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

How to make mosaic - Utah astro wiki update
by Kurt Fisher 26 Nov '07

26 Nov '07

Added some misc urls to articles and software on making mosaics to the Utah Astro wiki. http://www.utahastronomy.com/Observing_resources#How_to_make_mosaics - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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New Occult version 4.0 software available (issued 11-2007)
by Kurt Fisher 26 Nov '07

26 Nov '07

http://www.utahastronomy.com/Current_observing_events#Occult4 David Herald. 11/2007. Occult version 4. http://www.lunar-occultations.com/iota/occult4.htm This is the IOTA's recommended software for predicting lunar occultations and grazes. An extremely cool piece of software. For Windows XP and Vista users, requires pre-installation of Microsoft .NET framework 2.0 or higher and Microsoft Visual J# runtime package discussed at the Occult4 website above. Most Windows XP machines and Vista machines have Microsoft .NET 2.0 or higher installed. You will only need to install the Visual J# runtime package for installing Occult4. This software is used to predict lunar grazes and or lunar occultations of double stars between 1" and 0.1" in separation. Such stars cannot be separated visually and usually are not spectroscopic binaries. The newest version of Occult has many new features that integrate it with Google Earth and Google Sky. On my Windows XP install, the Google Earth options did not activate within Occult4. To repeat. This is one cool piece of software. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Re: [Utah-astronomy] Quick pic - 360 deg lunar halo - 11-22-2007
by Kurt Fisher 23 Nov '07

23 Nov '07

This lunar halo measured against an outstretched hand at about 20 degs in diameter. It may have been a halo of an unusual radius type - a Van Buijsen 8.3 deg radius halo. Halo's normally form at 22 or 46 degrees. Rare angle halos can form where the light traverses a hexgonal ice crystal that is capped on the ends with pyramid shapes. See Lynch and Livington, Color and Light in Nature (2d 2001) at p. 170. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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0=South 180=North
by Patrick Wiggins 23 Nov '07

23 Nov '07

While plotting Comet 8P/Tuttle this morning I came across an oddity (at least it was odd to me) at the Minor Planet Center. Since it involves finding Comet Tuttle I thought it might be helpful to post about it here. After plotting the comet on my computer's virtual sky I went to the Minor Planet & Comet Ephemeris Service ( http://cfa-www.harvard.edu/ iau/MPEph/MPEph.html ) and downloaded the position of the comet as seen from my location for the next few hours. While the altitude of the comet in my Mac matched with what MPC reported, the azimuth was off by 180 degrees. Where the Mac said the comet is due north, MPC reported the comet's azimuth as 179. To me that meant due south. I posted a question about this on the Minor Planet list and heard from several people that MPC follows an old convention which has 0 being south and 180 being north. So if you plan on using MPC to find Tuttle (or any other object for that matter) keep the 180°-out-of-phase thing in mind. patrick

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Quick pic - 360 deg lunar halo - 11-22-2007
by Kurt Fisher 22 Nov '07

22 Nov '07

Happy T-day to all. Kurt http://gallery.utahastronomy.com/v/kurt/atomsphere/20071122_lunarHalo3.jpg.… _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Rob's Holmes pix
by Patrick Wiggins 21 Nov '07

21 Nov '07

I don't think Rob has mentioned it but he's got a couple of nice shots of the comet on his gallery page. http://gallery.utahastronomy.com/v/rob/?g2_page=4 patrick

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Re: [Utah-astronomy] Re: Lunar occultation of Pleaides obs op 11-24 beg 4:40am
by Kurt Fisher 21 Nov '07

21 Nov '07

Patrick wrote: > Last night's SLAS speaker came to advanced training > after the meeting and a few of us spoke with him > about trying to arrange to get 2 widely separated > (ie. Hawaii and Utah) scopes to take pictures > of the Moon at the same time during a Pleiades > occultation and later viewing the pictures using > stereo viewers to see the 3D effect. Yes. Pete Lawrence did a couple of those back in 2003 and 2004 that I did some follow-along working computations on, e.g. - determining the parallax from the subsurface baseline between two widely separated cities. They're fun. http://www.digitalsky.org.uk/LPDP/LPDP-Update2004.html This looks like good chance to due another one - while also taking some pretty pics. > Actually, the bright limb of the Moon covering a > star or (or planet or minor planet) is still called > an occultation. But they can also be hard to see > especially with fainter stars. Thanks, Patrick. The context of the post and the utah asto wiki entry was detecting the 0.1" split between 16 Tau's components using a light curve derived from video of the occultation. My understanding from the ITOLA handbook is that unless the occulting limb is dark, there is not enough contrast to pull out any meaningful curve. Since you are experienced in these observations, is that correct? - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Re: [Utah-astronomy] Lunar occultation of Pleaides obs op 11-24 beg 4:40am
by Kurt Fisher 21 Nov '07

21 Nov '07

Looks like this was bad call on my part. To observe lunar occultations, it appears that there needs to be a dark limb on the side of the occulted star. The 11/24 occultation of the Pleaides will occur on the night of the full Moon - hence no dark limb. It should still make for a good asthetic picture opportunity. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Re: [Utah-astronomy] Observation report about Comet 17/P Holmes
by Kurt Fisher 20 Nov '07

20 Nov '07

Here's a quick pic I took on the night of 11-19 at 2am with a telephoto lens. Nothing to write-home about compared to the same pic on today's spaceweather.com. http://gallery.utahastronomy.com/v/kurt/solarsystem/Comet+17P+Holmes/039.PN… 17P dimmed rapidly between 11-16 and 11-19 (~ 1 mags) and was further washed out by a 1st quarter Moon. It was no longer visible with the naked eye and is best seen when on the zenith after the Moon set. Here, the comet is at approx. alt 75 degs and visually showed less detail then when on the zenith. But on the zenith with a small refractor, it was still a heart stopper partially covering Mirfak. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Comet 8P Tuttle - Prior reports or photos
by Kurt Fisher 19 Nov '07

19 Nov '07

>From Kronk's 8P webpage, I understand that this 13.6 year period comet was not visible to most amateurs in 1994, but that it may have been better seen in 1981? and early 1967. In preparation of next month's passage, do any of you greybreads out there have any notes or photos to post on how it looked in the earlier passages? - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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