ATST: A New Solar Telescope for a New Century
by Jeff Kuhn
A conceptual design of ATST. The final design has not yet
been determined. Source: http://atst.nso.edu
IfA scientists are participating in a project to design
and develop the next-generation solar research telescope called the Advanced
Technology Solar Telescope (ATST). This instrument represents the largest
single advance in ground-based solar observing since the time of Galileo! The
project is being funded by the National Science Foundation (NSF).
Why We Need the ATST. Changes on the Sun directly affect
the climate here on Earth. These can be small, short-term changes lasting but a
few years, or they can be long-term changes over thousands of years. There is
no doubt that in the past the Sun caused climate changes that make current
trends in global warming look mild.
With technology that is now available, scientists do not
understand, and cannot predict, what will happen on the Sun and how it will
affect Earth, even over the next decade. The ATST will enable them to measure
changes in the Sun's magnetic fields and determine how these changes affect the
solar system environment between Earth and the Sun.
Project Participants. The effort to design and develop
the ATST is centered at the National Solar Observatory (Tucson, Arizona) and
Sacramento Peak Observatory (New Mexico). The co-investigator institutions for
this activity are the University of Hawaii, the University of Chicago, the High
Altitude Observatory in Boulder, and the Big Bear Solar Observatory (of the New
Jersey Institute of Technology). At IfA, solar scientists Jeff Kuhn (lead),
Haosheng Lin, and Donald Mickey, and instrument scientist Roy Coulter are
working on this effort.
A total of 22 institutions are participating in the
design and development phase of the project in some way. Toward the end of
2004, this phase will culminate in the presentation to NSF of a detailed plan
for locating and building the ATST facility.
What will the ATST look like? The ATST telescope will be,
by far, the largest solar telescope ever built. With a primary mirror diameter
of 4 meters (13 feet) and a unique off-axis telescope design, it will have
enough resolution and collect enough solar radiation to allow scientists to see
and measure the magnetic structures within the solar atmosphere.
The telescope design is unusual in that the light does
not pass by or near to the secondary mirror in its path to the primary. A small
prototype version of the ATST telescope called SOLARC (Scatter Free Observatory
for Limb Active Regions and Coronae) is already operating on the summit of
Haleakala. This NASA-funded instrument has been useful both for advancing solar
coronal research in its own right and as a working facility for testing ATST
design and engineering concepts.
This image shows one of the first observations
SOLARC revealing the complicated structure of a sunspot when it is seen with
resolution possible from Haleakala.
Where will the ATST be built? Many who have studied the
possible locations for this telescope believe that there is no better place in
the world for it than the summit of Haleakala. If built there, it will have the
greatest scientific impact. With care and proper planning, this can be
accomplished without negative environmental or cultural impacts on the mountain
summit. IfA scientists are now collecting and monitoring atmospheric conditions
on Haleakala in preparation for the ATST siting decision.
As a national scientific institution, the ATST project
will benefit from the scientific and technical infrastructure that the
Institute for Astronomy, the University of Hawaii, and the state of Hawaii can
provide. In return, the state will benefit because ATST will bring an influx
of federal funds, high-paying jobs, and educational opportunities, and will
the state's profile as a place where successful scientific and high-technology
projects occur. While the design is not finalized, it is likely that the ATST
will be a $100 million facility.
For more information: http://atst.nso.edu