AAVSO: American Association of Variable Star Observers

Digitizing Olin Eggen's Card Database

Volume 45 number 1 (2017)

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Jack Crast
1784 Lisle Rd, Owego, NY 13827; jackcrast@gmail.com
George Silvis
194 Clipper Rd, Bourne, MA 02532; SGEO@GASilvis.net

Abstract

The goal of the Eggen Card Database Project is to recover as many of the photometric observations from Olin Eggen’s Card Database as possible and preserve these observations, in digital forms that are accessible by anyone. Any observations of interest to the AAVSO will be added to the AAVSO International Database (AID). Given to the AAVSO on long-term loan by the Cerro Tololo Inter-American Observatory, the database is a collection of over 78,000 index cards holding all Eggen’s observations made between 1960 and 1990. The cards were electronically scanned and the resulting 108,000 card images have been published as a series of 2,216 PDF files, which are available from the AAVSO web site. The same images are also stored in an AAVSO online database where they are indexed by star name and card content. These images can be viewed using the eggen card portal online tool. Eggen made observations using filter bands from five different photometric systems. He documented these observations using 15 different data recording formats. Each format represents a combination of filter magnitudes and color indexes. These observations are being transcribed onto spreadsheets, from which observations of value to the AAVSO are added to the AID. A total of 506 U, B, V, R, and I observations were added to the AID for the variable stars S Car and l Car. We would like the reader to search through the card database using the eggen card portal for stars of particular interest. If such stars are found and retrieval of the observations is desired, e-mail the authors, and we will be happy to help retrieve those data for the reader.