George H. Fisher
Space Sciences Laboratory # 7450
University of California
Berkeley, CA 94720-7450
U.S.A.
Phone: (510) 642-8896
Fax: (510) 643-8302
email: fisher@ssl.berkeley.edu
vita:
An image of the Sun viewed in an FeXII line formed at temperatures
of 106K. The image was taken from the
EIT
telescope on the
SOHO
spacecraft on Aug. 26, 1996.
It shows a large active region (the bright area toward the lower left) and
a coronal hole (the dark irregular shape)
extending from the north pole to an area adjacent to
the active region. Magnetic fields in coronal holes are open and the plasma
can escape freely,
while magnetic fields elsewhere are closed, trapping the hot plasma.
Current Images of the Sun
RESEARCH INTERESTS
The physical origin of magnetic fields on the
Sun
and other cool stars
remains one of the most important, yet least understood phenomena in
astrophysics. It is also a timely research topic, since it is now
known that magnetic activity changes the Sun's luminosity and
ultraviolet flux, both of which may have significant effects on the
terrestrial environment.
In our research group, we investigate a number of topics relating
to the emergence of magnetic flux on the Sun and its consequences, including
the formation of active regions, heating of the Solar corona, and the
origin of Solar flares. We use both theoretical and observational
approaches in our studies, including analytical work, numerical simulations,
and the analysis of exciting new spacecraft data, such as that from
the Soft X-ray Telescope
on the Yohkoh spacecraft, and from the
SUMER
UV spectrograph on the SOHO
spacecraft. The detectors for several of the instruments on SOHO were
built by members of the
Experimental Astrophysics Group (EAG) here at Berkeley.
RESEARCH SUMMARY: 1997-1998
Recent Talks:
Recent Publications:
Other Solar Group Members:
Chris Johns-Krull,
Bill Abbett,
Jim McTiernan,
Mark Linton,
(now at Naval Research Lab),
Dana Longcope
(also Montana State University),
and Tod Woods
(also LLNL).
Outreach Material on Sunspots and Solar Activity
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