Weird Aurora-Like Emissions Right Above Sunspot Seen 7 Years Ago Lasted for a Week

NASA noticed weird emissions resembling auroras seven years ago, directly over a sunspot. The colorful emissions persisted for approximately a week.

Weird Aurora-Like Emissions Right Above a Sunspot

A group of astronomers examined radio emissions originating approximately 24,855 miles above a Sun's dark region, noting aurora-like characteristics. These emissions appeared above a sunspot, areas on the Sun with significantly stronger magnetic fields compared to Earth's, causing cooler temperatures.

Detected in April 2016 by the Jansky Very Large Array, the research team recently disclosed their analysis, highlighting the emissions' aurora-like nature based on various factors like spectra and polarization.

Sijie Yu, lead author and astronomer at the New Jersey Institute of Technology's Center for Solar-Terrestrial Research (NJIT-CSTR), described these emissions as unusual long-lasting polarized radio bursts emerging from a sunspot, persisting for over a week. Yu expressed excitement about this discovery, which deviates from typical transient solar radio bursts lasting minutes or hours. This finding holds the potential to reshape the general understanding of stellar magnetic processes, as stated in an institute release.

Sunspot Radio Aurora

Auroras, generated when solar particles interact with Earth's magnetic field and atmosphere, manifest as vibrant glows due to atmospheric gases. NASA notes oxygen creates red and green auroras, while nitrogen produces blue and purple hues. Contrasting Earth's auroras, sunspot aurora emissions, detailed by Yu, occur at frequencies between hundreds of thousands to roughly 1 million kHz, a consequence of sunspots possessing magnetic fields thousands of times stronger than Earth's.

Earth's auroras are distinctive, yet recent observations have unveiled auroral displays on other planets. The Webb Space Telescope captured bright blue auroral regions on Jupiter's poles using NIRCam, while the Keck II Telescope's NIRSPEC detected infrared auroras on Uranus's edges, supplementing known ultraviolet auroras above the planet.

Researchers suggest the sunspot radio emissions might not align with solar flare timings. Instead, they propose that intermittent flares inject electrons into magnetic field loops linked to sunspots. This insight hints at the potential existence of "sunspot radio auroras" in other stars, expanding our comprehension of stellar phenomena.

Implications of a Sunspot Aurora

Physicist Dale Gary, from NJIT-CSTR and a co-author of the study, highlighted the importance of comprehending solar signals for interpreting emissions from M-dwarfs, the most prevalent star type in the universe.

These insights could unveil fundamental connections in astrophysical phenomena. While ground-based observations like those conducted by the Very Large Array aid understanding, spacecraft like NASA's Solar Orbiter and Parker Solar Probe offer deeper insights into solar dynamics. The Solar Orbiter traverses coronal mass ejections, unraveling storm characteristics, while the Parker Solar Probe delves into the Sun's corona.

Despite powering Earth for eons, the Sun retains mysteries. Advancing our comprehension of this local star is crucial given its role in supporting life. The team's discoveries shed light on the origins of intense solar radio bursts, potentially offering explanations for aurora-like radio emissions in other flare stars with sizable starspots. This progress marks a significant step toward unraveling celestial enigmas.