, the Keck telescopes are multiple mirror telescopes. Multiple mirror telescopes do work. Future space telescopes, including the James Webb and the proposed 12 meter, are designed to multiple mirror telescopes. It's not just the weight and sagging. It's the accuracy with which they must be aligned. Typically mirrors must be no worse that 1/4 wave from ideal. That also applies to multiple mirror scopes. SJ On Thu, Aug 27, 2015 at 9:36 AM, daniel turner via Utah-Astronomy <utah-astronomy(a)mailman.xmission.com> wrote: The figure of the mirror is held in place by the stiffness of the glass. With multiple mirrors you need a massive mirror cell or dynamic motors to constantly fight against the sag from gravity. In space it is easier because gravity is taken out of the equation. There was a professional telescope called the MMT which was arranged in a six gun fashion. But that was just to have something to do until the big onepiece of glass was ground, figured, and polished. So there is no real advantage in the long run. DT From: Jay inUT <jayleads(a)gmail.com> To: Utah Astronomy <utah-astronomy(a)mailman.xmission.com> Sent: Wednesday, August 26, 2015 6:58 PM Subject: [Utah-astronomy] Making a 36" from many smaller mirrors Ok, I got approached by my boss at work about the possibility of making a 36" mirror for observing from say several 8 inch mirrors (think an arrangement like James Webb). In thinking about this to me it seems that there are issues here about positioning the mirrors and ensuring that once ground, they form a parabola etc. So what are the thoughts on this? Can an amateur make a large mirror from smaller mirrors and what would it take? Just curious and I know what my reply was but I said I would inquire. -- Thanks! Jay _______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Send messages to the list to Utah-Astronomy(a)mailman.xmission.com The Utah-Astronomy mailing list is not affiliated with any astronomy club. To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options". _______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Send messages to the list to Utah-Astronomy(a)mailman.xmission.com The Utah-Astronomy mailing list is not affiliated with any astronomy club. To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options". -- Siegfried

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Neat sunspots today
by John M. Craig 25 Aug '15

25 Aug '15

Hi Folks, Last week a good set of prominences, today (and yesterday--sorry didn't get it posted) there's a couple of complex sunspot groups that are the main attractions. In Ha light, you can see that they're interacting with each other (yesterday, it looked like almost classic bar-magnet lines between the two groups: arched lines in the chromosphere plasma between the two groups). I also saw one of the groups throw off a couple of flares yesterday. I haven't tried looking in white light, but I imagine they'd be interesting that way also. John

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Pretty spectacular prominences today
by John M. Craig 24 Aug '15

24 Aug '15

Hi Folks, Although the smoke's pretty obvious here in N Utah, H-a light comes through with remarkable clarity. There's some pretty great prominences today. If you have the gear and the daylight time, enjoy! If you'd like to have a look through my scope (I'm in Orem), you can contact me off the list. Ciao, John

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NEO 2010 AL30 passage
by Brent Watson 22 Aug '15

22 Aug '15

Patrick, That is a very nice animation of thee passage of NEO 2010 AL30 you got on EPOD today. Congratulations! Brent

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Eclipse weather
by Wiggins Patrick 22 Aug '15

22 Aug '15

Yesterday (the 21st) marked two years until the 2017 total eclipse of the Sun. As I've done the past couple of years I downloaded a satellite image taken at the time of day when the eclipse will be happening and added it to the montage of my two previous years' shots. Here's the result: https://www.facebook.com/groups/SLAS.Talk/

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SLAS meeting info
by Chuck Hards 21 Aug '15

21 Aug '15

Somebody posted a link to a map to the free parking area at SLCC recently. Is that link still active, and can someone repost it? I looked on the SLAS website but didn't see it. Hope to see you there tonight, come hear Mike talk about his big scope!

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Re: [Utah-astronomy] Pretty spectacular prominences today
by Mark Shelton 20 Aug '15

20 Aug '15

Thank you Craig for the notice. The sun was spectacular from woodland. Very nice prominences. 3 great ones. Thanks again Mark Sent from my iPhone > On Aug 20, 2015, at 11:25 AM, John M. Craig <jmcraig(a)xmission.com> wrote: > > This message has no content.

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Smoke-Haze vs Star Party
by Bruce Hugo 20 Aug '15

20 Aug '15

Anyone tried observing through this smokey haze? Just curious if we'll be able to see anything this weekend at the star party(s). Especially with the moon providing illumination. Clear skies (seriously!)Bruce Hugo

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