Observing The Sun With Three New Instruments
The Astronomy and Astrophysics Survey Committee recommends three moderate initiatives, two ground-based and one space-based, to study the Sun's internal structure and dynamics,its changing magnetic fields, and the relationship between these solar aspects and the Sun's effects on Earth.
THE ADVANCED TECHNOLOGY SOLAR TELESCOPE (ATST) WILL TRACE THE SUN'S DYNAMIC MAGNETIC FIELD
First among these recommendations,the ground-based Advanced Technology Solar Telescope (ATST) will have a 4-meter mirror with adaptive optics capable of obtaining far more detailed visible-light solar images than any now available. These images will allow astronomers to test and to refine their theories of how the Sun generates the magnetic fields near its surface and how these fields affect the hot plasma gas above the surface. ATST will have international partners that will join the United States in applying the recent advances in adaptive-optics systems and large-format infrared cameras to solar astrophysics.
THE SOLAR DYNAMICS OBSERVATORY (SDO) WILL PEER INTO THE SUN'S PULSATING INTERIOR
To study the region below the solar surface, the space-borne Solar Dynamics Observatory (SDO) will improve on the highly successful Solar and Heliospheric Observatory (SOHO). SDO will move in a geosynchronous orbit, making continuous solar observations through the entire ultraviolet and visible-light spectral domains, as well as the shortest-wavelength portion of the infrared. With this capability, SDO will help to determine the origin of sunspots, transient regions on the solar surface that have a temperature 1,000 degrees below the average (apparently because of the localized presence of strong magnetic fields). When coronal mass ejections and solar flares appear, SDO and ATST will work in tandem to develop the connections between activity below the solar surface and the eruptions within the solar corona.
THE FREQUENCY AGILE SOLAR RADIO TELESCOPE (FASR)WILL PROBE THE MYSTERY OF SOLAR FLARES
The Frequency Agile Solar Radio telescope (FASR) will observe radio waves from the Sun, continually probing different heights above the solar surface. This range in altitude takes us from the Sun's corona with its million-degree temperature down through the chromosphere, heated to tens of thousands of degrees.Within the corona and chromosphere, FASR will observe short-lived, explosive phenomena-the flares that eject enormous amounts of hot gas, along with streams of elementary particles.