AN ABSOLUTE ISOPHOTOMETRY OF THE SOUTHERN MILKY WAY AND TWO FIELDS IN ORION

Abstract

THE FORM AND ABSOLUTE BRIGHTNESS OF THE SOUTHERN MILKY WAY ARE REPRESENTED BY MEANS OF ISOPHOTAL CHARTS IN 3 PASSBANDS. ONE OF THE PASSBANDS IS CENTERED ON H(ALPHA) AND ANOTHER NEAR H(BETA) SO THAT STRONG EMISSIONS OF H II REGIONS ARE SELECTED; THE THIRD PASSES A YELLOW CONTINUUM SERVING AS A STANDARD NEARLY FREE OF NEBULAR EMISSIONS. THE ISOPHOTAL CHARTS SHOW 78 FIELDS, EACH 11.5 DEGREES IN DIAMETER ALONG 182 DEGREES OF THE MILKY WAY;THE CENTERS LIE ROUGHLY 7 DEGREES APART ONTHE GALACTIC EQUATOR. TWO MORE FIELDS ARE CENTERED ON ORIONIS (THETA AND LAMBDA). EACH CHART SHOWS A FIELD IN 3 PASSBANDS CENTERED NEAR 6560A IN THE UPPER LEFT, 4810A IN THE LOWER LEFT, AND 6070A ON THE MIDDLE RIGHT. THE PLATES FOR THE CHARTS WERE TAKEN WITH A 8-IN. F/1 FIELD FLATTENED SCHMIDT CAMERA;A TUBE SENSITOMETER EXPOSED SPOTS ON THE MARGINS OF THE PLATES. THE ISOPHOTES WERE TRACED FROM ENLARGEMENTS OF THE PLATES, ON A SAMPLE ANALYSIS IS MADE OF THE H II REGION AROUND ETA CACARINEA IN ORDER TO SHOW PROBLEMS ARISING WITH THE USE OF THE CHARTS

Document Details

Document Type
Technical Report
Publication Date
May 01, 1960
Accession Number
AD0250596

Entities

People

  • Hugh M. Johnson

Organizations

  • Australian National University

Tags

DTIC Thesaurus Topics

  • Brightness
  • Cameras
  • Diameters
  • Emission
  • Photography
  • Physical Properties
  • Sensitometers
  • Standards

Fields of Study

  • Physics

Readers

  • Astronomy/Astrophysics
  • Space/Atmospheric Physics.