NJIT researchers will follow in the moon’s slipstream to capture high-res sunspot images
While much of the research around the eclipse on Monday will focus on the effects of the Sun's brief, daytime disappearance on Earth and its atmosphere, a group of solar physicists will be leveraging the rare event to capture a better glimpse of the star itself.
NJIT physicists Dale Gary and Bin Chen and collaborators will be observing sunspots — the visible concentrations of magnetic fields on the Sun's surface- – at microwave radio wavelengths from NJIT's Expanded Owens Valley Solar Array (EOVSA) near Big Pine, Calif. and from the Jansky Very Large Array (VLA) radio telescope near Socorro, N.M, which is operated by the National Radio Astronomy Observatory. While neither site is in the path of totality, they will both have between 75 to 80 percent coverage.
"Radio waves from the solar corona have long wavelengths, and as resolution is proportional to wavelength, our images ordinarily have rather low spatial resolution. But we can capture sharper images as we move in the direction of the Moon's motion as it blocks different parts of the Sun at different times," explains Gary, a distinguished professor of physics at NJIT's Center for Solar-Terrestrial Research (CSTR), adding, "Radio waves are sensitive to the otherwise invisible corona of the Sun, especially its magnetic field, so we will use the eclipse to make high-resolution images of the corona above active regions."
Sunspots are the primary generator of solar flares, the sudden, powerful blasts of electromagnetic radiation and charged particles that burst into space during explosions on the Sun's surface. Their turning motion causes energy to build up that is released in the form of flares.
Gary says there is nothing inherently different about the coming eclipse as compared to previous events, but he notes that researchers who use radio telescopes will be able to observe it much more clearly this time.
"What is different is that both EOVSA and the VLA have much greater capabilities than in the past," he says, "so we expect much better radio images and more complete frequency coverage from which to deduce the magnetic field, temperature and density of the corona."
NJIT recently expanded the Owens Valley array, adding eight new antennas to the existing seven, and replacing the control systems and signal processing. The solar science to be addressed focuses on the magnetic structure of the solar corona, on transient phenomena resulting from magnetic interactions, including the sudden release of energy and subsequent particle acceleration and heating, and on space weather phenomena.
Gary and Chen, an assistant professor of physics at CSTR, are working with researchers Timothy Bastian and Tony Beasley at the National Radio Astronomy Observatory, Jay Pasachoff at Williams College and Stephen White at the Air Force Research Laboratory.
One of the nation's leading public technological universities, New Jersey Institute of Technology (NJIT) is a top-tier research university that prepares students to become leaders in the technology-dependent economy of the 21st century. NJIT's multidisciplinary curriculum and computing-intensive approach to education provide technological proficiency, business acumen and leadership skills. With an enrollment of 11,400 graduate and undergraduate students, NJIT offers small-campus intimacy with the resources of a major public research university. NJIT is a global leader in such fields as solar research, nanotechnology, resilient design, tissue engineering, and cybersecurity, in addition to others. NJIT is among the top U.S. polytechnic public universities in research expenditures, exceeding $130 million, and is among the top 1 percent of public colleges and universities in return on educational investment, according to PayScale.com. NJIT has a $1.74 billion annual economic impact on the State of New Jersey.