https://www.esa.int/ESA_Multimedia/Images/2023/10/Small-scale_magnetism_leads_to_large-scale_solar_atmosphere

ESA menu toggle ESA search toggle ESA title
ESA logo
[                    ]
Image comparing views of Sun with two Solar Orbiter instruments
[Small-scal]
Science & Exploration

Small-scale magnetism leads to large-scale solar atmosphere

05/10/2023 6901 views 121 likes 482996 ID
Like
Download

  * HI-RES PNG - IMAGE 1 [1.51 MB]
  * HI-RES PNG - IMAGE 2 [2.63 MB]

Thank you for liking

You have already liked this page, you can only like it once!

 
Details Related

Thanks to close-up images of the Sun obtained during Solar Orbiter's
perihelion passage of October 2022, solar physicists have seen how
fleeting magnetic fields at the solar surface build up into the solar
atmosphere.

The outer solar atmosphere is known as the solar corona. It is termed
'quiet' when there is little appreciable solar activity such as
flares or coronal mass ejections. How the quiet corona reaches a
temperature of a million degC when the surface is just at ~6000 degC is a
long-running mystery.

Although the action of magnetic fields has long been suspected, the
nature of the magnetic processes responsible has never been fully
understood. These new images of the quiet Sun show how loops of
million-degree gas - which form the building blocks of the solar
corona - are associated with fleeting 100-km-sized magnetic field
patches on the solar surface.

The images show the view from two of Solar Orbiter's instruments. The
yellow image was taken by the Extreme Ultraviolet Imager (EUI) and
shows clearly the arch-like hot loops of plasma that reach up into
the solar corona. The speckled image comes from the Polarimetric and
Helioseismic Imager (PHI), and reveals the magnetic polarity of the
solar surface. The red and blue shaded regions represent patches of
north and south magnetic polarities. A clear correlation can be seen
between the small patches of magnetic fields and the coronal loops.

The coronal loops are apparently linked to scattered concentrations
of the small-scale magnetic field concentrations on the surface,
often with mixed-polarity configuration. This complex arrangement and
the temporal evolution of these small magnetic field patches play a
role in the building of the million-degree corona.

These observations capture surface magnetic structures and coronal
features at almost the same high spatial resolution of ~200 km,
allowing the data from the two instruments to be closely compared.
With these unique data, solar physicists now have a window to
investigate the role of the small-scale magnetic fields in the
building of solar corona.

Like the perihelion pass that gave these results, Solar Orbiter is
currently preparing for another close pass of the Sun on 7 October
2023. On that day, the spacecraft will get as close as 43 million km
to the Sun - i.e., closer to the Sun than the innermost planet
Mercury. This allows Solar Orbiter to view the Sun in precise detail,
revealing the previously unseen small-scale processes that appear to
drive so much of the Sun's hot atmosphere.

 

Solar Orbiter is a space mission of international collaboration
between ESA and NASA, operated by ESA. This new result is reported in
the paper 'Fleeting small-scale surface magnetic fields build the
quiet-Sun corona' by L. P. Chitta et al, published in Astrophysical
Journal Letters 5 October 2023.

  * 
    ESA & NASA/Solar Orbiter, Left: EUI team, Right: PHI team
  * 
    Space Science
  * 
    Solar Orbiter
  * 
    Solar corona Sun corona Atmosphere (corona) Sun magnetic field

Solar 'magnetic carpet' Science & Exploration

Solar 'magnetic carpet'

Image 1420 views 1 likes
[Tiny_magne] Science & Exploration

Tiny magnetic episodes may have large consequences o...

Video 00:00:42 8317 views 138 likes
Solar Orbiter's space hedgehog Science & Exploration

Solar Orbiter's space hedgehog

Image 12764 views 71 likes
Searching for solar jets Science & Exploration

Searching for solar jets

Image 2302 views 43 likes
Composite view of the Sun's corona Science & Exploration

Composite view of the Sun's corona

Image 796 views 14 likes