Sun corona facts5/7/2023 ![]() ![]() Astronomers have named them "helmet streamers" because of their resemblance to spiked helmets worn by knights (and also to those used by some German soldiers up to 1918). From the tops of such "arches" long streamers may extend, to distances of the Sun's diameter or even more, looking like pulled taffy, as if some process was pulling material away from the tops of the arches into space, (which is of course what the solar wind actually does). Structures observed in the corona above sunspots often have horseshoe-shaped outlines, again suggesting that they follow magnetic field lines. For instance, short "plumes" rising from the polar regions of the Sun look very much like field lines coming out of the end of a bar magnet, and they therefore suggest that the Sun, in addition to the intense fields of sunspots, also has a global magnetic field like the Earth's. Structures visible in the corona at such times suggest that they are shaped by magnetic fields, and therefore, that the corona consists of plasma. This is the only time that the corona, the ring of hot plasma surrounding the Sun, becomes visible, as in this image from the European Southern Observatory of the last total eclipse of the Sun visible in Germany on 11 August 1999.During a total eclipse of the Sun, when for a few minutes the Moon completely covers the Sun's face, a glow appears around the darkened Sun-the solar corona, the Sun's outermost atmosphere. Stars are visible in the middle of the day and the environment changes – the animal world becomes restless. When the new moon crosses the Sun’s disk and the tip of the shadow cone races across the surface of the Earth, it becomes dark for a few minutes in places over which the umbra passes. No other astronomical event makes humans more aware of the ‘cosmic clockwork’ of our Solar System than a solar eclipse. ![]() This is the only time that the corona, the ring of hot plasma surrounding the Sun, becomes visible, as in this image from the European Southern Observatory of the last total eclipse of the Sun visible in Germany on 11 August 1999.Īustrian writer Adalbert Stifter wrote a very poetic description of the celestial phenomenon about the solar eclipse of 8 June 1842, which he observed in Vienna: “The Moon stood in the centre of the Sun, no longer a black disk, but semi-transparent, as if surrounded by the lustre of steel, with no edge of the Sun around it, but a wonderful, beautiful, glowing circle of blue, red, bursting out in rays, no differently than if the Sun above were pouring its flow of light onto the sphere of the Moon below so that it spattered around – the loveliest thing I have ever seen light do!” Stars are visible in the middle of the day and the environment changes – the animal world becomes restless. When the new moon crosses the Sun’s disk and the tip of the shadow cone races across the surface of the Earth, it becomes dark for a few minutes in places over which the umbra passes. No other astronomical event makes humans more aware of the ‘cosmic clockwork’ of our Solar System than a solar eclipse. The magical moment of totality – the Sun’s corona is visible ![]()
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