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

Re: [Utah-astronomy] DesctructiveGear.com
by Wayne Sumner 17 Jun '08

17 Jun '08

I just picked up the laser from Seth about an hour ago. Night cannot come soon enough for me tonight! Wayne A. Sumner Math/Physics/Astronomy/Engineering Boy's Tennis Coach Northridge High School Davis School District (801) 402-8610 >>> "Chuck Hards" <chuck.hards(a)gmail.com> 06/16/08 8:41 AM >>> I had the laser out again last night. I am just amazed at the beam visibility. The fat, bright gibbous moon was no competition for the beam at all. Wayne, you're in for a treat! _______________________________________________ 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://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com

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Suggestion for a future monthly meetingpresentation
by Canopus56 17 Jun '08

17 Jun '08

Patrick wrote, > Possibly. Most of what I do centers on Newton's Laws and > "Fun with liquid nitrogen" so I'm not sure what other > fun things might be available. Patrick, The following may be of interest from the UCLA Physics Department Demonstration Manual helpful: H Spectrum projection (simple large 2ft diffraction grating behind arc tubes) http://www.physics.ucla.edu/demoweb/demomanual/astronomy/light_spectra_atom… Projection of Spectra (complicated setup) http://www.physics.ucla.edu/demoweb/demomanual/optics/spectra/projected_mer… Sodium Absorption http://www.physics.ucla.edu/demoweb/demomanual/astronomy/light_spectra_atom… UCLA Physics Demo Manual, generally http://www.physics.ucla.edu/demoweb/demomanual/index.html Maybe if you could fit in this demo. -:) http://www.physics.ucla.edu/demoweb/demomanual/unusual/large_arc.html - Kurt

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Thursday night launch
by Patrick Wiggins 17 Jun '08

17 Jun '08

OSTM/Jason-2 ( http://topex-www.jpl.nasa.gov/mission/ostm.html ) is set to be launched from VAFB in S. California Thursday night between 2346 and 2355 MDT. Past launches from there have been visible from here in Northern Utah (I saw one from the Midvale Harmons) so I'm guessing it's possible this one could be visible too. patrick

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Smoke from CA wildfires
by Canopus56 17 Jun '08

17 Jun '08

Erik wrote in another thread: > And Speaking of fires bad news is that smoke is building > in atmosphere from So Cal Fires. Another smokey summer? WRT the current haze, that smoke plume coming off those northern California wildfires and feeding into the jet stream looks bad. Go south, young man! http://www.firedetect.noaa.gov/viewer.htm - Kurt

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Re: [Utah-astronomy] Ealing targeting errors - an overview
by Canopus56 17 Jun '08

17 Jun '08

Chuck wrote: > I've avoided the Ealing mostly because > of it's idiosyncrasies; you've found the way to tame it. Reminds me of Bessel's "twice built telescope" maxim. Between the problems in my 10" GEM and the Ealing, seems to be that I have been karmically channeling Bessel over the last year. >From Karl Giberson's review of Hirschfield's _Parallax_: "Bessel's observational prowess, which had a strong theoretical dimension, was legendary. He developed the concept of the "twice-built telescope." Bessel knew that any telescope, . . ., had flaws that would interfere with the kind of precision measurements . . . . So he figured out a way to build a 'mental' model of the telescope that would expose its various idiosyncrasies. Knowledge of the mental model allowed the user to make allowances for the limitations of the telescope." http://www.metanexus.net/magazine/ArticleDetail/tabid/68/id/5292/Default.as… - Kurt

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Re: [Utah-astronomy] The Lagoon?
by Canopus56 17 Jun '08

17 Jun '08

Joe, Nice round stars. My guess is that you in the center of the Lagoon open cluster. It is the bright open cluster of stars emerging from the nebula that is seen in Don's image. http://gallery.utahastronomy.com/main.php?g2_itemId=11551 The Lagoon open cluser is more enhanced in the following APOD. http://antwrp.gsfc.nasa.gov/apod/ap960127.html The center of the cluster is at about J180501.8-242029. - Kurt

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Re: [Utah-astronomy] DesctructiveGear.com
by Wayne Sumner 17 Jun '08

17 Jun '08

WOW! Antaries was a half degree from the moon last night and the 75 watt laser pointer I picked up from Seth Jarvis yesterday was wonderfully bright pointing at it, even from 50 feet away. Thanks, Seth. Wayne A. Sumner Math/Physics/Astronomy/Engineering Boy's Tennis Coach Northridge High School Davis School District (801) 402-8610 >>> "Chuck Hards" <chuck.hards(a)gmail.com> 06/16/08 9:12 PM >>> I've noticed the reddened sunsets and murky afternoons. I think you may be right, Erik. If the laser ignited my dry grass mulch, only my tomatoes would be lost. My wife would be very upset, but Smokey the bear probably wouldn't care. I think astronomers are probably more fire-safe than most campers, for the simple reason that they eschew the otherwise ubiquitous campfire. On Mon, Jun 16, 2008 at 7:56 PM, <erikhansen(a)thebluezone.net> wrote: > >Another smokey summer? > > I was going to discourage someone from trying it, but your own backyard is > acceptable. Would not make for good headline. _______________________________________________ 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://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com

