The Sun: just a star, like many others...
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Solar_Corona-TSE2010_JLD4.jpgThe "Crown" of the Sun65 visiteDalla Rubrica "NASA - Picture of the Day" del giorno 21 Luglio 2010:"During a total Solar Eclipse, the Sun's extensive Outer Atmosphere, or Corona, is an inspirational sight. Subtle shades and shimmering features that engage the eye span a brightness range of over 10,000 to 1, making them notoriously difficult to capture in a single photograph.
But this composite of 7 consecutive digital images over a range of exposure times comes close to revealing the Crown of the Sun in all its glory. The telescopic views were recorded from the Isla de Pascua (Easter Island) during July, 11th, 2010 Total Solar Eclipse and also show solar prominences extending just beyond the edge of the eclipsed Sun.
Remarkably, features on the dim, Near Side of the New Moon can also be made out, illuminated by Sunlight reflected from a Full Earth".MareKromium
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Solar_Corona.jpgIt's a "Corona", but it is not a "Beer", it's a "Crown", but is not a "Cola"...53 visiteDa "NASA - Picture of the Day", del giorno 8 Agosto 2008:"During a Total Solar Eclipse, the Sun's extensive Outer Atmosphere, or Corona, is an inspirational sight. The subtle shades and shimmering features of the Corona that engage the eye span a brightness range of over 10000 to 1, making them notoriously difficult to capture in a single picture. But this composite of 28 digital images - ranging in exposure time from 1/1000th to 2" - comes close to revealing the Crown of the Sun in all its glory.
The telescopic views were recorded near Kochenevo, Russia during the August 1 total Solar Eclipse and also show Solar Prominences extending just beyond the edge of the eclipsed Sun. Remarkably, features on the dark near side of the New Moon can also be made out, illuminated by sunlight reflected from a Full Earth".MareKromium
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Solar_Corona_vangorp_big.jpgSolar Corona58 visiteDa "NASA - Picture of the Day" del giorno 26 Luglio 2009:"Most photographs don't adequately portray the magnificence of the Sun's Corona. Seeing the Corona first-hand during a Total Solar Eclipse is best. The human eye can adapt to see features and extent that photographic film usually cannot.
Welcome, however, to the digital age. The above picture is a combination of 33 photographs that were digitally processed to highlight faint features of a Total Eclipse that occurred in March of 2006. The images of the Sun's Corona were digitally altered to enhance dim, outlying waves and filaments. Shadow seekers need not fret, though, since as yet there is no way that digital image processing can mimic the fun involved in experiencing a Total Solar Eclipse.
Last week, a spectacular Total Solar Eclipse occurred over Southern Asia, while the the next Total Solar Eclipse will be visible from the South Pacific on July, 11, 2010".MareKromium
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Solar_Corona~0.jpgDeep Coronal Holes106 visiteCaption NASA:"This ominous, dark shape sprawling across the face of the Sun is a Coronal Hole -- a low density region extending above the Surface where the Solar Magnetic Field opens freely into interplanetary space.
Studied extensively from space since the 1960s in UltraViolet and X-Ray Light, Coronal Holes are known to be the source of the high-speed Solar Wind (such as atoms and electrons which flow outward along the open Magnetic Field lines). During periods of low activity, Coronal Holes typically cover regions just above the Sun's Poles.
But this extensive Coronal Hole dominated the Sun's Northern Hemisphere earlier this week, captured here in Extreme UV Light by cameras onboard the Solar Dynamics Observatory. The solar wind streaming from this Coronal Hole triggered auroral displays on Earth".MareKromium
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Solar_Eclipse-2010.jpgMillennium's Annular Solar Eclipse54 visiteDa "NASA - Picture of the Day" del giorno 22 Gennaio 2010:"The Moon's shadow raced across planet Earth on January 15, 2010.
Observers within the central shadow track were able to witness an Annular Solar Eclipse as the Moon's apparent size was too small to completely cover the Sun. A visually dramatic "Ring of Fire", the annular phase lasted up to 11' and 8", depending on location: the longest Annular Solar Eclipse for the next 1000 years.
This picture of the Moon's silhouette just before mid-eclipse was taken within the eclipse path from the city of Kanyakumari at the southern tip of India. The telescopic image was made through a filter that blocks most Visible Light, but still transmits light from Hydrogen Atoms.
As a result, detailed mottling, or granulation, caused by heat convection in the Sun's Atmosphere can be seen around the dark Lunar Disk".MareKromium
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Solar_Eclipse-Tse2008_200_mo1_big.jpgAugust 2008 Total Solar Eclipse53 visiteCaption NASA:"For a moment on August 1st, the daytime sky grew dark along the path of a Total Solar Eclipse. While watching the geocentric celestial event from Mongolia, photographer Miloslav Druckmuller recorded multiple images with two separate cameras as the Moon blocked the bright solar disk and darkened the sky.
