| Piú viste - The Sun: just a star, like many others... |
Solar_Prominence.jpgSolar Prominence78 visiteCaption NASA, da "NASA - Picture of the Day" del giorno 15 Marzo 2009:"What's happened to our Sun? It was sporting a spectacular -- but not very unusual -- Solar Prominence.
A Solar Prominence is a cloud of solar gas held above the Sun's Surface by the Sun's Magnetic Field. In 2004, NASA's Sun-orbiting SOHO Spacecraft imaged an impressively large prominence hovering over the surface, pictured above.
The Earth would easily fit under the hovering curtain of hot gas.
A quiescent Prominence typically lasts about a month, and may erupt in a Coronal Mass Ejection (CME) expelling hot gas into the Solar System. Although somehow related to the Sun's changing Magnetic Field, the energy mechanism that creates and sustains a Solar Prominence is still a topic of research".MareKromium
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Sunspots-090602.jpgSunspots and Clouds in Solar Cycle 2478 visiteDa "NASA - Picture of the Day" del giorno 4 Giugno 2009:"On June 2nd, 2009, clouds over Stuttgart, Germany parted to reveal what has become a relatively rare sight, spots on the Sun. In fact, the roughly 11-year solar activity cycle is still in a surprisingly deep minimum and the years 2008 and 2009 have had the lowest Sunspot counts since the 1950s. Even the latest prediction is that the new cycle, Solar Cycle 24, will reach a maximum in May 2013 with a below-average sunspot count. The Solar Cycle 24 Sunspots recorded here are in active region AR 1019.
Previously, only two cycle 24 active regions with Sunspots, AR 1018 and AR 1017, were seen in May".MareKromium
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The Sun-EIT99promcloseG.jpgOur "restless" Sun...and Us!77 visitenessun commento
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Sun & Comet.jpgA comet approaching the Sun (from SOHO)76 visiteCaption NASA originale:"These 3 frames from SOHO's coronograph were taken two hours apart from each other on April 29, 2000. They show a "sungrazer" (SOHO comet discovery number 111) with a long, bright tail headed toward its fiery encounter.
The Sun itself is hidden behind the coronograph's occulting disk at each frame's upper right".
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Sun & Comet (2).jpgA comet approaching the Sun (from SOHO)76 visiteCaption NASA originale:"SOHO, the space-based SOlar and Heliospheric Observatory, has become by far the reigning champion facility for discovering comets, its total having reached more than 200. As might be expected of a solar observatory, most of the SOHO discovered comets are "sungrazers", such as comets destined to dive within a mere 50.000 Km or so of the solar photosphere.
At that range the intense heat and gravitational forces make it unlikely these primitive chunks of ice and dust will survive".
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ZZ-ZZ-HybridEclypse-Heinsius_Panama_tse2005_1.jpgAn unusual "Hybrid Solar Eclipse" (2)76 visiteDa "NASA - Picture of the Day" del 6 Maggio 2005:"(...) But for Stephan Heinsius, near the end of the shadow track at Penonome Airfield, Panama, the Moon's apparent size had shrunk enough to create an anular eclipse, showing a complete anulus of the Sun's bright disk as a dramatic "Ring of Fire".
(...) How rare is such a Hybrid Eclipse?
Calculations show that during the 21st century just 3,1% (7 out of 224) of Solar Eclipses are hybrid while hybrids comprise about 5% of all Solar Eclipses over the period from 2.000 BC to AD 4.000".
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The Sun-20031202_c2_EIT304.jpgOur "restless" Sun... (1)76 visitenessun commento
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The Sun-C2_EIT_Nov8_00G.jpgOur "restless" Sun... (2)76 visitenessun commento
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The Sun-UvcseitG_c.jpgOur "restless" Sun... (12)76 visitenessun commento
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The_Sun_and_Mercury.jpgThe Sun and Mercury76 visiteEnjoying the transit of Mercury from Dallas, Texas, astronomer Phil Jones recorded this detailed image of the Sun. Along with a silhouette of the innermost Planet, a network of cells and dark filaments can be seen against a bright solar disk with spicules and prominences along the Sun's edge. The composited image was taken through a telescope equiped with an H-alpha filter that narrowly transmits only the red light from Hydrogen atoms. Such images emphasize the Solar Chromosphere, the region of the Sun's atmosphere immediately above its Photosphere or normally visible surface. Left of center, the tiny disk of Mercury seems to be imitating a small sunspot that looks a little too round. But in H-alpha pictures, sunspot regions are usually dominated by bright splotches (called plages) on the Solar Chromosphere.
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Sun_Shock-Wave.gifThe "Moreton Wave"76 visiteCaption NASA originale:"Tsunamis this large don't happen on Earth. One week ago (Dec. 2006), a large solar flare from an Earth-sized sunspot produced a tsunami-type shock wave that was spectacular even for the Sun. Pictured above, the tsunami wave was captured moving out from active region AR 10930 by the Optical Solar Patrol Network (OSPAN) telescope in New Mexico, USA. The resulting shock wave, known technically as a Moreton Wave, compressed and heated up gasses including Hydrogen in the photosphere of the Sun, causing a momentarily brighter glow.
The above image was taken in a very specific red color emitted exclusively by hydrogen gas. The rampaging tsunami took out some active filaments on the Sun, although many re-established themselves later.
The solar tsunami spread at nearly 1 MKM per hour, and circled the entire Sun in a matter of minutes".MareKromium
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The_Sun_-_Eclipse.jpgAt the Sun's Edge76 visiteCaption NASA:"A train trip on the Trans-Siberian railway to Novosibirsk resulted in this stunning view along the edge of the Sun, recorded during the August 1st, 2008, total Solar Eclipse.
The picture is a composite of two images taken at special moments in the eclipse sequence, corresponding to the very beginning and the very end of the total eclipse phase.
Those times are known to eclipse chasers as 2nd and 3rd contact.
Bright beads around the Moon's dark silhouette are rays of sunlight shining through lunar valleys at the edge of the Lunar Disk.
But the composite view also captures Solar Prominences, such as "looping structures" of hot plasma suspended in magnetic fields, extending beyond the Sun's edge".MareKromium
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