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Moon's light with a selenium photometer
Graph of the moon's brightness with phase from the first application of the selenium cell photometer.
National Historic Landmark plaque
The University of Illinois Observatory is historically significant for the development of selenium and photoelectric cell photometry that revolutionized the measurement of celestial magnitudes. The determination of stellar magnitudes is one of the…
Photoelectric photometer filters
Wood, metal, glass
Small wooden box (4 ¾ x 2 ¾ x 2”), 11 shades, some marked .66, .86, 1.31, 1.56, 1.80, 2.95, 4 unlabeled. Possibly 1917.
Made reference to use of shades in several papers including Nova Aquilae and Algol (1921).
Small wooden box (4 ¾ x 2 ¾ x 2”), 11 shades, some marked .66, .86, 1.31, 1.56, 1.80, 2.95, 4 unlabeled. Possibly 1917.
Made reference to use of shades in several papers including Nova Aquilae and Algol (1921).
Photograph 'Photoelectric photometer'
Photograph of the photoelectric cell photometer attached to the 12-inch refractor. The photograph dates to about 1913-1915. During the summer of 1915, Dr. Stebbins took this photometer to Lick Observatory to study the variable star Beta Lyrae.…
Photograph Ross Camera and Fauth finderscope
Photograph of the 4-inch Ross-Fecker camera with the 4-inch Fauth refractor as the finderscope.
The instrument was a refractor of 4-inch aperture and 28-inch focal length (f/7) with a scale of 290”/mm. It held 8x10 inch glass plates covering 20…
The instrument was a refractor of 4-inch aperture and 28-inch focal length (f/7) with a scale of 290”/mm. It held 8x10 inch glass plates covering 20…
Plate camera
Wood, brass
Wooden box (9 ½ x 9 ½ x 9) with hinge lid, two film holders, several 3-inch x 3-inch glass filters. The plate camera is an original piece of equipment made by Warner and Swasey. It takes 2 ¼-inch by 3 ¼-inch glass plates or sheets of…
Wooden box (9 ½ x 9 ½ x 9) with hinge lid, two film holders, several 3-inch x 3-inch glass filters. The plate camera is an original piece of equipment made by Warner and Swasey. It takes 2 ¼-inch by 3 ¼-inch glass plates or sheets of…
Post card 'Radio telescope at the Vermilion River Observatory'
Post text: "Radio telescope at the Vermilion River Observatory, University of Illinois. Giant radio telescope 600 feet long, 400 feet wide. A wire mesh on the surface reflects cosmic signals to 274 antennas on the wooden truss, 153 feet high. It is…
Post card 'View of South Campus University of Illinois'
Color postcard from 1914 showing the south campus. Taken from University Hall looking south. Burrill Avenue is under the trees long the center right. The Auditorium is center. The Observatory is the white dome to the left of the Auditorium.
Postcard "Observatory"
Looking south toward the north entrance of the Observatory. The transit telescope is visible in the window of the western most transit room. This transit telescope had an objective of 2-inch diameter and was made by Newton & Company of London,…
Postcard, "Observatory, University of Illinois"
Looking southwest toward the north entrance of the observatory.