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

Photogenic Sunspot Active Region 953
by Kurt Fisher 28 Apr '07

28 Apr '07

Our usually quiet Sun has a new large sunspot worth checking out. See http://spaceweather.com/ for details. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

1 0

Gassendi and Rima Hippalus at Harmon urban stary party
by Kurt Fisher 28 Apr '07

28 Apr '07

Dan [Turner] [offline and in Utah Astro], Thanks for letting me use your 16" DOB at last night's urban star party. Most of the interesting features on the Moon are organized around impact basins. http://members.csolutions.net/fisherka/astronote/Structure/moongeo/MoonGeol… Once you understand the relationship between the basins and strucutral features, finding feature feature types is straight-forward. http://members.csolutions.net/fisherka/astronote/Structure/moongeo/MoonGeol… For example, we were looking at Gassendi last night, a floor-fractured crater on the edge of Mare Humorum that, like many floor fractured craters are tilted towards the center of the mare. We also looked at Rima Hippalus, a series of parallel fractures tangent to the east side of Humorum that related to the basin's formation. Gassendi http://www.lpod.org/archive/archive/2004/01/LPOD-2004-01-15.htm Rima Hippalus http://www.lpod.org/?m=20060421 - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

1 0

Observing notes - Ealing 4-26-2007 Lunar visual
by Kurt Fisher 28 Apr '07

28 Apr '07

Don Colton wrote, > I question whether you will get diffraction effects based on > aperture on the moon at 560X with the Ealing. . . . . > You may, also, be getting deterioration of the image due to > the quality of the eyepiece. I have found some eyepieces > perform very poorly at high power. Good point. I do have low-end eyepieces and did not try my one 20mm Nagler. The specific lunar test for diffraction deterioration that I use are fine rilles - like Rima Gay-Lussac (Rukl 31) mentioned in the prior post. At lower magnification, the rille was crisp. At extreme power, parts of the rille visible at lower power, appeared broken and merged with the surrounding terrain. This visual effect held even during periods of calm - thus ruling out atmospheric turbulence as a cause. My understanding is that this is an effect of the diffraction waves overlapping each other at extreme mag. But the low-end eyepiece probably is the right cause. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

