The Sperling Files: Overexposures for Discovery and Fame

Norman Sperling

(c) 2002 Norman Sperling. Excerpted with permission from "What Your Astronomy Textbook Won't Tell You" (ISBN 0-913399-04-3).

Imaging technology is rapidly improving and cheapening. From current astrophotography guides, determine “recommended” exposures for accessible deep-sky objects. Then take time exposures that are many times longer than the recommended amount - up to the sky-fogging limit. That should grossly overexpose the inner parts, but what will you discover beyond them?

This may reveal new structures, some of which have different shapes than the brighter components. Some may show nothing new - itself noteworthy. And all the ones that do show something new are worth drawing scholarly attention to. Please send me a copy of any interesting results.

Tony and Daphne Hallas photographed M57, showing a larger loop of faint old gas beyond the Ring. Their photo of part of M13 shows gazillions of stars all the way out to the edge of the photo, and presumably beyond.

Now apply the same technique to elliptical galaxies. Some galaxies presently catalogued as ellipticals may actually be the bulges of disc galaxies, whose discs have not yet been noticed.

I suspect that at least one will reveal a hint of a Population I disc outside the elliptical (= bulge), showing that that galaxy is really spiral rather than elliptical.

Important discoveries await serious amateur astronomers. All it takes is really deep overexposures.

Norm Sperling is editor of The Journal of Irreproducible Results. Previously he was assistant editor of Sky & Telescope magazine and Science Editor at AltaVista.com. Norm teaches astronomy in universities around San Francisco, wrote the new book "What Your Astronomy Textbook Won't Tell You," and co-designed Edmund Scientific's Astroscan telescope.