Although experimental validation is at the heart of the scientific method, there is a wide range of difficulty when it comes to setting up such an experiment. Testing what underlies the formation of the fast solar wind from coronal holes in the sun’s corona is one such challenging experimental setup. However it seems we are now We have our answerwith Recently published paper in nature By SD Bale and colleagues detailing what we learned with permission from Parker Solar Probe (PSP), which has been on its way to the Sun since its August 2018 launch from Earth.
the sun solar wind It is the name for a stream of charged particles that emanate from the sun’s corona, and two types are generally distinguished: the slow and fast solar wind. The first type seems to have originated from the Sun’s equatorial belt and is gently moving away from the Sun at only 300-500 km/s with a moderate temperature of 100 MW. The fast solar wind comes from Coronal holes, which are temporary regions of cooler, less dense plasma within the corona. These coronal holes are characterized by being regions in which the sun’s magnetic field extends into interplanetary space as an open field, where charged particles from the corona can escape the sun’s gravitational field.
The properties of coronal holes allow the resulting stream to travel at speeds of about 750 km/s and with blisters of 800 MK. What wasn’t clear up until this point was exactly what the forces were to accelerate the plasma. The source was supposed to be wave heating, as well as exchange reconnection, but with the PSP now close enough to make the relevant measurements, the evidence points to the latter.
Basically, cross-reconnection is the re-establishment of coronal hole field lines after interaction with convective cells on the Sun’s photosphere. These convection cells pull the magnetic field into a kind of funnel, after which the field lines re-establish themselves, expelling hotter plasma from the slow solar wind. Thanks to the PSP’s measurements, the measured fast solar winds can be matched with coronal holes, along with magnetic fields. This gives us the clearest picture yet of how this phenomenon works, and how we can predict it.
(Banner photo: A diagram of the Sun. (Credit: Kelvinsong))
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