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

RE: [Utah-astronomy] Perseids on August 12-13
by Kurt Fisher 06 Aug '07

06 Aug '07

Ann, When an observer is not directly under a meteor shower's radiant, they see less than the max zenithal hourly rate. The maximum predicated activity is a zenthal hourly rate of 100 per hour - or once every 30 seconds - if you are standing right under the shower radiant at the peak. For Utah, that will not occur. When the peak of the shower occurs, the radiant of the shower (see map) will be low in the northeast sky. The lower radiant altitude means that you will see a proportionally lower rate of meteors. I'd plan on seeing 20-30 per hour - or once every two or three minutes. This year's peak is predicted for 11:00pm on Sunday August 12 through 1:30 AM on Monday (Aug. 13 at 5:00-7:30 UTC). Radiant position maps; see the International Meteor Org site for more info http://www.imo.net/ At 11:00pm, the Perseid radiant will be low in the sky above the north-north-east horizon between Perseus and Cass near the Perseus Double Cluster. Expect to first see "grazers" - bright low meteors that enter the atomsphere nearly parallel to the ground, running northeast to southwest. As the Perseid radiant rises, its activity will be decreasing. Conversely, because the radiant is higher in the sky, you'll see more meteors. My experience at Little Mountain is these two factors balance out at around 20-30 per hour - or once every two or three minutes - with a good fireball every 10 minutes. Towards 1:00am the rate will drop off and becomes uninteresting. Little Mountain should be a good observing site this year. The radiant rises in the darkest northeast portion of the sky at that site. The light pollution from Salt Lake is in the west. You can see the Cygnus Great Drift in the eastern sky. The main problem is that 12:00-1:00am curtain call. -:) Currently, the county is putting in a new sewer up Emigration. You have to stop for 2 special construction traffic control lights - each about a 5 minute wait each - that feed through single lane road sections. Going up the back route on I-80 and East Canyon will be quicker. Conversely, the construction keeps the party crowd size down. Last Friday night - Saturday morning at Little Mtn - typically a pre-back to school party night, there were two cars and myself and little road traffic. For the last three weekends, no-see-ums have been heavy at this site even after midnight. Definitely wear DEET or other no-see-um repellant. Typically, I sit out in a lawn chair with a whole horizon sky chart. (Print from http://www.fourmilab.ch/yoursky/#Telescope ). Plot the direction of the meteors that you see on the chart. They will make a flashlight pattern pointing back to the radiant. I also set up mounted binoculars or a small scope pointed at the radiant. There are many more small meteors - not visible to the naked eye - that can be seen in the scope. It is instructive to compare the two. If you are lucky, a bright bolide or satellite will streak through the eyepiece while you are looking. At 1:30am, Mars will be at 5 1/2 degs altitude. The mountains will block it, but Mars should peek over the eastern ridgeline around 2:00am. (You'll be up anyway. So why not. -:) ) Last night, Mars was quite bright even near a third quarter Moon. - Kurt More background info: IMO Calendar http://www.imo.net/calendar/2007 search on term "Perseids" IMO Summary for the Perseids in the Calendar ================================= Maximum: August 13; 5h 7h30m UT - but see text ZHR = 100 . . . . The Perseids were one of the most exciting and dynamic meteor showers during the 1990s, with outbursts at a new primary maximum producing EZHRs of 400+ in 1991 and 1992. Rates from this peak decreased to ~ 100 -120 by the late 1990s, and in 2000, it first failed to appear. This was not unexpected, as the outbursts and the primary maximum (which was not noticed before 1988), were associated with the perihelion passage of the Perseids' parent comet 109P/Swift-Tuttle in 1992. The comet's orbital period is about 130 years, so it is now receding back into the outer Solar System, and theory predicts that such outburst rates should dwindle as the comet to Earth distance increases. However, some predictions suggested 2004 -2006 might bring a return of enhanced rates ahead of the usual maximum, and in 2004 a short, strong peak happened close to that anticipated pre-peak time. After that, activity seemed to be roughly normal in 2005, and the moonlit 2006 return was still to come when this text was prepared, but nothing untoward was predicted for 2007 in any case. An average annual shift of +0°05 in the gamma of the "old" primary peak had been deduced from 1991 -99 data, and allowing for this could give a possible recurrence time around 9h UT on August 13 . . . , if so a little after the most probable maximum, that of the "traditional" peak always previously found, which is given above. Another feature, seen only in IMO data from 1997 -99, was a tertiary peak at gamma = 140°4, the repeat time for which would be 15h UT on August 13. Observers should be aware that these predictions may not be an absolute guide to the best from the Perseids, and plan their efforts accordingly, so as not to miss out, just in case! Whatever happens, and whenever the peak or peaks fall around August 13, new Moon on August 12 creates perfect observing circumstances this year. For mid-northern latitudes, the radiant is sensibly observable from 22h -23h local time onwards, gaining altitude throughout the night. The UT morning-hour maxima suggested here would be best-viewed from across North America and northern South America, while the possible ~ 15h UT peak would fall best for Far Eastern Asia. Visual and still-imaging observers should need little encouragement to cover this stream, but telescopic and video watching near the main peak would be valuable in confirming or clarifying the possibly multiple nature of the Perseid radiant, something not detectable visually. Recent video results have shown a very simple, single radiant structure certainly. Radio data would naturally enable early confirmation, or detection, of perhaps otherwise unobserved maxima, assuming more than one takes place, if the timings or weather conditions prove unsuitable for land-based sites. The only negative aspect to the shower is the impossibility of covering it from the bulk of the southern hemisphere. End IMO excerpt ================================= _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Re: [Utah-astronomy] SLC midair collision (was Meet George Jetson)
by Chuck Hards 06 Aug '07

