January 2009 - Utah-Astronomy - mailman.xmission.com

Re: [Utah-astronomy] Predicting the brightness of a satellite at distance x, how to
by Canopus56 18 Jan '09

18 Jan '09

I made a simple magnitude model of the LCROSS-EDUC brightness at various observer-booster distances out to 400,000 km. The results of the model are shown graphically in two figures: Magnitude by distance http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090118Ce… y axis = Centaur estimated apparent magnitude; x axis = observer satellite distance km Minimum aperture by distance http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090118Ce… y axis = minimum aperture inches; x axis = observer satellite distance km The simple model has based on two Centaur booster records in the CalSky and Heaven's Above satellite databases that describe the apparent magnitude at perigee (100% illumination) and at a standard distance of 1000km (50% illumination): Object USSPACE-CMD Id Int’l ID MStar 3 Cent Rocket 25725 1999-023B USA 136 Cent Rocket 25035 1997-068B The MStar 3 Cent Rocket is a currently observable satellite. Heaven's Above has more that 150 observations for this object, the last being on 17 Jan. 2009. The simple magnitude model is based on differential magnitudes and a simple telescopic limiting magnitude equation: m2 - m1 = 5 * log10(d2/d1) Distance modulus formula m2 = 5 * log10(d2/d1) + m1 Distance modulus formula solved for m2 m2=1.8 + 5*log10(D_mm) where m2 is Telescopic Limiting Magnitude. Steavenson-Sigdwick simple telescopic limiting magnitude (TLM) D_mm = 10^(m2-1.8)/5) where m2 is Telescopic Limiting Magnitude. Steavenson-Sigdwick TLM solved for minimum aperture to observe a magnitude. A spreadsheet of supporting computations can be found at: http://members.csolutions.net/fisherka/astronote/observed/LCROSS/20090118EU… Comments and criticisms of the above are welcomed and appreciated. I am looking for confirmation by more experienced observers that the approach is sound and that there are no basic thinking errors in it. Thanks, Kurt

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Space junk flyby
by Jim Gibson 18 Jan '09

18 Jan '09

Hi Patrick, I was just reading the mail on MPML ({MPML} 9B82224 = unusual object) about the possible space junk coming our way. After your last success you may be following this one too; may be too far away though. I am just curious. What can I do with the data such as the astrometry or the ephemeredes data? Can I use it in my planetarium software? I don't have a tracking mount. I am not sure what it is telling me. Yeah, I recognize the RA and Dec but I am not sure what the delta, r and some of those other things are for. Is there a program a person can down load to compute the trajectory or orbit of stuff like this? Just curious. Don’t want to miss out on something because I am too dumb to use the data. http://www.projectpluto.com/mpec.htm#elements Thanks Jim Gibson

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New Hydrogen Alpha Image
by Tyler Allred 16 Jan '09

16 Jan '09

Hello all. I got some imaging time last night and decided to take some Ha data of IC443, a supernova remnant in Gemini. I really like this object, which is also known as the jellyfish nebula. The link below will get you to the "Latest Images" section of my website. http://71.18.228.62/gpage8.html Be sure to click on the images a few times to get to the full versions (if you want to see them). Image details are on the website. Thanks for looking. Tyler _____________________________________________

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Predicting the brightness of a satellite at distance x, how to
by Canopus56 16 Jan '09

16 Jan '09

I would like to make a rough mathematical estimate of the magnitude of a Centaur booster at various distances between 500 and 400,000 kilometers. The object is 12 meters long by 2.5 meters in diameter. The albedo is not known. A best guesstimate of the albedo will have to make? Can anyone provide a formula or reading references? Thanks, Kurt P.S. - I have already collected empirical examples of detections at various distances.

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Personal space shuttle test at Bonneville Salt Flats
by Canopus56 16 Jan '09

16 Jan '09

This is a link to a video story about a private aerospace engineer who is building his own suborbital space shuttle named "Hermes". http://cosmos.bcst.yahoo.com/up/player/popup/?rn=4226712&cl=11527165&src=ne… The story ends stating that the builder intends to bring the shuttle to the Salt Flats in a few months for testing. - Kurt

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Fw: Celestial Navigation offering
by Richard Tenney 16 Jan '09

16 Jan '09

--- On Fri, 1/16/09, Todd & Louise Frye <nowbringmethathorizon(a)sisna.com> wrote: > From: Todd & Louise Frye <nowbringmethathorizon(a)sisna.com> > Subject: Celestial Navigation offering > To: retenney(a)yahoo.com > Date: Friday, January 16, 2009, 9:40 AM > Greetings, > > I operate a sailing school on Utah Lake and during the > winter months, offer > related educational classes. New for 2009, we will be > offering Celestial > Navigation I & II. Our instructor is a retired math and > physics instructor > who has sailed the Atlantic, Pacific, Mediterranean and > Caribbean using > sextant only navigation. Would it be possible to announce > these classes > (beginning in March) to your astronomical society? Would > you like to be > included on our "links" page? > > http://www.nowbringmethathorizon.com/ > > Thank you for your considerations, > > Todd Frye > Director > Bonneville School > of Sailing and Seamanship > 801-404-0098

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Re: [Utah-astronomy] Another movie from P Wiggins StarDust Bus flyby
by Canopus56 15 Jan '09

15 Jan '09

> I could burn them onto a CD and get it to > you at Tuesday's meeting if you like. Yes, that's fine. I mispoke. One can only do differential, not absolute, photometry with the images. But that's close enough. - Kurt

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Re: [Utah-astronomy] Another movie from P Wiggins StarDust Bus flyby
by Canopus56 15 Jan '09

15 Jan '09

Kudoos again, Patrick. Thanks for the extra-credit. If you ever get a set of flatted FITs files together, let me know and I'll run them through MPO Canopus or AIP4WIN to get the differential and absoute photometry and astrometric data. - Kurt

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Re: [Utah-astronomy] Another movie from P Wiggins StarDust Bus flyby
by Canopus56 15 Jan '09

15 Jan '09

> You were thinking about a star field with a trail of dots right? That's right Howard. Patrick said he is doing dark and white flats. That also may help by subtracting out some of the noise. - Kurt Patrick wrote: > BTW, I heard from NASA this evening that the movie Kurt put together > may go on their website tomorrow. Congrats. You're too modest. You mean the images that you took will be on the NASA website in the form of a movie. -;) - Kurt

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Re: [Utah-astronomy] Another movie from P Wiggins StarDust Bus flyby
by Canopus56 15 Jan '09

15 Jan '09

Impressive imaging capture. "The overall length of the main bus is 1.7 meters, about the size of an average office desk." You imaged at 5UT at 35,000km. http://stardustnext.jpl.nasa.gov/mission/spacecraft_details.html Think I'll draw my blinds a little closer at night. -:) Kurt P.S. Does anyone have multi-image merge in their image processing software? I'd like to make a combination of the images showing the track. API4WIN has image merge (aA+bB+c) for two images but no way to automatically sequentially merge across 37 images. Simply summing the images does not quite cut it. The spacecraft becomes too faint as the background noise is summed. - K

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