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Solar spectroheliograph image, Yerkes Observatory, WI, circa 1915

Subjects
Cameras & PhotographySchools & Universities
Card type
Printed photo
Date
c. 1915 (White Border)
Front of Solar spectroheliograph image, Yerkes Observatory, WI, circa 1915, c. 1915 printed photo postcard
Front
Back of Solar spectroheliograph image, Yerkes Observatory, WI, circa 1915, c. 1915 printed photo postcard
Back

About this postcard

The image combines two solar photographs to show brilliant areas and eruptions of calcium vapor. The caption gives the Sun's diameter as 865,000 miles and credits the spectroheliograph at Yerkes Observatory of the University of Chicago. Yerkes opened in 1897 at Williams Bay, Wisconsin, as the University of Chicago's observatory. Its spectroheliograph photographed the Sun in narrow wavelengths, revealing features of the solar atmosphere that ordinary white-light views could not. The caption's "eruptions of calcium vapor" uses period language for bright calcium features in the Sun's atmosphere.

Postcard Details

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PublisherGrogan Photo System, Inc.
A combination of two solar photographs showing brilliant areas and eruptions of calcium vapor. The sun's diameter is 865,000 miles. Taken with the spec- troheliograph of the Yerkes Observatory of the Uni- versity of Chicago.
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Postcard record

PublisherGrogan Photo System, Inc.
ConditionGood
Place mentionedYerkes Observatory
Place mentionedUniversity of Chicago, Chicago, IL
PublisherGrogan Photo System, Inc., Milwaukee, WI
NotesWhite border; black-and-white printed image with caption below; light age toning and a few small stains. No postmark. Divided-back card with matte finish and white border; printed imprint "Post Card / GROGAN PHOTO SYSTEM, INC. MILWAUKEE". Pencil dealer marks along right edge ("#733" / "CO. 1/8"), not correspondence.

Cite this card

Solar spectroheliograph image, Yerkes Observatory, WI, circa 1915, postcard, c. 1915. PostalPast Collection. https://postalpast.com/postcard/solar-spectroheliograph-image-yerkes-observatory-wi-circa-19. Accessed November 3, 2026.