Solar sensation

Neither brutal cold nor the threat of curious polar bears dissuaded University of Hawaii astronomer Shadia Habbal and her intrepid band of Solar Wind Sherpas from observing the March 20 total solar eclipse from the incomparable but inhospitable vantage point of a remote island off the northern coast of Greenland.

Preliminary results from the team’s observations were presented April 30 at the Triennial Earth-Sun Summit in Indianapolis.

The team observed the eclipse from two locations — the old Northern Light Observatory and an airport hangar 10 miles away — in Longyearbyen, on the island of Spitsbergen in the Svalbard archipelago.

According to a University of Hawaii news release, both locations were equipped with identical instruments, which included six digital single-lens reflex cameras fitted with different focal length lenses, and four astrophotography cameras with special filters to observe colors of light given off by ionized iron atoms, which probe the high-temperature outer layers of the sun.

The observatory was further outfitted with a dual-channel spectrograph (designed by Adalbert Ding of the Technische Universitat and Institute of Technical Physics in Berlin), which was used to measure the motions of ions in the sun’s corona. At the airport hangar, UH astronomer Haosheng Lin used a spectropolarimeter that he designed and constructed to measure the sun’s magnetic fields.

The team captured images of the corona at an altitude of 12 degrees throughout the 2 minutes and 20 seconds that it was totally obscured by the moon. The team also took advantage of the snow-covered landscape to observe thin bands of light and dark — called shadow bands — prior to and during totality.

In addition to the two groups operating in Longyearbyen, additional Solar Wind Sherpas teams were dispatched to the Faroe Islands, between Iceland and Norway — a Dassault Falcon aircraft flying at 49,000 feet over the Faroe Islands and an Irish Air Corps CASA CN-235 aircraft flying out of Dublin.

The Solar Wind Sherpas team included Habbal, Lin and Garry Nitta of the UH Institute for Astronomy; Ding; Judd Johnson of Electricon in Boulder, Colo.; Miloslav Druckmueller, Pavel Starha, Jana Hoderova and Jan Malec of Brno University of Technology and Petr Starha of Brno in the Czech Republic; Peter Aniol of Astelco Corp. and Martin Dietzel of Zeiss Corp. in Germany; Feras Habbal of the University of Texas at Austin; Yaseen Almleaky of King Abdullah University in Saudi Arabia; Huw Morgan, Duraid Al-Shakarshi, Nathalia Alzate and Joe Hutton of Aberystwyth University in Wales; Martina Arndt of Bridgewater State University in Massachusetts; and Scott Gregoire of Granite Mountain Research in Boulder, Colo.

The expedition was financed through National Science Foundation and NASA grants awarded to the University of Hawaii, with additional support from King Abdullah University and Astelco Corp.