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

Re: [Utah-astronomy] One for you glp afficiendos
by Kurt Fisher 30 Oct '07

30 Oct '07

Thanks, Joe. I missed your articles. - Kurt Contest seeking elevator to space By Joe Bauman Deseret Morning News Published: Monday, Oct. 22, 2007 12:23 a.m. MDT http://deseretnews.com/article/1,5143,695220777,00.html 'Space' climber almost By Joe Bauman Deseret Morning News Published: Tuesday, Oct. 23, 2007 12:21 a.m. MDT http://deseretnews.com/article/1,5143,695221108,00.html _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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One for you glp afficiendos
by Kurt Fisher 29 Oct '07

29 Oct '07

On the last night of an extended Space Elevator games (Monday Oct 22), the Univ. of Saskatchwan did a run with their green laser powered climber. An amazing YouTube video captured the run up the ribbon. http://www.youtube.com/watch?v=4cuLm1ripyU - Kurt updated to the Utah Astro current events entry for the Space Elevator Games _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Now THAT is a mount!
by Dale Hooper 29 Oct '07

29 Oct '07

http://www.astromart.com/classifieds/details.asp?classified_id=529001 Just plop your portable 24" RC on this baby and you are good to go! Clear skies, Dale.

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Where to get observing equipment?
by Michael Thelen 28 Oct '07

28 Oct '07

I've been using a pair of Wal-Mart binoculars for observing for a while now. They work okay, but they don't seem ideal for astronomical observation. Before I work my way up to a scope I think I'd like a better pair of binoculars and a tripod. Does anyone have any recommendations of where to get good equipment in the Salt Lake area? Thanks! -- Michael W Thelen Luck favors the prepared mind. -- Louis Pasteur

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Comet 17P - Best of the web image list on Utah Astro wiki
by Kurt Fisher 28 Oct '07

28 Oct '07

Links to the following hi-res "best of the web" images of Comet 17P have been collected on the Utah Astro wiki at - http://www.utahastronomy.com/Current_observing_events#From_the_web Anton Oct 10-27 (Russia). Best high-contrast detail image made using ISIS rgradient command Paolo R. Lazzarotti Oct 10-27 High-contrast coma Chris Petersen image time series Cloudbait Observatory, Colorado, with contour analysis of central coma "Tuggi" Univ. of Tuscon half meter scope image 10-273-day YouTube animation of coma growth "Tuggi" Univ. of Tuscon half meter scope image 10-26 "Tuggi" Univ. of Tuscon half meter scope image 10-25 Polarization Difference Image Richard Crisp 10-25 from the Web - William R. Mattil 10-25 Christian Buil spectrograph of 17P Oct 24 Xanadu amateur obs spectrograph _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Comet info pls?
by Kurt Fisher 28 Oct '07

28 Oct '07

Joe - P.S. - Kronk's Cometograpy website has a comprehensive review of the observing history on this comet going back to the 1800s. http://cometography.com/pcomets/017p.html Best wishes - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Comet 17P - Differential photometry experiment
by Kurt Fisher 28 Oct '07

28 Oct '07

Differential photometry - not color index corrected - was attempted as an experiment on Comet 17P on 2007-10-27 9:15 UTC. Using a wide-field camera consisting of a Meade DSI adapted to a fish-eye lens, a wide field (~14 deg) image of the region of Perseus around Comet 17P was taken. The image was dark flatted but not white flatted. Using lam Per as a reference star and AIP4WIN's single star photometry tool, a zero-point was adopted that yielded the Tycho V catalogue magnitude for lam Per. Using lam Per as the reference magnitude, differential photometry was tested on del Per and V 48 Per (MX Per). Estimated magnitudes were within the range of the small variation known for those stars. Differential photometery was then tried on Comet 17P resulting in an estimate of 2.59v+-2%. The comet is probably dimmer than this estimate as color index correction could not be included. There is no internet published color index for the comet. This experiment illustrates how wide-field digital SLRs might be used to prepare a time-series of differential photometry for Comet 17P. Comments and corrections to the above are welcomed and appreciated, as I am doing this as a hobbyist learning exercise. - Kurt Links - Image with data annotations http://gallery.utahastronomy.com/d/10501-2/20071027_17P_Photom.PNG (image with explanation) http://gallery.utahastronomy.com/v/kurt/solarsystem/Comet+17P+Holmes/200710… Photos about the adapted Meade DSI used to take the image http://gallery.utahastronomy.com/v/kurt/Meade+DSI+Studies/ResolutionTest/?g… _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Comet 17P - amateur spectrograph
by Kurt Fisher 28 Oct '07

