The Development of Techniques for the Extension of the Magnitude Scale in Selected Equatorial Kapteyn Areas with an Image Orthicon System.

Abstract

The development of the image orthicon into a viable photometric tool is discussed along with the limitations of its effectiveness. It is shown that the image orthicon is capable of stellar photometry with probable errors in magnitude of 0.05. Using a 24-inch f/10 Cassegrain at the Corralitos Observatory in New Mexico, the image orthicon gave repeatable results over an eight magnitude range down to the 18th magnitude with three-second integration times. Reduction curves connecting image diameters with visual magnitudes were derived using standard magnitudes of Sandage and Eggen for stars in NGC 188 for calibration. This photometric technique is particularly adaptable to photometry of an entire field of objects. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1976
Accession Number
ADA030506

Entities

People

  • Edward J. Weiler
  • J. Allen Hynek
  • Justus R. Dunlap

Organizations

  • Northwestern University

Tags

DTIC Thesaurus Topics

  • Calibration
  • Diameters
  • Image Orthicons
  • New Mexico
  • Observatories
  • Photometry
  • Standards

Fields of Study

  • Physics

Readers

  • Aerospace Test and Evaluation
  • Astronomy/Astrophysics
  • Systems Analysis and Design