4 5

Observing notes - Ealing 4-26-2007 Lunar visual
by Kurt Fisher 27 Apr '07

27 Apr '07

Observing notes - Ealing 4-26-2007 Lunar visual 9:30pm - 12:30am 4/26-4/27. Temp. 48 deg. Sky brightness 16.5B (v2.7). Moon az 183, alt 58. Terminator approx. W 28 deg. Lunar age 9.6 days. Seeing: 4/5 poor. Wind at 9pm 5mph dropping to zero after 11pm. Basic night of lunar visual observing with objective of testing lenses and maximum useable magnification against lunar targets. With the Ealing's 5080mm focal length, a 9mm lens yielded about 560 power, a TFOV of about 330 arcsecs, and an linear lunar FOV of about 650 kilometers. At 560x, diffraction limited effects began. This was consistent with a magnification per inch of aperture of 35.8 - a power useful for resolving specific lunar and planetary detail. A 6mm lens at 840x was also tried. The image was useable for investigating small details but showed severe diffraction limited effects. At 53.8 mags per inch, this is a power appropriate for double star work. I began the evening at C. Copernicus. The terminator was to the west, crossing to the west of C. Lansberg and C. Hortensius. Rukl Charts 31 and 32. This put Copernicus in low angle illumination of about 8 degrees. At 158x, the Copernicus region and the surrounding dark pyroclastic deposits of west and central Sinus Aestuum and Rime Bode had good contrast. http://members.csolutions.net/fisherka/astronote/plan/dhccat/DarkHaloCrater… At 560x, the dark halo crater Copernicus H (Rukl 31) could be distinguished as a DHC. Although seeing was poor, paradoxically, difficult lunar object Rima Gay-Lussac was visible with good detail to the north of Copernicus. (Rukl 31). My principal interest in this region was to watch sunrise over the eastern end of the Hortensius dome field. (See Rukl 31) LPOD 3-26-2004 - view of the Hortensius dome field http://www.lpod.org/archive/archive/2004/03/LPOD-2004-03-26.htm The classic domes north of Hortensius - Hortensius 2, 3, 4, 5 6 and 8 shown in the 3-2-2004 LPOD were viewed for about an hour coming out of the lunar terminator at illumination angles of 0 to 2 degrees. After a brief trip north to view a low-angle 50-kilometer shadow cast off of Promontorium Laplace on the east end of Sinus Iridum (Rukl 10), I then wandered south past Copernicus and prominent crater Bulliadus (Rukl 53). Lunar dome pi Kies was especially well lit, showing a good illumination gradient on both the sunward and terminator sides. (Rukl 53). LPOD 3/23/2007 - C. Kies and dome pi Kies. http://www.lpod.org/?m=20070323 Kies is about 100 kilometers north of one of the longest rille on the Moon - Rima Hesiodus. In low angle light at 560x, I was able to trace Rima Hesiodus from its eastern beginning in the wall of C. Hesiodus (Rukl 54) for about 250 kilometers before it disappeared into the terminator north of C. Capuanus. (Rukl 63). LPOD 2/20/2005 - R. Hesiodus http://www.lpod.org/archive/LPOD-2005-02-20.htm Note how the rille fractures a mountain range - Rupes Mercator - (Rukl 53) in the process. The east graben of fractured-floor C. Pitatus (Rukl 54) under low-illumination showed a distinct tilt relative to the other subsections of the crater floor. LPOD 3-13-2007 - Pitatus and R. Hesiodus http://www.lpod.org/?m=20070313 The lunar part of the evening ended with a dramatic sunrise over C. Capuanus that took up a good 15 minutes of viewing. A peak on the east wall of Capuanus cast a sharp triangular shadow across the crater floor, ending in a point on the west wall of the crater. LPOD 2/11/2005 - Capuanus http://www.lpod.org/archive/LPOD-2005-02-11.htm After a snack and some coffee, it was time to switch to a quick colorful double star before closing the Ealing roof cover for the night. Belmont Society recommended bright colorful double eps Boo has a 3 arc separation with a white-yellow primary and a dimmer topaz secondary. The 6mm lens at 860x nicely split this colorful double, but the size of the seeing disk of the primary put atmospheric turbulence at about 2 arcsec. eps Boo is ST513 in the Ealing Skywizard DSC - useful info for the next couple of Moon washed-out sky. Clear skies - Kurt P.S. An owl and several bats were heard throughout the night. The dog at the house to the northwest incessantly barked from 9:30pm to 1am - similar to its behavior in past years. That dog really has the potential to create some conflict between the home's owner and the observatory. _______________________________________________ Sent via CSolutions - http://www.csolutions.net

3 2

Re: Utah-astronomy] Observing notes - Ealing 4-26-2007 Lunar visual
by Kurt Fisher 27 Apr '07

27 Apr '07

To correct: >At 158x, the Copernicus region and the surrounding dark pyroclastic deposits of west and central Sinus Aestuum and Rime Bode had good contrast. >http://members.csolutions.net/fisherka/astronote/plan/dhccat/DarkHaloCrater… >At 560x, the dark halo crater Copernicus H (Rukl 31) could be distinguished as a DHC. Although seeing was poor, paradoxically, difficult lunar object Rima Gay-Lussac was visible with good detail to the north of Copernicus. (Rukl 31). Should have read: At 158x, the Copernicus region and the surrounding dark pyroclastic deposits of west and central Sinus Aestuum and Rime Bode had good contrast. http://members.csolutions.net/fisherka/astronote/plan/dhccat/DarkHaloCrater… At 560x, the dark halo crater Copernicus H (Rukl 31) could be distinguished as a DHC. Although seeing was poor, paradoxically, difficult lunar object Rima Gay-Lussac was visible with good detail to the north of Copernicus. (Rukl 31). http://members.csolutions.net/fisherka/astronote/plan/dhccat/DarkHaloCrater… - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

1 0

ISS tonight (Wednesday)
by Patrick Wiggins 26 Apr '07

26 Apr '07

Nice ISS pass tonight (Wednesday) for northern Utah. 21:15 Appears in NW 21:19 Transits high in SW 21:21 Disappears in SE pw

3 3

Re: [Utah-astronomy] Seeing monitor on South U Physics Bldg
by Kurt Fisher 25 Apr '07

