Tracing Luminaries: Plate No. B20645 (Small Magellanic Cloud)
Edition of 8
One of a portfolio of six gilded intaglio prints with chine collé. These prints were editioned from laser engraved cast acrylic plates, inked with transparent base, and then printed onto a starlight-exposed cyanotyped Okuwara collé on Hahnemühle Copperplate. The image was then revealed with 24 karat gold leaf.
Observatory: Harvard Boyden Station, Arequipa, Peru
Telescope: 8-inch Bache Doublet, Voigtlander, reworked by Clark
Date Exposed: 19 October 1897; Exposure: 133 minutes (?)
Right Ascension: 0 hours 5 minutes (?); Declination: -74.1 degrees (?)
Class: L; Quality: 4
Plate Events: Marks removed, likely around 2009-02-03T14:34:05; Plate not scanned for DASCH; Plate was added to The Williamina Fleming Collection, a collection created to preserve around 600 marked plates, even though the marks from this plate had been removed.
Marked by: This plate was marked by Henrietta Swan Leavitt and possibly her assistants.
Curatorial & Astronomical Notes: This plate was used in Henrietta Swan Leavitt’s 1908 groundbreaking paper titled, 1777 Variables in the Magellanic Clouds, which compared Cepheid variable stars, and eventually led to her far-reaching discovery of the period-luminosity relationship. This plate number is noted on pages 9 (13 April), 19 (14 April), 31 (15 April), 37 (17 April), 49 (18 April), 54 (18 April), 67 (19 April), 87 (25 April), 94 (27 April), 108 (28 April), 110 (29 April), 112 (29 April), 117 (10 May), 131 (16 June), 150 (04 October) in Leavitt’s 1905 notebook.