The Sun: just a star, like many others...
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A-The_Sun-SOHO-LASCO-2.gifA Day of the Sun (a GIF-Movie by Dr Gianluigi Barca - Lunexit Team)88 visitenessun commentoMareKromium
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A_-_The_Sun_-_Sunspots_-_Friedman.jpgFeatures of the Sun (picture taken in H-Alpha - False Colors)132 visiteTaken just last week (second week of November 2011), the Sun was captured sporting numerous interesting features including one of the larger Sunspot Groups yet recorded: AR 1339 visible on the image right. Only last year, the Sun was emerging from an unusually quiet Solar Minimum that lasted for years. The above image was recorded in a single color of light called Hydrogen Alpha, inverted, and false colored. Spicules cover much of the Sun's face. The gradual brightening towards the Sun's edges is caused by increased absorption of relatively cool solar gas and called limb darkening. Just over the Sun's edges, several scintillating Prominences protrude, while Prominences on the Sun's face are seen as light streaks. Possibly the most visually interesting of all are the magnetically tangled active regions containing cool Sunspots. As our Sun's Magnetic Field winds toward Solar Maximum over the next few years, increased activity will likely create times when the Sun's face is even more complex.MareKromium
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Active_Sun.jpgActive Sun (Credits: Mehmet Ergün)97 visiteCaption NASA Originale:"Our Sun is becoming a busy place. Only two years ago, the Sun was emerging from a solar minimum so quiet that months would go by without even a single sunspot. In contrast, already this year and well ahead of schedule, our Sun is unusually active, already nearing solar activity levels seen a decade ago during the last solar maximum. Our increasingly active Sun was captured two weeks ago sporting numerous interesting features. The image was recorded in a single color of light called Hydrogen Alpha, color-inverted, and false colored. Spicules carpet much of the Sun's face. The brightening towards the Sun's edges is caused by increased absorption of relatively cool solar gas and called limb darkening. Just outside the Sun's disk, several scintillating prominences protrude, while prominences on the Sun's face are known as filaments and show as light streaks. Magnetically tangled active regions are both dark and light and contain cool sunspots. As our Sun's magnetic field winds toward solar maximum over the next few years, whether the Sun's high activity will continue to increase is unknown".
“Non si presta mai attenzione a ciò che è stato fatto; si vede soltanto ciò che resta da fare"
Marie CurieMareKromium
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At the edge of the Sun.jpgAt the edge of the Sun64 visiteCaption NASA originale: "Dramatic prominences can sometimes be seen looming just beyond the edge of the Sun. A Solar Prominence is a cloud of solar gas held just above the surface by the Sun's magnetic field. The Earth would easily fit below the prominence on the left. 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 very hot, prominences typically appear dark when viewed against the Sun, since they are slightly cooler than the surface. The above image - in false color - was taken on June 1st, 2003, from Stuttgart, Germany, with a simple amateur telescope and camera".
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Athmosferic_Corona-Schneider.jpgDiamond Ring and Shadow Bands67 visiteDalla Rubrica "NASA - Picture of the Day" del giorno 24 Luglio 2010:"As the total phase of July ,11th, 2010 Solar Eclipse came to an end, Sunlight streaming past the edge of the Moon's silhouette created the fleeting appearance of a glistening Diamond Ring in the sky.
Seen through a thin cloud layer from the French Polynesian atoll of Hao it also produced remarkable Shadow Bands, flickering across the dramatic scene. Projected onto the cloud layer, the Shadow Bands are parallel to the sliver of Sunlight emerging from behind the Moon's edge.
Caused by turbulence in Earth's Atmosphere refracting the sliver of Sunlight, the narrow bands were captured in this brief, 1/400th second exposure. Shining through the cloud droplets, the Sunlight also produced a luminous atmospheric corona, not to be confused with the Solar Corona seen during Eclipse Totality.
