May 2007 - Utah-Astronomy - mailman.xmission.com

Variable Sun?
by Kim 17 May '07

17 May '07

Note: The following is NOT a discussion of global warming but of historic evidence for a variable Sun. So, please no one take offense. For my money, the best thing on television is the History Channel. I've seen some interesting episodes that described climatic conditions in historic times that may or may not be linked to variations in the Sun's energy. For example, during the Roman period, Europe appears to have been quite warmer than it is today, with vineyards producing wines in Brittania (England) that today can only be produced further south, in France and Italy. It is also appears that the Dark Ages coincided with a much cooler period. The resulting climatic and economic stresses seem to have contributed to the political chaos of the times. What is not well know is whether there were other forces besides the Sun's energy output that might have played a more important role. (Maybe the internal-combustion-engine-driven chariots of the Romans caused their warmer climate.) For example, some argue that the colder climate of the Dark Ages was caused by aerosols in the atmosphere from volcanic activity, and not due to the Sun at all. While the Maunder Minimum is well-documented, it seems that we just don't have enough hard data to categorically link the Sun to all climate change - at least that's what the History Channel says, and as everyone knows, TV is always right. In many ways we live in fascinating times. I doubt that the Romans, Gauls, Visigoths, Vandals, Byzantines or others in earlier times even had the means to know if the Sun were changing, and here we have the tools to measure even the most miniscule of changes. Does anyone know of reliable observations of changes in the Sun's output that might have been made by earlier cultures, that is, other than the Maunder Minimum? Kim

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RE: [Utah-astronomy] Private Star Parties
by Debbie 17 May '07

17 May '07

It does not look good for Friday, but how about Saturday night? It's a little too hot here down in St George. I could use some cooler weather and dark skies up north. http://cleardarksky.com/c/SpnsFkUTkey.html?1 How far is is Mount Pleasant from St George? I have to be back by 1:30pm Sunday afternoon. Debbie On Thu May 17 15:04 , 'Kim' <kimharch(a)cut.net> sent: >As a matter of fact, there is a great site about 4 miles away - the backyard >of the house we rented for two years. I just spoke with the owner, and he >would allow us to use the yard and the bathroom in the house (it isn't yet >occupied). The house is near the mountains, so the eastern horizon is >elevated a bit, but not too much so. You can see a photo that I took of the >Milky way shortly after we moved to get a sense of how dark the skies are: >http://www.utahastronomy.com/Kim/Sagittarius_Milky_Way_1_001. The yard is >large and should accommodate a dozen or so scopes. Only problem is there is >no tent camping, but there is a generous gravel area for parking a trailer >and we are welcome to throw a sleeping bag on the ground if we need to >crash. The owner also requested that there be no consumption of alcoholic >beverages, nude dancing around the campfire, burning man (or woman) rituals, >and that we generally behave ourselves. The elevation is about 6500 feet, so >it can get cold, but it is rarely windy. The house isn't heated, but at >least we could get in out of the cold to warm up if needed. Power is also >available for anyone who needs it. I offered to pay for the use of the >place, but the owner said it would probably be OK without paying anything. >Let me know. > >Another possibility is an elevated site (maybe a hundred feet or so) on a >small hilltop, also nearby. Seeing may be better there, but there are no >amenities. I think there would also be room for a dozen scopes. The access >road is a bit steep and probably not suitable for trailers. If you wish, >I'll check into using that site. > >Anyone have a handle on the weather forecast for this weekend? > >Kim > >-----Original Message----- >From: utah-astronomy-bounces+kimharch=cut.net(a)mailman.xmission.com >[mailto:utah-astronomy-bounces+kimharch=cut.net@mailman.xmission.com] On >Behalf Of Don J. Colton >Sent: Thursday, May 17, 2007 1:56 PM >To: 'Utah Astronomy' >Subject: RE: [Utah-astronomy] Private Star Parties > >Do you have a site that is close to your house several of us could come >to. The Wedge is quite a bit farther and Skyline would probably be >pretty cold. It would be nice to get a good dark eastern horizon. > > >_______________________________________________ >Utah-Astronomy mailing list >Utah-Astronomy(a)mailman.xmission.com >http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy >Visit the Photo Gallery: http://www.utahastronomy.com

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Star party in Provo Canyon (South Fork) tomorrow (Friday) night
by Richard Tenney 17 May '07

17 May '07

Just as a reminder, I will be doing a star party in Provo Canyon (South Fork) Friday night for a bunch of local 6th-graders; anyone who wants to get out and help would be very welcome (expecting about 60 kids). If you can help out, directions can be found here: http://www.uvaa.org/cgi-bin/conf.dll/topic?&tid=9D1FF733508F I'm planning on setting up the 16-inch about 8:30. I understand John and Lisa Zeigler will also be there with their 12.5" f/8 dob. Weather is supposed to cooperate last I checked. TIA, Rich ____________________________________________________________________________________Give spam the boot. Take control with tough spam protection in the all-new Yahoo! Mail Beta. http://advision.webevents.yahoo.com/mailbeta/newmail_html.html

