BOZEMAN â€“Montana State Universityâ€™s major role in a science satellite studying the sun was made clear in a recent issue of Science.
Five articles in a special section devoted to that satellite include MSU solar physicists Charles Kankelborg and Sarah Jaeggli as authors. Science is one of the worldâ€™s leading scientific journals and is published weekly by the American Association for the Advancement of Science. The cover of the Oct. 17 journal also carried two photos that came from solar instruments involving MSU research.
â€śIt is considered an achievement to publish an article in Science every so often. Publishing two in a year is great. Two in a single issue: wow,â€ť said MSU physics professor Dana Longcope. â€śBut Charles Kankelborg and Sarah Jaeggli have each managed to get five papers into a single issue of Science.â€ť
Nicol Rae, dean of the College of Letters and Science, said, â€śThis is simply outstanding.â€ť
According to NASA, the five papers highlight different aspects of the sunâ€™s energyâ€™s journey from the sunâ€™s surface through its atmosphere. By looking at various regions of the interface region in unprecedented resolution, the papers offer clues to what heats the corona to unexplained temperatures of millions of degrees, far hotter than the surface of the sun itself, as well as what causes great writhing movement and accelerated particles throughout the solar atmosphere.
Publishing five papers in one issue of Science is the most recent accomplishment of MSUâ€™s Solar Physics Group which is considered one of the best in the world. Kankelborg and Longcope each won the Presidential Early Career Award for Scientists and Engineers (PECASE), the highest award the U.S. government gives to science and engineering professionals who are in the early stages of their independent research careers. The group, as a whole, has garnered many national and international honors, as well. Kankelborg even has an asteroid named after him. Â Â Â
For their latest achievement, Kankelborg led an MSU team that designed, built, tested and calibrated the optics for the Interface Region Imaging Spectrograph (IRIS) satellite, which provided the data used in the five Science papers. Kankelborg added that the recently published papers were the first round of papers to come out of the NASA mission, and he expects many more.
Jaeggli said, â€śThis is a big accomplishment for the IRIS science team. There are many thanks that should be paid to our first authors, for working on this cutting-edge science and pushing it through to publication, and to IRIS lead scientist Bart De Pontieu for setting this goal for us in the first place.â€ť
Jaeggli came to MSU three years ago from the University of Hawaii in Honolulu where she earned her doctorate in the universityâ€™s Institute for Astronomy. She is now a postdoctoral research associate in MSUâ€™s Department of Physics.
Kankelborg â€“ who became a full professor of physics about the same time as this current round of Science papers was published â€“ was attending a 2007 solar physics conference in Honolulu when he was first approached by Lockheed Martin Corp. scientists and asked to collaborate on the IRIS mission.
Jaeggli now generates regular updates of the instrument calibration. Each week, a science planner generates daily command loads that control the observations. Jaeggli, Kankelborg and MSU graduate students are in the pool of people who take turns with this duty.
Any instrument that takes measurements needs to be calibrated, Kankelborg said. Because IRIS is orbiting 390 to 420 miles above Earth, it canâ€™t be taken to a shop for maintenance, so physicists calibrate it from their computers. That means they take into account a variety of factors about the satelliteâ€™s orbit and adjust their measurements accordingly. Factors can include such things as the angle that IRIS is orbiting, which can affect the temperature of its metal. The fluctuating temperature causes expansion and contraction which can affect the delicate instruments on board.
IRIS, which has now been orbiting the Earth for 16 months, was launched June 27, 2013 from the Vandenberg Air Force Base in California. It was designed to answer some of the biggest questions about the sun, such as why the corona is millions of degrees Celsius when a layer closer to the sun is much cooler, Kankelborg said. That layer, the photosphere, averages 6,000 degrees Celsius.
IRIS was the first mission designed to use an ultraviolet telescope to obtain high-resolution images every few seconds and provide observations of areas as small as 150 miles across the sun. IRIS carries an eight-inch ultraviolet telescope, a spectrograph that contains MSU optics, and a â€śbusâ€ť carrying transmitters and batteries. The telescope transmits ultraviolet light to the spectrograph. The spectrograph then splits invisible light into wavelengths like a prism splits visible light. The entire satellite is seven feet long, 12 feet wide and weighs 440 pounds.
Solar physicists use IRIS to see how solar material moves, gathers energy and heats up as it travels through the sunâ€™s lower atmosphere. The interface region between the sunâ€™s photosphere and corona drives the solar wind and powers its million-degree atmosphere. Its emissions affect the Earthâ€™s climate and can interfere with satellite communications and the transmission of power.
Evelyn Boswell, (406) 994-5135 or email@example.com