"The scientist does not defy the universe. He accepts it. It is his dish to savor, his realm to explore..."

– I. I. Rabi


The following files have been generously contributed over the last several years. They are sorted by category and date. Large files or those that download have file sizes provided.

Waxing crescent moon

Waxing Gibbous Moon

Web Pages
ZIP Files
Acrobat Documents 
Word Documents



M51—The Whirlpool Galaxy (1MB jpg)
As described by Carl Bracken, this image of M51 was taken at the 24-inch Boller & Chivens on Monday, June 22, 2009, around 10:30 p.m. CDT. The conditions were warm and humid but the skies were clear and steady. We used my dad’s DSLR, which is a Canon EOS 5D that sports a 12.8 megapixel sensor (at 35.8mm x 23.9 mm, it is considered a full size sensor.) We ran the camera at ISO 800 using a wired locking bulb remote to open the shutter and the camera was set to store Canon raw images or CR2 files which averaged 10+MB each. The attached jpeg images are downsized from the original full resolution (these files are 2193 x 1460.)

We attached a 15” LCD monitor to the camera—which we used to review images after the shutter was released—to find focus. We ran a series of ever-increasing exposure durations up to 500+ seconds. I made sure to take a couple of same duration images with the bypass mirror covering the sensor which I planned to use as dark frames. Earlier in the evening I also took some 1-second images which turned out useful for bias frames. I loaded all of the best images into MaxIM which can handle the CR2 files directly (so can Registax Ver 5!) I simply applied some basic frame subtraction and calibration to arrive at the finished product which clearly shows the spiral arms of M51. Posted 6-27-09

Northern Lights in December
Some gorgeous images of the aurora borealis (the downloadable ZIP file is about 4MB and contains three images) as photographed by Alan Atwood on the night of December 14–15. Posted on 12-18-06

Rockwell Collins Retirees Newsletter
Scanned image of April newsletter featuring EIOLC. Contributed by Dick Plasencia. Posted 04-24-06

Spectrum of α Aquilae (Altair)
Color spectrum showing hint of absorption lines. Taken with a hand-held digital camera. Posted 08-09-05

Image of Jupiter 
This image was taken by CAA member Alan Atwood using his telescope and the new Meade LPI CCD camera. Posted 5-24-05

Third Annual Iowa Convention of Amateur and Professional Astronomers(1.0 MB)
Group photo of attendees to the convention hosted by the CAA less than a year after the society's founding. Members from Cedar Rapids, Dubuque, Des Moines, Marshalltown are seen as are others, including our keynote speaker, Dr. James A. Van Allen of The University of Iowa. Contributed by Doug Slauson.
Posted 3-28-05

December 21, 2004 Machholz Mosaic 
Mr. Glinch has been at it again, this time posting a mosaic of images that show structure in the tail of the Comet Machholz. Posted 12-30-2004

December 14, 2004 Picture of Comet Machholz (210 kB) 
Gary Clinch has been photographing Comet Machholz, and has a nice image available here. Posted 12-15-2004

Aurora Photo by Heinz Blankenhagen 
Heinz also contributed a nice picture from the Sunday, November 7, 2004 auroral display. The photo was taken with a Nikon F3, fl 35mm at F2.8 with a 2 minute exposure. Posted 11-10-2004



Fr. Kemble's Procedure for Celestial Pole Alignment 
Web link to Fr. Lucian Kemble's procedure hosted by the Calgary Centre of the Royal Astronomical Society of Canada. This procedure also includes a variation to allow "daytime" polar alignment of your telescope's equatorial mount. Posted 07-14-05



PowerPoint Slide 
A slide for inclusion in CAA PowerPoint presentations regarding the joint relationship between the CAA and the Linn Country Conservation Commission. Contributed by Dennis Goemaat of the L.C.C.C. Posted 07-12-05

Adobe Acrobat File
Slides from Jim Jezek's July 14 presentation on tracking artificial satellites with active links. Contributed by Jim Jezek. Posted 07-15-07.



Eyepiece Analysis (30kB)
This Microsoft Excel spreadsheet computes relevant parameters of telescope eyepieces. Submitted by CAA member Jeff Finley.
Posted 5-16-05



Boller & Chivens photos (mount support) 
This .zip file has three pictures Gerry sent in that illustrate some of the issues regarding mounting support for the B&C scope.
Posted 12-30-2004

November 7, 2004 Aurora Photos by Alan Atwood (454 kB) 
Check out Boomer's photos of the big aurora storm on Sunday, November 7, 2004. Posted 11-10-2004

Lunar Pictures by Jerry Warner (160 kB) 
Lunar photos taken 24-Oct-2004. Jerry comments: "I shot these Sunday night using the 6" f/15 refractor, 5" f/5 refractor piggy backed on the C16, and the Meade LX-200. All at prime focus using an 840 ToUCam. Conditions were very turbulent. These are all unstacked unprocessed raw frames. I just selected some of the better frames that came out."
Posted 10-27-2004

Celestron-16 Optical Performance and Collimation (235 kB) 
A set of pictures contributed by Jerry Warner that show the optical performance of the society's C-16 over a 3-hour cool down period. See this link (Yahoo group members only) for details.
Posted 10-6-2004

Meade LX-200 Optical Performance and Collimation (368 kB) 
A set of pictures contributed by Jerry Warner that show the optical performance of the society's 16-inch LX-200 over a 3-hour cool down period. See this link (Yahoo group members only) for details. Posted 10-5-2004



An opinion from KCCK's Dennis Green about Iowa Public Radio 
An article by Mark Jayne from KCCK addressing the movement within the state of Iowa to convert radio stations such as KCCK into a network of radio stations called Iowa Public Radio.
Posted 12-20-2004



Shooting NGC 7331 (751 kB) 
Another night of astrophotography related by Gary Clinch. He starts off targeting Stephen's Quintet, but winds up with a great picture of NGC 7331.
Posted 12-15-2004

Nicknames of Planetary Nebulae
A list of common nicknames for over 120 planetary nebulae, along with notes on the origins of many of the names. Created by Kent Wallace, Revision 2, September 23, 2004. Posted 9-24-2004

Pluto Challenge (689 kB) 
Gary Clinch's quest to photograph the Solar System's smallest, most elusive planet. Posted 9-2-2004