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RE: [Utah-astronomy] Solar Caused Global Warming
by Michael Carnes 17 May '07

17 May '07

Amen to that. >I respectfully recommend that we all voluntarily refrain from using this >forum for posting articles and opinions on global warming. The internet >offers zillions of other places to do that. >

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New scope owner help proposal for 5/25 or 5/26 star party
by Kurt Fisher 17 May '07

17 May '07

This is to suggest that for the 5/25 or 5/26 star parties that SLAS advertise it as a "bring your new Christmas scope" or "my new Christmas scope is collecting dust" star party. We would have a designated new scope user area and people on hand to help new users through the process of getting their scopes setup and/or DSC's running. It would probably take two SLAS members willing to leave their scopes at home to run the area. Some sort of power strip via an extension cord would be needed. Since I'm the proponent, I'll put my hat in. My preference would be for the 5/25 urban-Harmon's party, leaving the 5/26 star party so I can enjoy my scope. However, Bill Kennedy is doing a "telescope basics" presentation on 5/26, so maybe the idea would fit in better there. Just an idea for discussion, either for the 26th or another star party later in the year. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Re: [Utah-astronomy] Meade LX200 - How to use with a DSI?
by Kurt Fisher 16 May '07

16 May '07

Daniel wrote: > When I say "generous" that may be an > understatement. . . . . It also means that > focus can be achieved at any distance behind > the primary all the way to infinity, . . . Thanks, so there is no theoretical limit. Chuck wrote: > The reason for a short-coupled camera is usually > lack of swing-through room on a fork mount. So the backfocus limit is a physical interference constraint. Thanks for the heads up on that one. I would not want to break a focuser tube off! Daniel wrote: > The drawback is the slow focal ratio which grows > with the backfocus. Although the light-weight easy-to-handle SCT package size is a big plus, one of the more confusing things to me about buying an SCT is their owners shell out for a scope with a 3000mm focal length and then immediately turn-around and spend another $200 for an adapter to turn it back into an 1100mm f/l Newt. I'll try to physically measure the backfocus and report back. Now if I can just find my ruler marked "infinitiy", "generous", "doesn't fit", "right-on", "adequate", "too small" and millimeters. -:) - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Re: [Utah-astronomy] Meade LX200 - How to use with a DSI?
by daniel turner 16 May '07

16 May '07

There are lots of issues that need to be addressed for astrophotography. So much so that those who are actually doing it are usually way to busy to offer advice. But as far as backfocus on a SC? Fahgettaboutit! DT ____________________________________________________________________________________Need a vacation? Get great deals to amazing places on Yahoo! Travel. http://travel.yahoo.com/

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Meade LX200 - How to use with a DSI?
by daniel turner 16 May '07

16 May '07

When I say "generous" that may be an understatement. You see with a refractor or a newtonian the focal length is fixed and the backfocus is constrained to a certain distance from the primary optics. With the SC the focal length is VARIABLE and depends stongly on the distance between the primary and secondary. This is how focus is achieved. It also means that focus can be achieved at any distance behind the primary all the way to infinity, which is why the SC is ideal for the astroimaging. The drawback is the slow focal ratio which grows with the backfocus. That's why I sugested a focal reducer. DT ____________________________________________________________________________________Pinpoint customers who are looking for what you sell. http://searchmarketing.yahoo.com/

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Meade LX200 - How to use with a DSI?
by daniel turner 16 May '07

16 May '07

The SC is generous with back focus. This is because the focal length and focal ratio are variable. Just undo the mirror lock (if it has one) and turn the main focus nob to get in the ballpark and fine focus with the autofocus after locking the mirror again. The DSI is not a Planet camera so I assume you are going after deep sky objects. If so you may want to add a focal reducer to increase your field of view and shorten exposure time. DT ____________________________________________________________________________________ The fish are biting. Get more visitors on your site using Yahoo! Search Marketing. http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php

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Meade LX200 - How to use with a DSI?
by Kurt Fisher 16 May '07

16 May '07

Daniel wrote: > The SC is generous with back focus. ... > Just undo the mirror lock (if it has one) > and turn the main focus nob to get in the > ballpark and fine focus with the autofocus > after locking the mirror again. Thanks, Daniel, I'll give it a look-see. The LX200GPS manual shows a primary mirror lock knob. The LX200 manual does not show one. Any idea how far the backfocus is in terms of inches or mm? - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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