Contemplating the Sun
Image Credit & Copyright: Steven Gilbert

Explanation: Have you contemplated your home star recently? Pictured above, a Sun partially eclipsed on the top left by the Moon is also seen eclipsed by earthlings contemplating the eclipse below. The above menagerie of silhouettes was taken from the Glenn Canyon National Recreational Area near Page, Arizona, USA, where park rangers and astronomers expounded on the unusual event to interested gatherers. Also faintly visible on the Sun’s disk, just to the lower right of the dark Moon’s disk, is a group of sunspots. Although exciting, some consider this event a warm-up act for next week’s chance to comtemplate the Sun — a much more rare partial eclipse by the planet Venus.

Mercury Spotting
Image Credit: SOHO - EIT Consortium, NASA

Explanation: Can you spot the planet? The diminutive disk of Mercury, the solar system’s innermost planet, spent about five hours crossing in front of the enormous solar disk in 2003, as viewed from the general vicinity of planet Earth. The Sun was above the horizon during the entire transit for observers in Europe, Africa, Asia, or Australia, and the horizon was certainly no problem for the sun-staring SOHO spacecraft. Seen as a dark spot, Mercury progresses from left to right (top panel to bottom) in these four images from SOHO’s extreme ultraviolet camera. The panels’ false-colors correspond to different wavelengths in the extreme ultraviolet which highlight regions above the Sun’s visible surface. This was the first of 14 transits of Mercury which will occur during the 21st century. Next week, however, an event much more rare but easier to spot will occur — a transit of Venus across the Sun. Need help spotting Mercury? Just click here.

A Partial Solar Eclipse over Texas
Image Credit & Copyright: Jimmy Westlake (Colorado Mountain College) & Linda Westlake

Explanation: It was a typical Texas sunset except that most of the Sun was missing. The location of the missing piece of the Sun was not a mystery — it was behind the Moon. Sunday night’s partial eclipse of the Sun by the Moon turned into one of the best photographed astronomical events in history. Gallery after online gallery is posting just one amazing eclipse image after another. Pictured above is possibly one of the more interesting posted images — a partially eclipsed Sun setting in a reddened sky behind brush and a windmill. The image was taken Sunday night from about 20 miles west of Sundown, Texas, USA, just after the ring of fire effect was broken by the Moon moving away from the center of the Sun. Coming early next month is an astronomical event that holds promise to be even more photographed — the last partial eclipse of the Sun by Venus until the year 2117.

A Partial Eclipse Over Manila Bay
Credit & Copyright: Armando Lee (Astron. League Philippines), F. Naelga Jr., 100 Hours of Astronomy (IYA2009)

Explanation: What’s happened to the setting Sun? An eclipse! In early 2009, the Moon eclipsed part of the Sun as visible from parts of Africa, Australia, and Asia. In particular the above image, taken from the Mall of Asia seawall, caught a partially eclipsed Sun setting over Manila Bay in the Philippines. Piers are visible in silhouette in the foreground. Eclipse chasers and well placed sky enthusiasts captured many other interesting and artistic images of the year’s only annular solar eclipse, including movies, eclipse shadow arrays, and rings of fire. Today parts of the Sun again will become briefly blocked by the Moon, again visible to some as a partial eclipse of a setting Sun. A small swath of Earth, however, will be exposed to the unusual ring of fire effect when the Moon is completely surrounded by the glowing light of the slightly larger Sun.

Sun vs. Super Moon
Image Credit & Copyright: Charlie Szabototh

Explanation: The Super Moon wins, by just a little, when its apparent size is compared to the Sun in this ingenious composite picture. To make it, the Full Moon on May 6 was photographed with the same camera and telescope used to image the Sun (with a dense solar filter!) on the following day. Of course, on May 6 the Moon was at perigee, the closest point to Earth in its eliptical orbit, making it the largest Full Moon of 2012. Two weeks later, on May 20, the Moon will be near apogee, the most distant point in its orbit, so by then it will be nearly at its smallest apparent size. It will also be a dark New Moon on that date. And for some the New Moon will be surprisingly easy to compare to the Sun, because on May 20 the first solar eclipse of 2012 will be visible from much of Asia, the Pacific, and North America. Along a path 240 to 300 kilometers wide, the eclipse will be annular. Near apogee the smaller silhouetted Moon will fit just inside the bright solar disk.

the-star-stuff:

Main Sequence Stars

The main sequence is the point in a star’s evolution during which it maintains a stable nuclear reaction. It is this stage during which a star will spend most of its life. Our Sun is a main sequence star. A main sequence star will experience only small fluctuations in luminosity and temperature. The amount of time a star spends in this phase depends on its mass. Large, massive stars will have a short main sequence stage while less massive stars will remain in main sequence much longer. Very massive stars will exhaust their fuel in only a few hundred million years. Smaller stars, like the Sun, will burn for several billion years during their main sequence stage. Very massive stars will become blue giants during their main sequence.

Images By NASA Goddard Photo and Video

Solar Flare in the Gamma-ray Sky
Credit: NASA, DOE, International Fermi LAT Collaboration

Explanation: What shines in the gamma-ray sky? The answer is usually the most exotic and energetic of astrophysical environments, like active galaxies powered by supermassive black holes, or incredibly dense pulsars, the spinning remnants of exploded stars. But on March 7, a powerful solar flare, one of a series of recent solar eruptions, dominated the gamma-ray sky at energies up to 1 billion times the energy of visible light photons. These two panels illustrate the intensity of that solar flare in all-sky images recorded by the orbiting Fermi Gamma-ray Space Telescope. On March 6, as on most days, the Sun was almost invisible to Fermi’s imaging detectors. But during the energetic X-class flare, it became nearly 100 times brighter than even the Vela Pulsar at gamma-ray energies. Now faded in Fermi’s view, the Sun will likely shine again in the gamma-ray sky as the solar activity cycle approaches its maximum.

Angry Sun Erupting
Image Credit & Copyright: Alan Friedman (Averted Imagination)

Explanation: It’s one of the baddest sunspot regions in years. Active Region 1429 may not only look, to some, like an angry bird — it has thrown off some of the most powerful flares and coronal mass ejections of the current solar cycle. The extended plumes from these explosions have even rained particles on the Earth’s magnetosphere that have resulted in colorful auroras. Pictured above, AR 1429 was captured in great detail in the Sun’s chromosphere three days ago by isolating a color of light emitted primarily by hydrogen. The resulting image is shown in inverted false color with dark regions being the brightest and hottest. Giant magnetically-channeled tubes of hot gas, some longer than the Earth, are known as spicules and can be seen carpeting the chromosphere. The light tendril just above AR 1429 is a cool filament hovering just over the active sunspot region. As solar maximum nears in the next few years, the increasingly wound and twisted magnetic field of the Sun may create even more furious active regions that chirp even more energetic puffs of solar plasma into our Solar System.

When a rather large-sized (M 3.6 class) flare occurred near the edge of the Sun, it blew out a gorgeous, waving mass of erupting plasma that swirled and twisted over a 90-minute period on February 24, 2011. This event was captured in extreme ultraviolet light by NASA’s Solar Dynamics Observatory spacecraft . Some of the material blew out into space and other portions fell back to the surface. (NASA/GSFC/SDO)