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The Webfooted Astronomer - August 1999


AstroCon 99--A Good Show!

by Joanne Green

Picture a small Eastern Washington town nestled among gently rolling hills. This is Cheney, home of Eastern Washington University, nearly deserted in summer. Looking from our 8th floor dormitory window we watched the wind rippling through the standing grain at the edge of the campus, saw a single car move slowly along the campus street as we got ready to walk to the Student Union building where the day’s AstroCon activity would take place.

It was the week of July 13-17. Pat Lewis and I were among nine or so people from the Seattle and Everett area, including Al MacFarlane (who gave talks on Video Astronomy), Ed Mannery (who gave talks on the Sloan Digital Sky Survey), Bob Suryan, Jeff Mo bley (vending for Captain’s Nautical), Mary Ingersoll, Mark Folkerts (President of the Everett club), and Jim Bielaga (vending for Anacortes Telescope and Wild Bird).

Each day there were six hours with three or four lectures or workshops to choose from each hour. A children’s workshop included making a Dobsonian, planetarium shows, and a hands-on comet and meteor workshop put on by the Pacific Science Center. Project A stro volunteers were preparing for their classroom activities back home.

Special Events included a presentation by Bill Nye the Science Guy and a "Bus Tour to Mars" tour of the channeled scablands, with Dry Falls and Grand Coulee, remnants of gigantic ice-age floods that swept the soil and produced a devastated area akin to some formations on Mars. [See Mary Ingersoll's article later in this issue for more on the Bus Tour to Mars.—-Editor]

A popular event was the appearance of former astronaut Story Musgrave, who showed rare pictures taken during his space shuttle flights, including pictures showing the repair of the Hubble Space Telescope, and Earth sunsets and landforms from 400 miles up.

There were several opportunities to view the skies with telescopes. A dark sky site a mile away from town was a fair experience, though unseasonably cold for July this year, according to Mark Folkerts and Jim Bielaga. (Imagine a dark site a mile away f rom Seattle!)

David Malin, Astrophotographer Supreme
Especially interesting were the two talks by David Malin of the Anglo-Australian Observatory at Siding Springs Mountain in Australia. You may have seen his stunning photographs in his book, A view of the Universe. (A second book is due to be released in t he fall of 1999) Malin’s photography and dark room methods have yielded beauty, but more important for astronomy, he has produced images that suggest answers to many current investigations. The use of “unsharp masking” is one way to get more detail out of a negative. By superimposing a blurred positive on the original negative, most of the coarse detail is cancelled revealing fine detail previously hidden in the original negative.

Another way of revealing details is called photographic amplification, which is done by making separate positive film copies from the negative and combining the positives to print a single image. Combining the images enhances the weak images and shows things previously hidden. Related to this is photographic subtraction. By such methods, Malin uncovered many unseen details, such as faint shells of stars around some elliptical galaxies and around Centaurus A; material protruding from galaxy M89 in Virgo (probably another galaxy interacting with it); and a series of pictures showing light “echoes” proceeding outward from around supernova 1987A. He discovered Malin-1, a faint proto-galaxy in the Virgo cluster.

Instead of exposing color film, Malin exposes black and white film with colored filters. One plate is exposed with a red filter, a second plate is exposed with a green filter, and a third plate with a blue filter. The three negatives are then used to p rint the object on color printing paper. Today there is a tendency to abandon film photography in favor of CCD work, as if the only way to do astronomy were to wiggle your fingers over computer keys. Although Malin has produced many photos of great beauty, his job is a research job and as long a s film photography yields scientific information, he will continue using it. He uses CCD photography in much of his work. "But," says David Malin, "you need film if you want to get pictures that will blow your socks off!"

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