06 Aug '07

Research shows that it was only 20 years ago: "On Jan. 15, 1987, a Mooney M20 pilot was practicing holding patterns near the extended approach path into Salt Lake International Airport and inadvertently entered SLC's airport radar service area. Approach Control wasn't receiving an altitude read-out from the Mooney's transponder and unfortunately the practice holding pattern roughly coincided with the traffic pattern for Salt Lake City Municipal No. 2 Airport, a general aviation facility located roughly six miles to the south of SLC, thus adding further confusion as to the exact location of the Mooney. At the same time a SkyWest SA-227 Metroliner was being vectored to the final approach course for SLC, its pilots attempting to locate traffic pointed out by ATC. Despite the good weather, the Metro pilots never spotted the Mooney because the two aircraft collided over Kearns, Utah, raining aircraft parts on the residential neighborhood and killing the 10 people aboard the two aircraft but somehow avoiding any loss of life or injury to people on the ground." (Aviation Week) On 8/5/07, Chuck Hards <chuck.hards(a)gmail.com> wrote: > > Many years ago, there was a mid-air over Kearns between either a 2-or-4 > seater (for some reason I'm remembering that it was a Mooney) and a commuter > turbo-prop. > > On 8/5/07, Patrick Wiggins <paw(a)wirelessbeehive.com> wrote: > > > On 05 Aug 2007, at 13:06, Chuck Hards wrote: > > > > As I pilot who knows of a number close calls that have happened in > > the mostly wide open skies over SLC, anytime I think of the traffic > > on the I-15 corridor each evening raised high into the sky (and most > > "pilots" yacking on their cell phones), well I just can't see it > > happening with current technology. > > >

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Perseids on August 12-13
by Ann Blanchard 06 Aug '07

06 Aug '07

Are there any places in particular you would recommend for late night/early morning viewing (hopefully) of the Perseid meteors? Is Little Mountain a good choice? I ask about it because if we are staying up really late, I would like to avoid a really long drive home (Salt Lake). Monday morning at work comes way to soon and I'm not sure how much my boss would believe that I had just been out really late looking at the sky. On the weekend we are planning to go to the Gravel pit for some viewing any may see some meteors then. Have any of you heard estimates of how lively the "show" will be? I've heard tales from folks who have seen meteor storms, but I have never had that exciting experience. Ann M. Blanchard Undergraduate Studies University of Utah a.blanchard(a)ugs.utah.edu

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Cone error guru - part 2
by Kurt Fisher 05 Aug '07

05 Aug '07

Q1: I have a Ken Dauzat extra-heavy duty mounting bar (13 inch long) on order, hoping this will help with the cone error problem on the 10 inch Newt, described below. Should I change the order and make the bar 18 inch long. I feel part of the problem may be optical tube assembly flexure. Q2: Assuming that the Synta EQ6 is inherently overloaded with a 30+lb 10 inch Newt on it, and the cone error cannot be reasonably removed, what does this foretell for: 1) Pointing accuracy 2) Tracking accuracy for astrophotography. I had hoped to use the Atlas 10 inch Newt on the GEM for astrophotography. Since the cone error may not be removed, I am not so sure that it can really be used for this purpose. I can use the 5 1/4" refractor for imaging, which is also described below. Background info: After rebuilding the mounting bar, tube rings and finder holder, I was able to remove cone error down to between 15 to 30 arcsecs (less than one circle width of a Meade 12mm reticule on a 1127mm focal length) for a 5 1/4" refractor (about 20lbs) and a Synta EQ6 GEM mount. But when I tried this with the 10" Newt (30+lbs, 1200mm fl), it was apparent the cone error could not be removed, even using the solid mounting bar (Scopestuff LD75 bar). Just mounting the scope and weights and rolling the scope from the 6h to 18h positions, resulted in the polar finder flopping about 10 arcmins (1/2 the width of the cross-hairs (that are about 20arcmins) in an Orion Altas polar scope reticule). At the 6h to 18h positions, the centered alignment target was moving 3/4 to 1 deg. I tried to remove the cone error, but in the end it seemed to be fools errand. So, I compromised and removed the cone error to a 90-60 arcsecond tolerance - just using the 3h and 21h RA positions instead of 6h and 18h. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Meet George Jetson
by Chuck Hards 05 Aug '07