The Atmospheric Corona is centered on the bright diamond of emerging Sunlight".MareKromium
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Black Sun.jpgBlack Sun73 visiteCaption NASA originale:"During a total solar eclipse, Earth's moon blocks the Sun - almost exactly. While the Sun is about 400 times wider than the Moon, it is also about 400 times farther away and each appears to be half a degree or so in diameter. On August 11, 1999 this remarkable coincidence in the apparent size of two vastly different celestial bodies produced tantalizing solar spectacles for denizens of Europe and Asia. For example, prominences along the Sun's limb peer around the Moon's dark edge in this dramatic picture of totality recorded as the lunar shadow swept across Hungary. Subtle structures in the Sun's inner corona are also visible streaming beyond the silhouetted Moon".
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BlueSun.jpgBlue Sun53 visiteDa "NASA - Picture of the Day" del giorno 4 Novembre 2009:"Our Sun may look like all soft and fluffy, but it is not. Our Sun is an extremely large ball of bubbling hot gas, mostly Hydrogen gas. The above picture of our Sun was taken last month in a specific red color of light emitted by Hydrogen gas called "Hydrogen-alpha" and then color inverted to appear blue.
In this light, details of the Sun's Chromosphere are particularly visible, highlighting numerous thin tubes of magnetically-confined hot gas known as spicules rising from the Sun like bristles from a shag carpet.
Our Sun glows because it is hot, but it is not on fire. Fire is the rapid acquisition of Oxygen, and there is very little Oxygen on the Sun. The energy source of our Sun is the nuclear fusion of Hydrogen into Helium deep within its core. No Sunspots or large active regions were visible on the Sun this day, although some Solar Prominences are visible around the edges".MareKromium
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Coronal Aurora - ISS.jpgCoronal Aurora from Space62 visiteOriginal caption:"From the ground, spectacular auroras seem to dance high above. But the International Space Station (ISS) orbits at nearly the same height as many auroras, sometimes passing over them, and sometimes right through them. Still, the auroral electron and proton streams pose no direct danger to the ISS. In 2003, ISS Science Officer Don Pettit captured the green aurora, pictured above in a digitally sharpened image. From orbit, Pettit reported that changing auroras appeared to crawl around like giant green amoebas. Over 300 Km below, the Manicouagan Impact Crater can be seen in northern Canada, planet Earth".
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Coronal Loops-TRACE.jpgCoronal loops66 visiteDa "NASA - Picture of the Day" del 14 Agosto 2005:"Why is the Corona of the Sun so hot? Extending above the photosphere or visible surface of the Sun, the faint, tenuous Solar Corona can't be easily seen from Earth, but it is measured to be hundreds of times hotter than the photosphere itself. Astronomers have long sought the source of the Corona's heat in magnetic fields which loft monstrous loops of solar plasma above the photosphere. Detailed observations of coronal loops from the orbiting TRACE satellite are pointing more closely to the unidentified energy source. Recorded in extreme ultraviolet light, this and other TRACE images indicate that significant heating occurs low in the corona, near the bases of the loops as they emerge from and return to the solar surface. This tantalizing TRACE image shows clusters of the majestic, hot coronal loops which span 30 or more times the diameter of planet Earth".
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Coronal Mass Ejection.jpgA "Coronal Mass Ejection"67 visiteCaption NASA originale:"Magnetic fields buckle releasing previously constrained hot material from the upper atmosphere of the Sun. As a result, hot gas streams out into the Solar System, impacting planets, moons, spacecraft, and making space a dangerous place for astronauts. Known as "Coronal Mass Ejections" (CMEs), billions of tons of scathing plasma can be accelerated to millions of miles per hour. CMEs are more common but less intense than solar flares".
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Earth&Sun-000-sunearth_01G.jpgMagnetic Fields... (1)53 visitenessun commento
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Earth&Sun-001-magfieldG_b.jpgMagnetic Fields... (2)53 visitenessun commento
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