David M Rust

United States

1939-2019

Obituary:

http://spd.stanford.edu//SolarNews/current.html#section_antiochos

Passing of David Rust
Spiro Antiochos
14 Feb 2019
Dear Colleagues,

With great sorrow, I report the passing of our colleague and close friend David M. Rust on February 12, 2019. Dave was one of the pioneers of solar astronomy. For his PhD thesis at the High Altitude Observatory (HAO), Dave built the telescope and made the first accurate measurements of the magnetic field in quiescent prominences. Dave’s measurements at HAO and the Sacramento Peak Observatory (where he worked after his PhD) determined many of the prominence magnetic properties now in textbooks. He showed that the horizontal field increased with height, that the prominence magnetic shear cannot be due directly to differential rotation, and more recently, he contributed extensively to understanding the chirality rules for prominences and to measuring twist as a predictor of eruption. Dave’s work is the genesis for much of the large body of research, at present, on prominence measurement and modeling.

With the launch of Skylab, Dave turned his attention to the revolutionary new data coming from space missions. He joined American Science and Engineering (AS&E) in Boston, MA in 1974 to analyze X-ray images from S-054, the X-ray telescope that laid the foundation for modern solar physics. Dave was one of the first to use measurements of photospheric magnetic flux along with field line extrapolation and comparison with X-ray flare loops, in order to infer the nonpotentiality of the coronal field. He established the key result that magnetic shear is concentrated in low-lying field near the photospheric neutral line, whereas high-lying field is nearly potential. This property of the coronal field is fundamental to essentially every present-day theory for flares and CMEs. In further work, Dave elucidated many other basic properties of flares, such as their association with flux emergence. His 1977 paper with Haeyverts and Priest on the flux emergence model is still one of the most widely quoted papers in our field.

After leaving AS&E, Dave continued working on space data from the Solar Maximum Mission and Yohkoh, and along with De Jager and Švestka initiated the highly successful international Solar Maximum Year in 1979, one of the first large campaign programs in solar physics. He subsequently joined the Johns Hopkins University Applied Physics Lab (APL) in Maryland in 1983 where he founded the Center for Applied Solar Physics. At APL Dave continued his pioneering work with seminal contributions in both theory/observation and experiment. He was one of the first to emphasize the importance of helicity for interpreting the structure and dynamics of the solar field. Dave’s work on the comparison between remote sensing estimations of magnetic helicity in the corona with in-situ measurements in the solar wind at 1AU was a landmark result. It spawned a major industry in relating solar wind data to solar observations. Dave’s experimental work also had profound impact on the field. Working on a shoestring budget, Dave undertook the development of a meter-class balloon-borne telescope, the Flare Genesis Project, which delivered unique data on the early magnetic evolution of active regions, and inspired major international programs for further balloon-borne vector magnetographs. Dave said that his trips to McMurdo Station, Antarctica, for launching Flare Genesis were among the high points of his life.

In addition to being a dedicated solar physicist, Dave was an avid outdoorsman and art lover. He was an expert on modern art and had an extensive collection of original and exquisite pieces. He was an ardent sailor, owning several boats during his life, and he loved hiking the Rockies near Denver where he was born and spent his early years. But Dave’s foremost passion was science. He had enormous enthusiasm and drive for understanding the Sun. Some of my most enjoyable and most instructive experiences were discussing and debating solar physics with Dave. He will be greatly missed.