On Feb. 1, 2011, the Hinode satellite captured this breathtaking image of a coronal hole, the dark area seen at the right side of this image. A second, polar coronal hole can also be seen at left.
Notice also the north polar-crown filament, the trans-equatorial loops, and the coronal hole in the south-east (lower-right) corner of the image and the smaller one over the north pole .
One other interesting aspect of the relation of coronal holes to the solar wind follows from the appearance of coronal holes at the poles.
Some statistical relationships between coronal holes and prominence in solar active cycle 21 are analysed.
Japan's Hinode sun-watching satellite photographed the sun's two coronal holes on Feb. 1.
In this paper the author expound mainly the current status in the research of solar quiet corona, coronal holes and heating mechanism of corona.
