Vega is the brightest star in the constellation Lyra, the fifth
brightest star in the night sky and the second brightest star in the
northern celestial hemisphere. It is a relatively close star at only 25
light-years from Earth, and one of the most luminous stars in the Sun's
neighbourhood. Vega has been extensively studied by astronomers. It was
the first star other than the Sun to have its photograph taken and the
first to have its spectrum photographed. Historically, Vega served as
the northern pole star around 12,000 BCE and will do so again at 13,727
CE. Vega is only about a tenth the age of the Sun, but it is evolving
so quickly that it has already approached the midpoint of its life
expectancy. It has an unusually low abundance of the elements with a
higher atomic number than that of helium. It is rotating rapidly with a
velocity of 274 km/s at the equator. Based on an observed excess
emission of infrared radiation, Vega appears to have a circumstellar
disk of dust. This dust is likely the result of collisions (pictured)
between objects in an orbiting debris disk, which is analogous to the
Kuiper belt in the Solar System. Irregularities in Vega's disk also
suggest the presence of at least one planet, likely to be about the
size of Jupiter.
Read the rest of this article:
<http://en.wikipedia.org/wiki/Vega>
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Today's selected anniversaries:
1777:
American Revolutionary War: The Americans led by General John Stark
routed British and Brunswick troops under Friedrich Baum at the Battle
of Bennington in Walloomsac, New York.
<http://en.wikipedia.org/wiki/Battle_of_Bennington>
1819:
Cavalry charged into a crowd of 60–80,000 gathered at St Peter's Field,
Manchester, England, to demand the reform of parliamentary
representation, killing 15 people and injuring 400–700 others.
<http://en.wikipedia.org/wiki/Peterloo_Massacre>
1896:
A group led by Skookum Jim Mason discovered gold near Dawson City,
Yukon, Canada, setting off the Klondike Gold Rush.
<http://en.wikipedia.org/wiki/Klondike_Gold_Rush>
1929:
A long-running dispute between Muslims and Jews over access to the
Western Wall in Jerusalem escalated into a week-long period of violent
riots throughout Palestine.
<http://en.wikipedia.org/wiki/1929_Palestine_riots>
1977:
Elvis Presley , "The King of Rock and Roll", was officially pronounced
dead at Baptist Memorial Hospital in Memphis, Tennessee, after he was
found unresponsive on the floor of his Graceland bathroom.
<http://en.wikipedia.org/wiki/Elvis_Presley>
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Wiktionary's word of the day:
gumshoe (n):
1. A sneaker or rubber overshoe.
2. (slang) A detective
<http://en.wiktionary.org/wiki/gumshoe>
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Wikiquote quote of the day:
Nine-tenths of tactics are certain, and taught in books: but the
irrational tenth is like the kingfisher flashing across the pool, and
that is the test of generals. It can only be ensured by instinct,
sharpened by thought practising the stroke so often that at the crisis
it is as natural as a reflex.
--T. E. Lawrence
<http://en.wikiquote.org/wiki/T._E._Lawrence>
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