March 2008 - Utah-Astronomy - mailman.xmission.com

Re: [Utah-astronomy] Spring 2008 Rainbow Hunting Calendar - SaltLake City
by Canopus56 03 Mar '08

03 Mar '08

Ivo - >From this listpost, I was hoping to drum up a couple of Utah and/or Salt Lake rainbow photos to add to the page. > Do you or other list members have suggestions of > a favorite location to view/photograph rainbows > from, in the Salt Lake Valley? I don't think it's a matter of location; it's a matter of having a prepared mind during a favorable time window and keeping a camera handy. Topography plays a role - on the Wasatch Front that seems to favor spring. Personally, I've always seen them when standing or driving along 11th Avenue above the cemetry or for many years, when I was working on the 15th floor on the south side of a downtown office building. But, that is just where I live and work. Once you understand the geometry involved, I'm sure there are many other locations throughout Salt Lake, Davis and Utah counties that are just as good, for example your west bench Herriman description. I got started on this after deciding I wanted to capture some of these spring rainbows with a camera. > I was not as clear on the specifics . . . > particularly with regard to the formation > of secondary rainbows. The secondary rainbows are at 52 degrees. In Salt Lake, I've only noticed them (and their reversed order spectra) during a near sunset scenario, when a near full 42 degree (80 degree arc) rainbow is also visible. Typically in April or early May. > Wikipedia has a good article . . . including a > ray diagram of the double reflection . . . Looks like I need to revise the webdoc. The first draft said, "one refraction and two reflections." Then I settled on "three refractions". Which terminology is right? > I thought if I were asked to explain it to > a school class or other group I might find > myself . . . stammering quite a bit . . . > Thanks for including the Descartes figure. I'm still unclear on how a side angle view works in three dimensions. Most frequently, I see rainbows when standing to the northwest of the rainbows' apparent position, which isn't what Descartes' figure shows. Glad you enjoyed the webdoc. Mothers with children under 8 seem to really get excited about this one for some reason. Guess it's something cool to do with the kids outdoors. - Kurt ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs

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Synta mount owners - ASCOM driver update to version 5.0
by Canopus56 03 Mar '08

03 Mar '08

A week ago, I posted about the Synta firmware 3.21 update for club Orion Atlas/Synta mount owners. http://www.skywatchertelescope.net/swtinc/customer_support.php?id=91&class1… It appears this Synta handcontroller update should be installed after the installing a new major edition of the ASCOM open source telescope driver software. The current ASCOM is now version 5.0. http://ascom-standards.org/ If you have the existing version 4.0 ASCOM drivers, do not remove them. The upgrade is built on the existing install. You'll also need to install newer ASCOM drivers for your scope. For the Synta/Orion Atlas mount, that's the Celestron driver. http://ascom-standards.org/Downloads/ScopeDrivers.htm There are now specific upgrade drivers for the LX200 classic with Autostar I controller and the new LX200 GPS model. The LX200 drivers are exclusionary. You can install only one or the other, but not both. (Since I ocassionally work with either and the drivers install in seconds, a dropped a copy of both driver install files into my "mount tracking" directory. Either can be installed as needed in a few moments.) I have not fully tested the new ASCOM v5.0 drivers. However, under Cartes du Ciel and Astroplanner, I can enter the scope configuration menus and they both show the version 5 interface. Time to get your mount ready for the new season! The Skyscan v3.21 handcontroller software may not need to be updated from v.3.20. I updated mine just to get it out of the way. The main change is to provide the option to utilize direct drive control between a laptop and a Synta mount. However, direct drive requires wiring modifications to the controller board - something few people are going to do. See the Skywatcher post in the EQ6 newsgroup dated Mar 1 2008 at 2:07 titled "[EQ6] Re: Upgrading Question V3.21" for more details. - Kurt ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping

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USA 193 fragment Monday evening
by Patrick Wiggins 03 Mar '08

03 Mar '08

CalSky is predicting a possible reentry of a piece of USA 193 for the evening of Monday 3 March 2008. Here are particulars calculated for SPOC: Rise 21h48m14s --.-mag az:322.6° NW Culmination 21h51m26s --.-mag az: 48.5° NE h:52.9° distance: 200.0km height above Earth: 161.9km elevation of sun: -39° Set 21h54m38s --.-m az:134.3° SE The object will be in shadow so it will only be visible if it reenters. patrick

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Spring 2008 Rainbow Hunting Calendar - Salt Lake City
by Canopus56 02 Mar '08

02 Mar '08

Spring 2008 Rainbow Hunting Calendar - Salt Lake City - March to May http://members.csolutions.net/fisherka/astronote/plan/rainbowhunt/RainbowHu… Printable rainbow calendar graphic http://members.csolutions.net/fisherka/astronote/plan/rainbowhunt/img/Rainb… The spring is a good time for rainbow hunting in Salt Lake City because of the interaction between weather and the Wasatch Mountains. Rain storms come from the west off the Pacific Ocean and are blocked by and pile up against the north-south trending Wasatch Mountains. This creates a band of light rain sheets along the east bench of the Salt Lake Valley. The western sky can be partly cloudy or clear, while the eastern sky is under a cloud deck. When the Sun is low in the southwest sky, the Sun streams under the eastern cloud deck and strikes rain sheets. These are favorable conditions for the formation of rainbows. The website and graphic calendar lists favorable times when rainbows might be seen in Salt Lake City during the prime spring months of March, April and May. The webpage is suitable for scout groups and school children and includes a SafeSurf pics rating code. Although not applicable to other areas of the country, it suggests how similar a rainbow hunt calendar can be generated by local astronomy clubs, particularized for their region. - Kurt ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

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Obs Rep. - Little Mtn Pass 3-1-2008 midnight
by Canopus56 02 Mar '08

02 Mar '08

At Little Mtn Pass, Saturday, 3-1-2008 midnight to 2:00am (before the storm on Saturday afternoon came in). The sky was cloudless and the temperature was a very tolerable 41-45 degrees. Light intermittant breeze picked up at 1:30am and made setting up a larger scope inadviseable. Extinction was moderate to heavy. Exceptionally good views of Saturn just past opposition. Rings at a low angle. Mars also still bright. Spent a couple of hours with a small refractor during basic start-of-season sky reviews. The Leo-Virgo Realm of the Galaxies was overhead but the small refractor did not have enough apeture to work galaxies. Mostly posting to report that the night temperatures were workable. - Kurt ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs

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For club Synta EQ6 mount owners - a latitude bolt modification - locking
by Canopus56 29 Feb '08

29 Feb '08

These photos show a simple modification to a Synta EQ 6 scope to lock the latitude bolts more firmly. A fly nut and a rubber washer lock the bolt with respect to the mount housing. http://gallery.utahastronomy.com/main.php?g2_itemId=11021 http://gallery.utahastronomy.com/main.php?g2_itemId=11024 The latitude bolts can drift on repeated scope slewing. Additionally, this modification is useful for aligning a scope for daytime observing of Mercury and Venus. The scope is aligned at night, marking the tripod feet locations, and then set up the next day during daylight for solar and day planetary observing. The scope can be fixed in latitude, dismantled and set up close to the polar alignment (in latitude), the next day. White out marks on the mark base can also record the setup location of the mount in azimuth. - Kurt ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping

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