This final composition consists of 55 frames ranging in exposure time from 1/125 to 8 seconds. It spans nearly 12°, with the relative position of the Moon and Sun corresponding to mid-eclipse. On the left is bright planet Mercury, but many stars are also visible, including the Praesepe Star Cluster (also known as M44 or the Beehive Cluster) in Cancer, above and to the right of the silhouetted Moon. Remarkably, the nearly perfect conditions and wide range in individual exposures allow the composite picture to register the lunar surface and follow the delicate solar corona out to a distance of nearly 20 times the radius of the Sun. In fact, the composite presents a range in brightness beyond what the eye could see during the eclipse".MareKromium
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Solar_Eclipse~0.jpgA "Diamond Ring" among the clouds56 visiteDa "NASA - Picture of the Day" del giorno 8 Agosto 2009:"Cloudy skies over Wuhan, China hid the delicate Solar Corona during July's Total Eclipse of the Sun. Still, the Moon's silhouette was highlighted by these glistening diamonds as the Total Eclipse Phase ended. Caused by bright Sunlight streaming through dips and valleys in the irregular terrain along the Moon's edge, the effect is known as Baily's Beads, named after Francis Baily who called attention to the phenomenon in 1836.
The dramatic appearance of the beads at the beginning or end of a Total Solar Eclipse is also known as the Diamond Ring effect. In this remarkable image, a small, pinkish solar prominence can also be seen along the edge, below the diamonds".MareKromium
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Solar_Prominence-304erupt_crop.jpgSolar Eruption!53 visiteCaption NASA:"On September 29, 2008, this magnificent eruptive Solar Prominence lifted away from the Sun's Surface, unfurling into space over the course of several hours.
Suspended in twisted Magnetic Fields, the hot plasma structure is many times the size of planet Earth and was captured in this view by the Sun-watching STEREO (Ahead) Spacecraft.
The image was recorded in extreme ultraviolet light emitted by ionized Helium, an element originally identified in the Solar Spectrum. Seen against the brilliant Solar Surface in visible light, such prominences appear as dark filaments because they are relatively cool. But they are bright themselves when viewed against the blackness of space, arcing above the Sun's edge".MareKromium
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Solar_Prominence-SOHO.jpgSolar Prominence102 visiteCaption NASA:"What's that coming over the edge of the Sun? What might appear at first glance to be some sort of Sun monster is actually a Solar Prominence. The above Prominence, captured by the Sun-orbiting SOHO satellite earlier this year during an early stage of its eruption, rapidly became one of the largest ever on record.
Even as pictured, the Prominence is huge -- the Earth would easily fit inside. A Solar Prominence is a thin cloud of Solar Gas held just above the Surface by the Sun's Magnetic Field.
A "Quiescent Prominence" typically lasts about a month, while an "Eruptive Prominence" like the one developing above may erupt within hours into 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. As our Sun evolves toward Solar maximum over the next three years, more large eruptive prominences are expected".MareKromium
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Solar_Prominence-STEREO.jpgHuge Solar Prominence53 visiteCaption NASA:"What does a Solar Prominence look like in three dimensions? To help find out, NASA launched the STEREO satellites to keep a steady eye on the Sun from two different vantage points.
The STEREO satellites orbit the Sun nearly along Earth's orbit, but one (dubbed "Ahead" ---> Avanti) currently leads the Earth, while the other (dubbed "Behind" ---> "Dietro") currently trails. Three weeks ago, a powerful Prominence erupted and remained above the Sun for about 30 hours, allowing the STEREO satellites to get numerous views of it from different angles.
Pictured above is a High-Resolution image of the event from the STEREO "Ahead" satellite.
A video of the Prominence erupting as seen from both Spacecrafts can be found at http : // www . youtube . com / watch?v = _RjswBx6ysQ.
The unusually quiet nature of the Sun over the past two years has made large prominences like this relatively rare. The combined perspective of STEREO will help astronomers better understand the mechanisms for the creation and evolution of Prominences, Coronal Mass Ejections, and Solar Flares".
MareKromium
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Solar_Prominence.jpgSolar Prominence53 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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Solar_Prominence~0.jpgSolar Prominence66 visiteCaption NASA, da "NASA - Picture of the Day" del giorno 23 Marzo 2010:"Dramatic Prominences can sometimes be seen looming just beyond the edge of the Sun.
Such was the case last week as a Giant Prominence, visible above on the right, highlighted a Sun showing increased activity as it comes off an unusually quiet Solar Minimum. A changing carpet of hot gas is visible in the Chromosphere of the Sun in the above image taken in a very specific color of light emitted by Hydrogen.
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 right. Although very hot, Prominences typically appear dark when viewed against the Sun, since they are slightly cooler than the Surface.
A quiescent Prominence typically lasts about a month, and may erupt in a Coronal Mass Ejection (CME) expelling hot gas into the Solar System. The next day, the same prominence looked slightly different".MareKromium
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