|Instrument: VECTOR MAGNETOGRAPHS|
Solar/Space Observing Instruments
Instrument Class: Magnetic Field/Electric Field Instruments
Instrument Type: VECTOR MAGNETOGRAPHS
Related Data Sets
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The MSFC magnetograph was developed in the early 1970s and has been operating
as a vector system since 1976 in support of NASA space missions (Solar Maximum
Mission and Spacelab), rocket and balloon experiments, and joint ground-based
observations. The magnetograph consists of a symmetric 30-cm Cassegrain
system which has a field of view of 6 x 6 arc-min giving an effective pixel
size of 2.8 x 2.8 arc- sec in the 2 x 2 pixel-binning mode of the CCD camera.
The absorption line Fe I 5250.2 is selected by a Zeiss birefringent filter
(FWHM = 0.125A). The polarimeter consists of quarter-wave plates, a KD*P
electro-optical modulator, and an analyzer provided by the sheet polarizers in
the Zeiss filter. The resulting magnetic field sensitivities are 5 and 125 G
in the line-of-sight and transverse components, respectively, with a temporal
cadence of 5 min.
The Zeiss filter can be tuned +/- 8 Angstroms about the Fe I 5250.2 line.
This allows the three Fe I lines at 5247.0, 5250.2, and 5250.6 to be selected
for performing flux tube analyses. Information on the method of calibration
used for the interpretation of MSFC vector magnetograph data can be found in
NASA TM-4048, 'The SAMEX Vector Magnetograph - A Design Study for a Space-
Based Solar Vector Magnetograph' (M. J.Hagyard, G. A. Gary, and E. A. West,
The capabilities of the MSFC vector magnetograph were extended in September
1989 by the addition of a coaligned H-alpha telescope with a CCD camera.
This telescope was the engineering-backup model of the Skylab ATM H-alpha 1
telescope. The system is a 17-cm Cassegrain which feeds a Fabry-Perot filter
with a 0.7 A bandpass. The H-alpha system provides video images of chromosphe-
ric activity that are cospatial and cotemporal with the vector magnetograms.
Research programs carried out with the coaligned instruments include studies
of magnetic morphology, evaluation of magnetic shear at flare sites,
calculation of vertical electric currents, analysis of magnetic field
submergence/emergence, studies of magnetic canopies, evaluation of magnetic
energy, coronal field extrapolations, Stokes profile analysis, and the study
of magneto-optical effects.
Because the MSFC magnetograph is a dedicated system, the MSFC team can observe
each day that weather permits. The observational data are reported in: 'The
MSFC Solar Observatory Report,' (published twice a year and distributed to the
For further information on the MSFC Solar Vector
Magnetograph, link to the web at