Editing Stellar corona (section)

===Coronal holes===
{{main|Coronal hole}}
Coronal holes are unipolar regions which look dark in the X-rays since they do not emit much radiation.<ref>{{cite journal|doi = 10.1088/0004-637X/719/1/131|last1 = Ito |first1 = Hiroaki|last2 = Tsuneta|first2 = Saku|last3 = Shiota|first3 = Daikou|last4 = Tokumaru|first4 = Munetoshi|last5 = Fujiki|first5 = Ken'Ichi | title = Is the Polar Region Different from the Quiet Region of the Sun?| journal = The Astrophysical Journal | volume = 719 |issue = 1 | pages = 131–142| year = 2010 | bibcode=2010ApJ...719..131I|arxiv = 1005.3667 |s2cid = 118504417 }}</ref> These are wide zones of the Sun where the magnetic field is unipolar and opens towards the interplanetary space. The high speed solar wind arises mainly from these regions.

In the UV images of the coronal holes, some small structures, similar to elongated bubbles, are often seen as they were suspended in the solar wind. These are the coronal plumes. More precisely, they are long thin streamers that project outward from the Sun's north and south poles.<ref>{{cite journal| doi=10.1051/0004-6361:20021628| last1=Del Zanna | first1=G.| last2=Bromage| first2=B. J. I.| last3=Mason| first3=H. E.| title= Spectroscopic characteristics of polar plumes| journal= Astronomy & Astrophysics| year=2003| volume=398| issue=2 | pages= 743–761| bibcode=2003A&A...398..743D| doi-access=free}}</ref>