25 Apr '07

Chuck said, > Do you think that the U data set could be useful > for a broad characterization of the valley-at-large? No, especially since to point it at Polaris, the box is sighted over the south end of Black Mtn. But again, some data is better than no data at all. -:) > How much are those monitors? One at SPOC might provide interesting data. The list price was around $2500. My guess is that club members are satisfied with eye-balling seeing and their experience. Borrowing or renting it from the U or asking that they undertake a "special ancillary study" at SPOC once they are done at Boulder Mtn. would be another idea. A potential problem mounting a seeing box at SPOC is security. The Physics Building is a secure facility. An exterior box at SPOC would be at higher risk for theft. If such an idea were to be pursued, another lower cost idea might be to have a post mounted objective that projects into the control room, or a viewport coming out of the side of the control room. That would keep the camera securely inside the building. A donated pc and a cheap camera could function as a recorder. Such a set up would also be useful for site ZLM characterization and light pollution documentation, if the objective can be rotated straight-up or a flip-mirror used for zenith or polar orientation. Another useful seeing test that you can do to support your astrophotography are seeing estimates by length of exposure. Basically, you take a series of photos of a bright star for 10, 15, 30, 60, 90 and 120 secs and then measure the FWHM of the star. That gives you an idea of how much distortion you get at a site for a given exposure length. Haven't done one myself, but here's a pro article that illustrates it: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1989PASP..101..436R - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

1 0

Subject: Re: [Utah-astronomy] Seeing monitor on South U Physics Bldg
by Kurt Fisher 25 Apr '07

25 Apr '07

Rich wrote, > Is the data from the SBig device different from that being > reported by the Clear Sky Clock? Yes, it is different in quality from the Clear Sky Clock. The Clear Sky Clock is based on a mathmetical model on the macro (+300 miles) and meso scale (10-300 miles) and has no "time memory". A micro site seeing study is on a micro scale (<10 miles) and gives continuous readings that identify probable hours during the night of excellent seeing. The Clear Sky Clock seeing index is a further abstracted index of a northern hemisphere seeing model maintained by the Canadian Meterological Service. The Clear Sky Index is a number 1 to 5 ranging from good to bad. The CMS model is based on satellite photographs. http://www.weatheroffice.gc.ca/astro/seeing_e.html The CMS model operates on the macro (+300 miles) and meso scale (10-300 miles). As the Clear Sky Clock website says of their index: "It's an experimental forecast." The type of data you get from continuous seeing monitoring is on the micro-scale - less than 10 miles. Characterizing the seeing at a particular site using continuous monitoring produces an average hourly turbulence measurement in terms of arcsecs. The SBIG website has a sample graph. Typically, we use 1 arcsec as a nominal aveage turbulence and as a seeing limit. So, once your scope has a resolution performance below 1 arcsec (e.g. about 10 inches of ap and above), telescope's resolution performance does not get used (absent adaptive optics that professionals use or by lucky imaging). 10 to 16 inch DOBs have a better resolution than this average - they will resolve down to 0.5 or 0.6 arcsecs. Contrast that value with the best sites in the world - like Mauna Kea - that has an average 0.5-0.6 arcsec seeing. While 1 arcsec of turbulence is the usual average value for "average" or "good" seeing, there are times of calm where turbulence can fall lower. A seeing monitoring study helps characterize those hours of the night when, at a particular site, those times of atmospheric calm below the 1 arcsec limit are most probable. Intuitively, you SPOC old-timers know when those times are (the early morning hours) based on years of observing experience at SPOC and other favored sites. The seeing monitor just puts an objective number to what you already know in your gut. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

1 0

Seeing monitor on South U Physics Bldg
by Kurt Fisher 25 Apr '07

25 Apr '07

A short correction to my post on Astronomy Day - I incorrectly had the impression that the atmospheric turbulence measuring box on the top of the University of Utah South Physics building was something that the Physics Department cobbled together. In surfing the web, it turns out that the box is an off the shelf commercial product made by SBIG - an SBIG seeing monitor: http://www.sbig.com/products/seeingmonitor.htm The seeing monitor houses an SBIG ST-402ME camera in a weatherproof box. To my knowlege, there is no formal characterization of the seeing over Salt Lake City. Might be a thought to ask the U Physics Department for a data file when they are done testing the box and before they move the seeing monitor to the field in central Utah. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

3 2

Re: [Utah-astronomy] Discovery of Earthlike Extrasolar Planet
by Joe Bauman 25 Apr '07

25 Apr '07

Answer: I have no say over where any story runs or how big they run a national article. I'm just a humble reporter. Thanks, Joe >Today, the Salt Lake Tribune had a front page story on the discovery >of an extrasolar planet having possible Earthlike temperature >conditions. It is probably a rocky planet, considering its distance >from its sun, and its mass. The mass is also possible to sustain >life, though the gravity would be stronger than that of Earth. They >don't know yet, if the planet has water. I don't know if they have >any information about the atmosphere of the planet. Probably not. >The Deseret Morning News had a similar article on the back of >today's A Section. I wondering why Joe Bauman didn't put in a front >page article on this, in the Deseret Morning News? > > Sincerely, > > > J. David Baxter >_______________________________________________ >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

2 1