Airborne InfraRed Spectrograph (AIR-Spec) 2019 Eclipse Flight

Smithsonian Institution Astrophysical Observatory, Cambridge MA

Investigators

Abstract

The 2017 eclipse observations by the Airborne InfraRed Spectrometer (AIR-Spec) demonstrated that thermal infrared (IR) imaging spectroscopy is possible from the NCAR's HIAPER GV platform. This opened a new window of opportunity for high resolutions thermal IR spectroscopy of the Sun's corona on a platform that avoids the vast majority of the atmospheric absorption. The 2017 AIR-Spec eclipse observations revealed all of the target coronal emission lines at several coronal positions, showed Hydrogen lines in the prominence observations and captured the chromospheric flash spectrum. This three-year project is intended to re-fly the AIR-Spec instrument during the 2019 July 2 total solar eclipse in the south Pacific off the coast of Chile. During this project, the AIR-Spec will be upgraded to have an improved sensitivity, image stability, and automation of the data collection process. The goal is to characterize the thermal IR emission of Sun's corona, including an investigation of numerous coronal IR emission lines, across a variety of solar structures (coronal holes, plumes, prominences, etc.) on an otherwise almost unexplored physical regime. The project's primary personnel are two very early-career women (one scientist, one engineer), and additional REU students will be involved -- including for the flight preparations themselves. The project team is committed to fostering diversity and inclusion while training the next generation of instrumentation scientists and engineers in the U.S. The first AIR-Spec flight succeeded in measuring all targeted five infrared (IR) coronal emission lines, including the first-of-its-kind measurement of the coronal Fe IX line at 2.845 microns. The re-flight of AIR-Spec during the 2019 solar eclipse will allow the project team to focus on the detailed characterization of various emission lines in different conditions of the Sun's corona. The upcoming AIR-Spec experiment will exercise a different capability of the NCAR's GV aircraft. Namely, the IR transmissive window will be mounted on a side portal adjacent to the optical bench. In doing so, the project team will demonstrate the flexibility of the design, simplify the operations and verify their ability to observe eclipses anywhere in the world. Developing the ability for coordinated observations of the Sun's corona with the future DKIST will be greatly beneficial for the calibration of DKIST observations, and it will motivate future solar instrumentation. The research and EPO agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.