A bomb blast kills at least 69 people and injures more than 150 others in the Sadr City area of Baghdad, Iraq.
Iran and the United Kingdom (flags pictured) expel some of each other's diplomats, in the fallout of the disputed 2009 Iranian presidential election and the protests that followed.
A derailment and collision occurs between two trains on the Red Line of the Washington Metrorail, killing at least nine people and injuring more than 100 others.
American Lucas Glover wins the 2009 U.S. Open Golf Championship.
Yunus-bek Yevkurov, the President of the Russian Republic of Ingushetia, is critically wounded in an assassination attempt.
In cricket, Pakistan wins the 2009 ICC World Twenty20 world cup after beating Sri Lanka at Lord's Cricket Ground in London.
DID YOU KNOW
... that Saint Afan's Church, Llanafan (pictured), near Aberystwyth, Wales, was originally founded by Saint Afan in the 6th century?
... that masked wrestler Dos Caras, Jr. only defended the CMLL World Heavyweight Championship four times in 533 days?
... that the satellite GPS IIR-1, intended to become part of the United States Air Force Global Positioning System, was destroyed 13 seconds after launch?
... that the 1979 Australian vampire-science fiction film Thirst drew influence from sources as diverse as Elizabeth Báthory and Soylent Green?
... that the current minister at the First Presbyterian Church in Marcellus, New York, was ordained in 1956?
... that Dublin's Windmill Lane Studios is regularly visited by tourists wishing to view the U2-inspired graffiti adorning the walls?
... that Prescott, Arizona, Mayor Sam Steiger was criminally prosecuted for painting a crosswalk between the local courthouse and the saloons on Whiskey Row?
A WHITE DWARF
A white dwarf is a small star composed mostly of electron-degenerate matter. Because a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth, it is very dense. Their faint luminosity comes from the emission of stored heat. They comprise roughly 6% of all known stars in the solar neighborhood. The unusual faintness of white dwarfs was first recognized in 1910 by Henry Norris Russell, Edward Charles Pickering and Williamina Fleming. White dwarfs are thought to be the final evolutionary state of all stars whose mass is not too high. The material in a white dwarf no longer undergoes fusion reactions, so the star has no source of energy, nor is it supported against gravitational collapse by the heat generated by fusion. It is supported only by electron degeneracy pressure, causing it to be extremely dense. The physics of degeneracy yields a maximum mass for a nonrotating white dwarf, the Chandrasekhar limit—approximately 1.4 solar masses—beyond which it cannot be supported by degeneracy pressure. Over a very long time, a white dwarf will cool to temperatures at which it will no longer be visible, and become a cold black dwarf. (more...)
