| Piú viste - The Sun: just a star, like many others... |
The_Sun_-_Eclipse.jpgAt the Sun's Edge54 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
|
|
Solar_Corona.jpgIt's a "Corona", but it is not a "Beer", it's a "Crown", but is not a "Cola"...54 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
|
|
Sunspot-1002.jpgActive Region 100254 visiteCaption NASA:"Why has the Sun been so quiet recently? No one is sure. Our Sun has shown few active regions -- that house even fewer associated sunspots -- for over a year now, and such a period of relative calm is quite unusual.
What is well known is that our Sun is in a transitional period between solar cycles called a Solar Minimum, where solar activity has historically been reduced.
The stark lack of surface tumult is unusual even during a Solar Minimum, however, and activity this low has not been seen for many decades. A few days ago, however, a "Bona-Fide Active Region! -- complete with Sunspots --appeared and continues to rotate across the Sun's face. Visible above, this region, dubbed "Active Region 1002" (AR 1002), was imaged in ultraviolet light yesterday by the SOHO Spacecraft, which co-orbits the Sun near the Earth.
Besides the tranquility on the Sun's surface, recent data from the Ulysses Spacecraft, across the Solar System, indicate that the intensity of the Solar Wind blowing out from the Sun is at a 50 year low. Predictions hold, however, that our Sun will show more and more active regions containing more and more Sunspots and Flares until Solar Maximum occurs in about 4 years from now (such as in the year 2012)".MareKromium
|
|
Solar_Prominence-304erupt_crop.jpgSolar Eruption!54 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
|
|
The_Sun-00.jpgThe Sun in 3D54 visitenessun commentoMareKromium
|
|
The_Sun-01.jpgThe Sun in 3D54 visitenessun commentoMareKromium
|
|
The_Sun.JPGCold Sun? (All Filters; credits: SOHO & Dr M. Faccin)54 visitenessun commentoMareKromium
|
|
The_Sun-SS-HST.jpgThe Sun, Atlantis and Hubble54 visiteCaption NASA, da "NASA - Picture of the Day" del giorno 16 Maggio 2009:"On Wednesday, May 13th 2009, two, tiny, fast moving spots crossed an otherwise featureless Solar Disk. Not Sunspots though, the dark blemishes were silhouettes of the shuttle orbiter Atlantis and the Hubble Space Telescope side by side.
To record this sharp picture of the orbiting pair against the face of the Sun, astronomer Thierry Legault carefully set up his camera and telescope near the center of a 5 Km wide path of visibility about 100 Km South of Kennedy Space Center in Florida. He opened the shutter for 1/8000th second at 12:17 EDT, catching Atlantis and Hubble at a range of 600 Km while they were moving at a relative speed of about 7 Km-per-second.
The total duration of the transit (Sun crossing) was 0,8". Atlantis (top) is approaching Hubble prior to capturing the space telescope. Thursday (May 14, 2009), Astronauts began a series of spacewalks to perform the maintenance as part of the final mission to Hubble".MareKromium
|
|
Sungrazer-2010-SOHO.jpgSungrazer54 visiteCaption NASA:"Intense and overwhelming, the direct glare of the Sun is blocked by the smooth occulting disk in this image from the Sun-staring SOHO Spacecraft. Taken on January 3rd, 2010, an extreme UltraViolet image of the Sun to scale, is superimposed at the center of the disk. Beyond the disk's outer boundary, is a Sungrazer Comet, one of the brightest yet seen by SOHO.
The comet was discovered by an Australian Amateur Astronomer, Alan Watson, while examining earlier images from another Sun-watching Spacecraft, STEREO-A. Based on their orbits, Sungrazers are believed to belong to the Kreutz family of comets, created by successive break ups from a single large Parent Comet that passed very near the Sun in the twelfth century.
Subjected to strong Tidal Forces and intense Solar Heat, this Sungrazer did not survive its close encounter".MareKromium
|
|
The_Sun_in_Extreme_UV.jpgThe Sun in Extreme UV54 visiteThis wild-looking portrait of the Sun was made on March 30th, 2010, by the recently launched Solar Dynamics Observatory (SDO).
Shown in false-color, the composite view covers Extreme UltraViolet wavelengths and traces hot plasma at temperatures approaching 1 million Kelvins. At full resolution, SDO image data is intended to explore solar activity in unprecedented detail. In fact, SDO will send 1.5 terabytes of data back each day, equivalent to a daily download of about half a million MP3 songs.MareKromium
|
|
The_Sun-Texture.jpgThe "Texture" of the Sun54 visiteUp close, the Solar Surface is a striking patch work of "granules" in this very High Resolution picture of the quiet Sun. Caused by convection, the granules are hot, rising columns of plasma edged by dark lanes of cooler, descending plasma. But the HR view reveals that the dark lanes are dotted with many small, contrasting bright points. Constantly present on the Solar Surface, the bright points do not seem to be related to Sunspots that come and go with the Magnetic Solar Cycle.
Nonetheless, the bright points are regions of concentrated Magnetic Fields and are bright because the magnetic pressure opens a window to hotter deeper layers below the Photosphere. For scale, the white bar at the lower left corresponds to approx. 5000 Km across the Sun's Surface.
The sharp, narrow-band image was recorded in September, 2007 using the Swedish Solar Telescope on the astronomical island of La Palma.MareKromium
|
|
|
| 143 immagini su 12 pagina(e) |
 |
|
|
|
|
|
|
|
|
12 |
|