28 Oct '07

Paul, FYI, this link is to Christian Buil's spectrograph of 17P. Buil arugably is the most skilled amateur doing spectroscopy today. http://astrosurf.com/buil/holmes/obs.htm - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Re: Comet info pls?
by Kurt Fisher 28 Oct '07

28 Oct '07

On 28 Oct 2007, at 14:46, Joe Bauman wrote: > What are the chances it will become a daytime object? And > will it show a tail one of these days? Thanks, Joe I don't know, but my best guess is (1) no it will definitely not be a daytime comet and (2) whether it shows a tail is uncertain and cannot be resolved with any certainty. The best stance is to enjoy its unique "head-on" view that we are now seeing that obscures most of its annular shape. See, e.g. in the Utah Astro wiki - http://www.utahastronomy.com/Current_observing_events#From_the_web - the following collected high contrast images that show detail in the diffuse coma - Anton Oct 10-27 (Russia). Best high-contrast detail image made using ISIS rgradient command Paolo R. Lazzarotti Oct 10-27 High-contrast coma Polarization Difference Image Richard Crisp 10-25 Concerning possible tail growth, this is not Comet McNaught seen earlier in the year. Comet McNaught had a highly ellipcital orbit that took the comet within the orbit of Mercury. From that position - the Sun really baked the comet and produced the huge 40 deg tail seen in the southern hemisphere. Comet 17P orbit - although inclined to the ecliptic - is almost entirely within the orbit of Mars and Jupiter - if viewed from the north ecliptic pole. That is why 17P's period is only 6.88 years. 17P is also on its outward bound leg - it passed perigee back in May. It should be getting dimmer - not have a huge outburst. In that Mars-Jupiter orbital bracket, Comet 17P is not going to be subjected to the types of intense solar radiation that creates the type of long-tail seen on Comet McNaught. Conversely, the diffuse coma of this comet is huge - now as big as the Sun. As one former astronomy college professor put it on a usenet group - "All that gas has to go somewhere." The key points about Comet 17P are its crazy unique characteristics. a) A small short period comet that should be dimming into astronomical obscurity suddenly blossoms into thermonuclear sphere (if it is a sphere) - for no apparent reason. Some speculative amateur-web suggestions are i) an impact with another comet or asteriod or ii) it is breaking up from the gravitational influence of Jupiter. b) Looking at its rate of expansion - the speed of the expanding wave front on this comet has been estimated (by an amateur) at 1,500 km/ per hour. c) It is presenting a unique "head-on" apparent view towards Earth. Most comets are seen from the side. Comet 17P has been a nice suprise warm-up for Comet Tuttle's scheduled return beginning around Christmas. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Re: [Utah-astronomy] Comet 17P - Corrected size estimate
by Kurt Fisher 28 Oct '07

28 Oct '07

In a Cloudy Night's forum, someone pointed out that you can use the Google search box's built-in calculator to find the physical size of Comet 17P. In general - sin ( radians (your_arcmins arcmins) ) * 1.62900 [a.u.] * 149 597 871 = physical size 17P Get the current day's distance to Comet 17P from the NASA-JPL Near Earth Object orbit simulator - http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=17P&orb=1 An example of a string that is formated for use in the Google search box is: sin(radians * (10 arcminutes)) * 1.62900 * 149 597 871 which yields = 708 878.821 kilometers According to Allen's Astrophysical Quantities, typical comet coma physical diameters are 10,000 to 100,000 km. - Kurt Updated to Utah astro wiki current events _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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