Supermassive black hole at the core of M87

A black hole is an astronomical body so compact that its gravity prevents anything, including light, from escaping. Black holes typically form when massive stars collapse at the end of their life cycle. In general relativity, crossing a black hole's event horizon traps an object inside but produces no locally detectable change. Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century. In 1916, the first solution of general relativity that would characterise a black hole was found. The presence of a black hole can be inferred through its interaction with matter and electromagnetic radiation. The first widely accepted black hole was Cygnus X-1, identified in 1971. Astronomers have since identified numerous stellar black hole candidates in binary systems and established that Sagittarius A*, a compact radio source at the core of the Milky Way, is a supermassive black hole of about 4.3 million solar masses. (Full article...)

Kiara St. James

• ... that transgender activist Kiara St. James (pictured) helped to end New York's Walking While Trans law?
• ... that a formerly best-selling title in the Fate franchise remained exclusive to Japan until an English fan translation was released a decade later?
• ... that German-born Katrin Bennhold has been a senior writer for The New York Times in three European capitals?
• ... that the school board of Charlotte, North Carolina, bought a defunct TV station in Florida and moved its equipment to start their own TV station?
• ... that the Torreón del Monje was the headquarters of a pigeon-shooting club?
• ... that Marvin Lowenthal went from being a silk-mill bobbin boy to writing a sixteen-century history of Jews in Germany?
• ... that Kreni-Promeni activists put up a billboard in Belgrade with attached cotton lungs that gradually darkened as they absorbed polluted air?
• ... that Shark Tank was adapted from a Japanese show that aimed to encourage entrepreneurship during a lengthy period of economic stagnation in the Japanese economy?
• ... that John Gauntlett was defeated in an election by his next-door neighbour, Charles Mompesson?

Garfield Sobers in 1956

• Cricketer Garfield Sobers (pictured) dies at the age of 89.
• A fire at a pub in Bangkok, Thailand, kills at least 33 people.
• In tennis, the Wimbledon Championships conclude with Linda Nosková and Jannik Sinner winning the women's and men's singles, respectively.
• Former emir of Qatar Hamad bin Khalifa Al Thani dies at the age of 74.
• China's orbital rocket booster Long March 10B becomes the first recovered after launch using a net-based recovery system.

July 17: Constitution Day in South Korea (1948); World Emoji Day

Ahmed Hassan al-Bakr

• 1771 – Dene men who were acting as guides to Samuel Hearne on his exploration of the Coppermine River in present-day Nunavut, Canada, massacred a group of about twenty Copper Inuit.
• 1863 – The New Zealand Wars resumed as British forces led by General Duncan Cameron began the invasion of the Waikato.
• 1968 – Led by Ahmed Hassan al-Bakr (pictured), the Arab Socialist Ba'ath Party overthrew Iraqi president Abdul Rahman Arif in a bloodless coup.
• 1994 – Brazil won the FIFA World Cup final against Italy 3–2 on penalties, following a 0–0 draw after extra time.
• 2007 – TAM Airlines Flight 3054 overran the runway at Congonhas Airport in São Paulo, Brazil, killing 199 people.