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

Re: [Utah-astronomy] -8 is bright!
by Kurt Fisher 25 Jun '07

25 Jun '07

Wayne asked: > <snip all> If you do not have a planisphere available, Wayne, you can also use the online planetarium program to prepare a chart at sunset. http://www.fourmilab.ch/cgi-bin/Yoursky Set a horizon view for Salt Lake City at 2007-06-26 2:45:00 Universal Time. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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RE: [Utah-astronomy] -8 is bright!
by Kurt Fisher 25 Jun '07

25 Jun '07

Wayne asked: > I have observed, with my aging eyes and an old protractor, > that the apparent difference in the position of the sun, > at sunrise or sunset, on June 21st is approximately > 65 degrees north of its position, at sunrise or sunset, > on Dec 21st. . . . I expected the distance to be 47 > degrees. (Twice the angle of the earth's tilt.) Why > wasn't it 47 degrees? A hand-held plainisphere set to the time of sunset will help in visualizing path of the ecliptic and celestial equator discussed below. A small plainisphere can be bought at Clarke Planetarium for about $10. At the equinoxes, e.q. last March 21, the altitude of the Sun is equal to 90 degrees minus the latitude of Salt Lake City. Salt Lake City is at approximately 40 3/4 degrees north latitude. Directly over your head is at 90 degrees altitude above the horizon and is called the zenith. Your local zenith (altitude 90 degrees) and is equal to the geographical latitude of 40 3/4 degrees north latitude. Near noon on the equinox, the Sun travels directly over the Earth's equator. So, the Sun is 40 3/4 degrees south of your zenith. Thus, the altitude of the Sun on the equinox is 90 - 40 3/4 or about 50 1/4 degrees above your local southern horizon. On the equinoxes, think of the Sun as an over-the-horizon marker of the line of the Earth's equator. At the summer solstice, the apparent tilt of the Sun relative to the Earth's equator increases by 23 1/2 degrees. At Salt Lake City, the apparent altitude of the Sun also increases by 23 1/2 degrees relative to its equinox altitude of 50 1/4 degrees. So on recent summer solstice of June 21 last week, the Sun was at its maximum apparent local altitude of 23 1/2 degrees plus about 50 1/4 degrees or, the total of 73 3/4 degrees. This is about 18 1/4 degrees from the zenith directly above your head. At the last winter solstice on Dec. 22, 2006, the apparent tilt of the Sun decreased by 23 1/2 degrees relative to the equinox altitude of the Sun of about 50 1/4 degrees. In Salt Lake City on the last winter solstice near noon, the local altitude of the Sun above the southern horizon was 50 1/4 degrees minus 23 1/2 degrees, or the difference of 26 3/4 degrees. That altitude was about 63 1/4 degrees from above the zenith above your head. The difference between the Sun's apparent altitude above Salt Lake on the winter and summer solstice (73 3/4 minus 26 3/4) is 47 degrees, or twice 23 1/2 degrees. As the Sun sets around the solstice is a good time to gain a physical appreciation for the path of the ecliptic between the current summer solstice at the north western horizon and its position during the next winter solstice rising at the southeastern horizon. Your hand, held outstretched, provides a convenient means for measuring the angles described above. An outstretched hand, clenched as a fist, marks about 10 angular degrees. That same hand, with the fingers spread wide, marks about 18 angular degrees. Right 90 degrees angles can be measured using two arms outstretched marking the corner of a square. On the equinox, the Sun sets due east and due west. When the Sun sets on the summer solstice, it sets about 23 1/2 degrees north of due west. Facing due south, the celestial equator is traced from due east to about three outstretched spread hands above the due south (50 1/4 degrees altitude) and thence to due west. This point (due south and 50 1/4 degrees altitude) is in the constellation Virgo and is where the Sun will be at then next autumnal equinox during next September. This is about 90 degrees from the summer solstice setting Sun on the northwest horizon. The ecliptic can be traced from the western setting Sun to this point and thence to about 23 1/2 degrees south of due east. Currently at sunset, the bright planet Venus, which is also near the ecliptic, is brightest object in the western sky and can help tracing the ecliptic line from the point of the setting Sun to 50 1/4 degrees above due south. At the next winter solstice, the Sun will be in the constellation Sagittarius, near Scorpio, and is 180 degrees away from the setting summer solstice Sun (at the northwest horizon) along the ecliptic. At sunset Sagittarius and Scropio are rising in the southeast. Sagittarius is about 90 degrees from the position of the Sun at the autumnal equinox in the constellation Virgo. About an hour after sunset (around 10:30pm), the brightest object that you will see in the southeast is the planet Jupiter, now near Sagittarius and also near the ecliptic. Jupiter is near the second brightest object in the southeast sky, the star Antares in Scorpio. When Jupiter crosses due south (around 1 am), it will be about 26 degrees above the southern horizon, or 1 1/2 half outstretched hands. This about the altitude of the winter solstice Sun. Additionally, the distance from the North Pole Star to directly over your head - the zenith - is 90 minus your geographical latitude. This is 90 - 40 3/4 degrees or the difference of 50 1/4 degrees. The angular size of this span remains constant throughout the year. The altitude of the North Star about your north local horizon is equal to your geographical latitude - 40 3/4 degrees - and remains constant throughout the year. When you set up an equatorial mounted telescope at Salt Lake City, this is the angle between the telescope's central polar axis and northern horizon. If you build a sundial with a triangular style, this is included angle of the sundial's triangular style relative to the north horizon. Hope that helps. - Kurt My website on a local sundial that includes further discussion of the altitude of the Sun at the equinoxes and solstices: http://members.csolutions.net/fisherka/astronote/observed/ALSSundial/ALSPag… _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Visit Jerry?
by Patrick Wiggins 24 Jun '07

