HUT Observatory

Reenactment of Lewis M. Rutherfurd’s Solar Observation

JWB & JWH & Rutherfurd at McMath-Pierce KPNOIn September of 2012, J. W. Briggs transported the 13-inch Rutherfurd refractor, built in 1868 and originally used by pioneering New York astronomer Lewis M. Rutherfurd, from Eagle, Colorado, to Kitt Peak National Observatory near Tucson, Arizona.  Teaming there with Dr. Jack Harvey of the National Solar Observatory scientific staff (shown here on the right), Briggs consummated a suggestion made years before by Harvey — that they attempt to reenact Rutherfurd’s reported 1871 photographic observations of solar granulation.  The large tube assembly was carried into the huge McMath-Pierce Solar Telescope facility (here in the background) and mounted vertically in a sunbeam.  The Rutherfurd telescope focused the Sun onto both modern electronic detectors and onto such increasingly rare 8×10-inch-format film as friends at Kitt Peak made available.  A video webcam link allowed other interested friends to follow the activity across the country.

 

Cropped poreA final write-up is in process, but the highly magnified electronic image shown here testifies for the quality of Rutherfurd’s old optics.  Harvey and Briggs are hoping that an early copy of Rutherfurd’s granulation photograph, given to the Royal Astronomical Society in England, can be located to reveal exactly how his early photographs resolved the Sun.  The closest known surviving original solar photograph by Rutherfurd differs by one day from the date associated with his granulation photography.  Most historians credit the French astronomer Jules Janssen with the first photographic record of granulation, but the great American astronomer and astrophotographer, Edward E. Barnard, defended Rutherfurd’s claim (made modestly) that he, in fact, was the first.  We may never know the merits with certainty.  But the effort to learn more has been very interesting.

Below is a rare view from the top of the McMath-Pierce Solar Telescope.  An 84-inch-diameter flat mirror, mounted equatorially in an inverted horseshoe on the left, captures and directs a sunbeam downward toward the south celestial pole.  Far below is a quad-cab pickup truck and 14-foot trailer used to transport the antique telescope for the experiment – here dramatizing the impressive height of the McMath-Pierce above Kitt Peak.

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