1. MSU Solar Physics Group RHESSI and Max Millennium Reuven Ramaty High Energy Solar Spectroscopic Imager TRACE Transition Region And Coronal Explorer SSEL’s MOSES Space Science and Engineering Lab Yohkoh Magnetic Modeling The Group Researchers believe that energy released during a solar flare accelerates electrons, which emit primarily X-rays, and ions, which emit primarily gamma rays. NASA’s RHESSI mission, launched in Feb. 2002, combines for the first time high-resolution imaging in hard X-rays and gamma rays with high- resolution spectroscopy, providing detailed energy spectra at each point of a solar flare image. Co-investigator: Prof. Richard Canfield (MSU) MSU oversees the Max Millennium Program to coordinate observations, data analysis, and theory of solar flares. The MSU solar group plays a large role in the day-to-day operation and scientific utilization of the NASA TRACE mission which was launched early in 1998. This battery of 4 ultraviolet telescopes provides spectacular new observations of the thin and dynamic interface region at the base of the corona. This region is also the source of much of the ionizing radiation that determines the properties of the upper atmosphere of the earth, such as the ionosphere and the ozone layer. MSU’s laboratory for the construction of space experiments on rockets and satellites. Director: Prof. David Klumpar The project closest to our hearts is a rocket payload called the Multi-Order Solar EUV Spectrograph. MOSES, under the leadership of Prof. Charles Kankelborg, gets an unbelievable wealth of full-Sun EUV imaging and spectroscopy information, just waiting to be picked apart by a curious physicist. MSU’s Solar Theory Group, Prof. Dana Longcope, Prof. Piet Martens, performs analytic and computational studies of solar magnetic fields, addressing questions like:  How does the coronal magnetic field become stressed & why does it suddenly release its stress as a flare or microflare? (Perhaps discontinuities, like "fractures", form in the magnetic field.)  What identifies the part of the magnetic field where stress will accumulate? (Where will it "fracture"?)  How does the magnetic field generated inside the Sun rise to the surface? It seems to form slender strands (flux tubes)—why?  Can details of the rise process tell us anything about the way magnetic field is generated inside? The primary emission of the extremely hot outer atmosphere of the Sun, the solar corona, is at X-ray wavelengths. The extended duration, high resolution X-ray images from Yohkoh are being analyzed in an effort to learn why the Sun has a corona and why it varies in intensity so strongly in response to the 11-year solar cycle. This satellite carried a solar X-ray telescope, prepared under the leadership of Prof. Loren Acton (MSU), designed to study high energy processes on the Sun. MSU is actively analyzing the results from the Japan/US/UK Yohkoh mission for studies of high-energy solar physics, which was launched in 1991 and operated until December 2001. SDO/AIA Webpage: solar.physics.montana.edu MSU Solar Physics is… The Solar Dynamics Observatory will be the flagship for NASA's Living With a Star program, providing continuous observations of the Sun's magnetic fields, its surface and atmosphere, and the overall radiative output. MSU is a partner with Lockheed Martin Solar and Astrophysics Laboratory and the Harvard Smithsonian Astrophysical Observatory in the development of SDO's Atmospheric Imaging Assembly, which will be the most complex extreme-ultraviolet telescope ever constructed. Co-investigators: Prof. Piet Martens, Prof. David McKenzie (both MSU). With a full-Sun field of view and unsurpassed clarity, AIA will observe in eight wavelength passbands to sample eight distinct regimes of plasma temperature every ten seconds, yielding the most complete picture of solar activity to date.