24 Jun '07

I plan on flying to Kanab Wednesday to have lunch with exo-planet finders Cindy and Jerry Foote and tour their observatories. Anyone care to come along? pw

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-8 is bright!
by Patrick Wiggins 24 Jun '07

24 Jun '07

We had a so-so pass of ISS at SPOC last night but the real hit of the night was a -8 Iridium flare near the zenith. It happened at about 21:41 so the skies were not even completely dark. But it didn't matter, exploding into view right on schedule. We had a lot of public at SPOC and all were watching. You should have heard the screams and applause that greeted the flare. Much fun. Afterwards a kid asked if we could do it again. :) pw

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Last night's overflight
by Barney B. 23 Jun '07

23 Jun '07

Stupid question: In last night's 22:45 pass which was the ISS and which was the Shuttle? Barney

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Scope for sale
by Patrick Wiggins 21 Jun '07

21 Jun '07

Lowell Lyon (bolide(a)sisna.com) is selling a telescope Meade 10” LX200GPSSchmidt-Cassegrain Telescope Includes: 26mm Super Plossl 1.25” O.D. eyepiece 1.25” Diagonal Mirror Runs on 8 “C” batteries or external power. GPS receiver to automatically align telescope. Autostar II Hand Controller for computerized “Go-To” System. Autostar system has over 100,000 objects in database. Mirror lock and zero image-shift microfocuser for astrophotography/ CCD imaging. Ultra High Contract optical coatings included. Sturdy field tripod. Contact Lowell Lyon at 733-7283 or 942-8735$2,700 (or best offer)

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Happy solistice to all
by Kurt Fisher 21 Jun '07

21 Jun '07

Darkness such gets better until Christmas! 2007 Solstices June 21 18 06 Jun. 21, 12:06 PM MDT - Clear Skies - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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ISS and Shuttle overflight wednesday night
by Howard Jackman 21 Jun '07

21 Jun '07

Hey all, I just posted pics of last nights pass by the ISS and shuttle http://www.utahastronomy.com/Howardj?page=4 I happened to get off work early last night and dragged the family out to witness a very cool fly over. The kids were impressed, the wife not so much. Pics aren't great but better than nothing, I think I'll try video next time. The photo of them moving into the earths shadow make them appear to be meteors moving in the opposite direction. Howard ____________________________________________________________________________________ Get the Yahoo! toolbar and be alerted to new email wherever you're surfing. http://new.toolbar.yahoo.com/toolbar/features/mail/index.php

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ISS overflights Thurs, Fri, Sat
by Kurt Fisher 21 Jun '07

21 Jun '07

Thurs. 6/21/07 22h46m32s ISS Appears 22h42m03s 4.3m az:293.8d WNW Transit 22h46m32s 0.0m az:226.2d SW h:19.7 dist:867.4km alt:342.4km Disappears 22h46m57s -0.1m az:213.1d SSW h:19.0d Friday 22 June 2007 21h32m23s ISS Appears 21h27m32s 8.0m az:304.9d NW Transit 21h32m23s -1.9m az:218.0d SW h:75.4d dist:352.0km alt:342.6km Disappears 21h35m31s 0.5m az:132.1d SE h:8.2d Saturday 23 June 2007 21h52m53s ISS Appears 21h48m20s 5.5m az:295.2d WNW Transit 21h52m53s 0.0m az:225.4d SW h:22.2d dist:794.6km alt:342.0km Disappears 21h55m24s 0.5m az:168.8d S h:9.0d _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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RE: [Utah-astronomy] Name of speaker at SLAS meeting?
by Kurt Fisher 21 Jun '07

21 Jun '07

Kurt asked > What was the name of the speaker at last night's SLAS meeting?Bob replied: >> John canizzio [Dr. John Kendall Cannizzo] Thanks, Bob. Great speaker. He works at one of my favorite places: Hearsac! His bio and paper list is at: http://astrophysics.gsfc.nasa.gov/staff/CVs/John.Cannizzo/ 2002-present position -- Research Scientist NASA/GSFC/UMBC/JCA Some Papers: (I believe the ones with "Mattei, J. A." is the former head of the AAVSO (deceased), indicating that Cannizzo has done pro-am collobration in the past.) "The October 1985 Long Outburst of U Geminorum: Revealing the Viscous Time Scale in Long Orbital Period Dwarf Novae" Cannizzo, J. K., Gehrels, N., Mattei, J. A. 2002, ApJ, 579, 760 "The 2001 Superoutburst of WZ Sagittae: A Clue to the Dyanmics of Accretion Disks" Cannizzo, J. K. 2001, ApJ, 561, L175 "The V-EUV Delay for Dwarf Nova Outbursts: A Case Study for VW Hydri, U Geminorum, and SS Cygni" Cannizzo, J. K. 2001, ApJ, 556, 847 "A Study of the Outbursts in SS Cygni", Cannizzo, J. K., Mattei, J. A., 1998, ApJ, 505, 344 Prior positions: 2000-2002--High Energy Astrophysics Group Manager, LHEA, NASA/GSFC/EITI 1994-2000--Research Scientist, Laboratory for High Energy Astrophysics, NASA/GSFC/USRA 1992-1994--Senior NRC Research Associate, Lab. for Astronomy and Solar Physics, GSFC 1991-1992--Alexander von Humboldt Fellow, Max Planck Inst. for Astrophysics, Germany 1989-1991--visiting professor, Department of Physics, Kenyon Coll., OH 1986-1989--research associate/lecturer, Department of Physics, McMaster Univ., ONT 1984-1986--research associate, Department of Astronomy, Harvard Univ., MA - Cleark Skies - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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