Solar Maximum Mission (SMM) Coronagraph/Polarimeter Data

The instrument consists of an externally occulted coronagraph and linear polarimeter with a meshless SEC vidicon as a detector. Spatial resolution in the outer corona is 10 arc-sec, set by the vidicon pixel size. Exposures of 8-second duration yield good images with the green filter (5014-5328 A band).

A complete Polaroid sequence requires 7 min. The field of view is approximately square, with a side length corresponding to approximately 5.6 solar radii. The instrument operated from the spacecraft launch, Feb. 14, 1980, until Nov. 24, 1980, when operations were interrupted by failure of the spacecraft fine pointing control.

In April, 1984, Challenger Shuttle astronauts restored the SMM fine pointing capability, and C/P observations resumed until loss of pointing on Nov.17, 1989. Data sets exist in several locations. Recent data, catalogs and special selected data sets are held at the SMM Data Analysis Center, NASA/GSFC.

The primary analysis and archive center is at the High Altitude Observatory, NCAR, where many reduced and analyzed data products are held. Some data have been deposited at NSSDC. Requests for further information or specific data should be made initially to the SMM DAC or to HAO. 'A Catalogue of Mass Ejections Observed by the Solar Maximum Mission Coronagraph', (St.

Cyr, O.C., Burkepile 1990) includes events observed from March 7, 1980 - September 23, 1980, and, after the in-orbit repair by the Challenger, from June 8, 1984 until November 17, 1989. The catalogued events were defined as observable changes in coronal structure occurring on a time-scale between a few minutes and several hours, involves the appearance of a new, discrete, bright, white-light feature which displays a predominantly radial outward motion through the field of view.

Detailed information on individual events will be made available upon request by the Primary Investigator, Dr. Hundhausen. The NSSDC 80-014A-01B data set consists of 35 mm images of the solar corona on 100-ft. reels, made by transferring the digital output of the C/P vidicon array (levels from 0-255) to film with a Dicomed recorder.

Two of the instrument's filters were used to make the digital images, a green broadband filter (5000-5305A) and an H-alpha filter (6543-6583A). Pairs of sequential images made with each of these two filters are found in chronological order on the reels. In using this set, reference should be made to the following user's guide documents: 'Guide to 1980 SMM Coronograph/Polarimeter 35 mm Images'; 'C Data Analysis Guide.'