Search Publications

In situ observations of large-amplitude Alfvén waves heating and accelerating the solar wind

Stawarz, Julia E.; Kasper, Justin C.; Louarn, Philippe +16 more

After leaving the Sun’s corona, the solar wind continues to accelerate and cools, but more slowly than expected for a freely expanding adiabatic gas. Alfvén waves are perturbations of the interplanetary magnetic field that transport energy. We use in situ measurements from the Parker Solar Probe and Solar Orbiter spacecraft to investigate a stream…

Picoflare jets power the solar wind emerging from a coronal hole on the Sun

Barczynski, K.; Peter, H.; Chitta, L. P. +17 more

Coronal holes are areas on the Sun with open magnetic field lines. They are a source region of the solar wind, but how the wind emerges from coronal holes is not known. We observed a coronal hole using the Extreme Ultraviolet Imager on the Solar Orbiter spacecraft. We identified jets on scales of a few hundred kilometers, which last 20 to 100 seco…

Thin jets underlie the solar wind

Ugarte-Urra, Ignacio; Wang, Yi-Ming

The Solar Orbiter spacecraft was launched in 2020 by the European Space Agency to study how solar activity drives changes in the inner part of the heliosphere, the region that extends from the Sun to the surrounding interstellar medium. The Solar Orbiter is fitted with a suite of in situ and remote-sensing instruments that allow measurement of the…

‘Campfires’ may drive heating of solar atmosphere

Clery, Daniel

Researchers are getting closer to solving the mystery of why the Sun's wispy atmosphere is nearly 200 times hotter than its surface. Temperatures ought to decline as one moves out from the Sun's core, but the solar atmosphere, or corona, seethes at more than 1 million degrees Celsius, far hotter than the 5500°C temperature of the surface. Flares h…