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Re: [Utah-astronomy] Ealing targeting errors - an overview
by Canopus56 17 Jun '08

17 Jun '08

Chuck, Thanks for your kind words. As to a somekind of replacement with a slo-mo control for the "U" bar that holds on the Mak, weight would be problem for Bruce. I notice in "Jim's Album" in the gallery, this item, titled "Chuck Hard's weightless mount" - http://gallery.utahastronomy.com/main.php?g2_itemId=5478 - Kurt

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Suggestion for a future monthly meeting presentation
by Canopus56 17 Jun '08

17 Jun '08

I have been getting started in the spectroscopy over the last month, but do not have some of the same basic science education as other club members. It would be helpful for me to see a demonstration of the spectral emissions on a student spectrometer. Patrick, I understand that you are part-time employed as a demonstrator at the U and believe that you may have access to the necessary gear - the student spectrometer, reference gas tubes for H,He,Fe and Na, and a high voltage power supply. I am available to work out the details of connecting a Meade DSI-C or webcam to the student spectrometer for projection and viewing on the lecture hall screen. Regards - Kurt

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Ealing targeting errors - an overview
by Canopus56 16 Jun '08

16 Jun '08

These notes summarize my walk through the Ealing over the last month in an attempt to overcome my problems targeting faint fuzzies with that scope. I hope these notes are of use to other Ealing operators. I'll end by making some upgrade recommendations to the SLAS membership and Board intended to make the Ealing easier to target. Difficulty in targeting the Ealing is caused by 1) its inherent small eyepiece TFOVs caused by its long focal length and 2) targeting inaccuracies in the mechanics of the scope. Under standing the sources of Ealing targeting errors allows the operator to compensate and get on target faster. The main sources of targeting errors on the Ealing are: 1) Focuser tube flop. The focuser tube is alway loose in the aged rake and pinion focuser. Compensate for this by retargeting all the finders on a bright star after each meridian flop and realigning the Skywizard. Yes, that's after every meridian flop or slew in declination over 30 degrees. 2) An inherent 0.3 deg RA error in the Skywizard. This is probably a misadjusted encoder. Compensate for this using the Mak 1 deg finder. Undertstand that after a slew from a bright alignment star, the faint fuzzy will inherently not be at the center of the Mak eyepiece TFOV. It will alway be off to one side. 3) Drive motor calibration. The Astrophysics Model 8002 drive controller is usually not calibrated. If you are using the Skywizard to locate objects, about 1 ep TFOV of drift will accumulate in the Skywizard every half hour. Properly calibrate the drive controller on each use to reduce this error. (The calibration setting may change, if you are observing at 60 degrees at opposed to 80 degrees in alt.) 4) Mak targeting index error Because the Mak finder is difficult to align centered on a target, centering the target in the Mak does not center it in the small TFOV of an Ealing eyepiece. Compensate for this error by using the double search and observing flip-mirror eyepiece setup described in prior posts. The Mak 1 deg TFOV will get you near the target, the 52mm search ep acts as a bridge between the Mak 1 deg and the small 20 arcminute TFOV of an Ealing observing ep. The Mak targeting error also can be compensated for partially by using the index error wheel described in prior posts. 5) Double search and observing flip-mirror setups - targeting error. Because flip-mirrors are never exactly 45 degrees when "flipped", they introduce another targeting error. For a small TFOV ep on the Ealing, the targeting error can be enough to hover the object outside the ep field-of-view. Compensate for this error by using the index error wheel described in prior posts or in combination with a reticule ep. (Reticule eps have an miniscule TFOV on the Ealing (less than 7 arcminutes) and are must useful for centering binaries on a camera chip.) About $1,000 to $1,500 in mechanical upgrades to the Ealing can make the scope smartly target faint fuzzies during star parties and make the Ealing an enjoyable experience for club users. The upgrades would also make the Ealing a good learning and teaching platform for astrophotography. First, the old rack and pinon focuser could be replaced with a modern high-end Crayford focuser. If possible, I'd suggest stacking two low profile Moonlight focusers so there are 8 points of support contact bewteen the Crayford rollers and the focuser tube. The low profile focusers will not reduce the available back focus. Second, the Mak finder could be mounted on a slow motion control alt-az head. An Astronomics head is featured on page 36 of July's ST. The Vixen Porta alt-az head might be another option. The Astronomics head could be sawn off, using only part of the support arm, and only the slow motion control head bolted to the Ealing frame. If the Astronomics head is too heavy, I assume there are options other than the existing rigid "U" bar. Third, if SLAS still has the ancient Ealing autoguider floating around, and it still works, it could be moved back to the control room. An offer could be made to Chuck to sell SLAS his contorller. My apologies for the number of posts that I have made about the Ealing over the last month and in particular over the last few days. I hope the info is of use and has not been nuisance listserv posting. Regards - Kurt

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