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The Multi-Spectral Solar Telescope Array, MSSTA (128 kb GIF
image), is a telescope array consisting of at least fifteen different telescopes
designed to observe the Sun in ultraviolet and soft x-rays. The project is part of a joint
effort between Richard Hoover at MSFC and Art B. C. Walker at Stanford University. Each
telescope in the array consists of mirrored optics coated with multilayers to allow for
reflection at a selected wavelength. Pre-filters are used to exclude unwanted emissions so
that each telescope obtains images at its prescribed wavelength.
MSSTA's first flight was on May 13th, 1991 at 19:03 UT. The payload was launched from
White Sands Missile Range atop a Terrier Black Brant IX (283 kb
GIF image). The telescopes were carried to an altitude of 230 km and remained out of
the lower atmosphere for approximately 6 minutes. During this time photographs were taken
of the Sun and its outer atmospheric layers, the chromosphere and corona.
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Images obtained with MSSTA span the wavelength range from Lyman-Alpha emission at 1216
Å to a Si XII emission line at 44 Å. Among these images are:
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H I 1216 Å
(152 kB GIF image) Temperature = 20,000 K
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He II
304 Å (134 kB GIF image) Temperature = 80,000 K
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Fe XII
193 Å (88 kB GIF image) Temperature = 1,500,000 K
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Fe XIV
211 Å (81 kB GIF image) Temperature = 1,800,000 K
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Si XII
44 Å (94 kB GIF image) Temperature = 2,000,000 K
Ground-based images taken at nearly the same time were acquired from the Big Bear Solar
Observatory (BBSO) and the National Solar Observatory (NSO). These images include:
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BBSO
White Light (141 kB GIF image) Temperature = 6,000 K
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BBSO H
I 6563 Å (76 kB GIF image) Temperature = 10,000 K
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BBSO
Ca II 3934 Å (79 kB GIF image) Temperature = 10,000 K
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NSO
Magnetogram (64 kB GIF image)
Analysis of these images is in progress. These analyses will help to determine
temperatures and densities in the observed coronal structures and provide information on
magnetic connections between them.
A reflight of the MSSTA payload with several new instruments took place on November
3rd, 1994.
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