05 Aug '07

http://news.aol.com/story/_a/company-now-sells-real-flying-saucers/20070803… This looks remarkably like the saucer that a fellow in North Salt Lake was developing a decade or two ago, I wonder if the projects are related? I'm rather partial to rotary engines as some of you know, so this caught my eye- until I read the 40-gallon-per-hour fuel consumption rate! And rotaries (even the small ones) must use high-octane fuel to prevent pre-detonation, which can blow out the spark plugs and apex seals (that's instant total power loss in a rotary engine). That's $120+ per hour to operate, at best! I think the time of the flying saucer is still a ways off, though the military, search-and-rescue, and science may find it usefull. The small airship is still much more ecconomical however, and has a smaller environmental footprint.

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SLAS/OAS/UVAA Star-B-Que/Swap meet Aug.18
by Chuck Hards 05 Aug '07

05 Aug '07

If attending, is there a co-ordinator for the food, or are folks just bringing whatever for a true "pot-luck"? What will the policy be if the general public shows-up before the star-party itself? I'm trying to either talk my girls into attending or just coming solo. We'll see.

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Re: [Utah-astronomy] Meet George Jetson
by sjseebergp＠webtv.net 05 Aug '07

05 Aug '07

Suggested reading...Avrocar Canada`s Flying Saucer. About a jointly-manned Canadian USAF project during the early 1950`s. The testing results are experienced up to todays technologies. Jan

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Go Phoenix, go!
by Patrick Wiggins 04 Aug '07

04 Aug '07

Phoenix just launched to Mars. Everything looks fine. pw

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Mobile Phones
by erikhansen＠TheBlueZone.net 04 Aug '07

04 Aug '07

Hi All, I know this is a liittle of topic, anyone have good or bad expreinces with T-Mobile. I have been checking out their "the only phone you need" service. Seems like a good deal, but only if it is about as relaible as my current land line. Thanks, Erik

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Re: [Utah-astronomy] Exciting new adventure for PAW and Fuy ( & others?)
by Gary Vardon 04 Aug '07

04 Aug '07

I'd volunteer but it seems too tame. just kiddin. -----Original Message----- From: Ken Harris Sent: Friday, August 3, 2007 8:53 PM To: Utah Astronomy Subject: [Utah-astronomy] Exciting new adventure for PAW and Fuy ( & others?) Hey Y'all, Just saw this awesome article in the June 2007 issue of "Popular Mechanics" (if you can't find it at the store, try your local library). Seems some (maniac) entrepenuer and his partner are trying to develop a thermal-rated pressure suit that will allow people (crazies) to free-fall from 60 miles in space. They'll get to that height aboard a privately-run open-cockpit rocket that will then fall back and be recovered behind them somewhere. This "ultimate extreme-sport diver will reach a speed of 2500 mph before entering heavy air at around 100,000 ft altitude, and then make a normal parachute landing some 10 minutes after bailing out at +/- 300,000 ft. Sounds like fun! Any takers? Ken ----- Original Message ----- From: "Chuck Hards" <chuck.hards(a)gmail.com> To: "Utah Astronomy" <utah-astronomy(a)mailman.xmission.com> Sent: Friday, August 03, 2007 5:53 PM Subject: Re: [Utah-astronomy] Telescope generators (was: Mobile Phones) > You're right, Joe, if your generator isnt connected to the house wiring, > you > don't need the transfer switch. > > Unfortunately, furnaces don't plug into the wall- they are hard-wired. > Thus > the transfer switch. It's also difficult to reach the refrigerator plug > in > many instances, without moving a heavy fridge. > > If you use an under-rated extension cord(s), you risk overheating the > cord. > > You won't harm the power system if you accidentally energize the grid, > though you could damage your generator. The concern is that you could > electrocute a Rocky Mtn. Power technician if he's working on a line that > he > thinks isn't energized. > > > On 8/3/07, Joe Bauman <bau(a)desnews.com> wrote: >> >> If you intend to hook individual appliances to your generator, such as >> via >> power strip, I suspect you don't need a fancy switch. Couldn't you have a >> light, TV and furnace or some such combination, on a power strip that is >> connected only to the generator? I don't understand how that could harm >> the power system. When the electricity is restored, just unhook these >> items from the power strip and plug them into the household current >> again. >> Or am I missing something? Thanks, Joe >> > _______________________________________________ > 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 _______________________________________________ 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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